ASP.NET2.0打通文件图片处理任督二脉
1.最简单的单文件上传(没花头)
2.多文件上传
3.客户端检查上传文件类型(以上传图片为例)
4.服务器端检查上传文件类型(以上传图片为例)
5.服务器端检查上传文件类型(可以检测真正文件名)
6.上传文件文件名唯一性处理(时间戳+SessionID)
7.上传图片生成等比例缩略图
8.上传图片加水印(文字水印，图片水印，文字+图片水印)
9.
1.最简单的单文件上传(没花头)
效果图：
说明：这是最基本的文件上传，在asp.net1.x中没有这个FileUpload控件，只有html的上传控件，那时候要把html控件转化为服务器控件，很不好用。其实所有文件上传的美丽效果都是从这个FileUpload控件衍生，第一个例子虽然简单却是根本。
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath = Server.MapPath("images/") + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception ex)
{
this.lb_info.Text = "上传发生错误！原因是：" + ex.ToString();
}
}
}
前台代码：
<table style="width: 343px">
<tr>
<td style="width: 100px">
单文件上传</td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 100px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
</td>
<td style="width: 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" /></td>
</tr>
<tr>
<td style="width: 100px; height: 21px;">
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style="width: 100px; height: 21px">
</td>
</tr>
</table>
2.多文件上传
效果图：
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
if ((FileUpload1.PostedFile.FileName == "" && FileUpload2.PostedFile.FileName == "")&&FileUpload3.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
HttpFileCollection myfiles = Request.Files;
for (int i = 0; i < myfiles.Count; i++)
{
HttpPostedFile mypost = myfiles[i];
try
{
if (mypost.ContentLength > 0)
{
string filepath = mypost.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath = Server.MapPath("images/") + filename;
mypost.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
}
}
}
前台代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>多文件上传 清清月儿http://blog.csdn.net/21aspnet/</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table style="width: 343px">
<tr>
<td style="width: 100px">
多文件上传</td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 100px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="475px" />
</td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 100px">
<asp:FileUpload ID="FileUpload2" runat="server" Width="475px" /></td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 100px">
<asp:FileUpload ID="FileUpload3" runat="server" Width="475px" /></td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="一起上传" />
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style="width: 100px">
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
3.客户端检查上传文件类型(以上传图片为例)
效果图：
后台代码和1.最简单的单文件上传一样；
前台代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>清清月儿 http://blog.csdn.net/21aspnet</title>
<script language="javascript">
function Check_FileType()
{
var str=document.getElementById("FileUpload1").value;
var pos = str.lastIndexOf(".");
var lastname = str.substring(pos,str.length)
if (lastname.toLowerCase()!=".jpg" && lastname.toLowerCase()!=".gif")
{
alert("您上传的文件类型为"+lastname+"，图片必须为.jpg,.gif类型");
return false;
}
else
{
return true;
}
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<table style="width: 343px">
<tr>
<td style="width: 104px">
文件上传判断</td>
<td style="width: 100px">
</td>
</tr>
<tr>
<td style="width: 104px">
<asp:FileUpload ID="FileUpload1" runat="server" Width="400px" />
</td>
<td style="width: 100px">
<asp:Button ID="bt_upload" runat="server" OnClick="bt_upload_Click" Text="上传" OnClientClick="return Check_FileType()"/></td>
</tr>
<tr>
<td style="width: 104px; height: 21px;">
<asp:Label ID="lb_info" runat="server" ForeColor="Red" Width="183px"></asp:Label></td>
<td style="width: 100px; height: 21px">
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
说明：点击上传时先触发客户端事件Check_FileType；
4.服务器端检查上传文件类型(以上传图片为例)
效果图：
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
if (IsAllowedExtension(FileUpload1) == true)
{
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath = Server.MapPath("images/") + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
else
{
this.lb_info.Text = "请上传图片";
}
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
public static bool IsAllowedExtension(FileUpload hifile)
{
string strOldFilePath = "", strExtension = "";
string[] arrExtension = { ".gif", ".jpg", ".jpeg", ".bmp", ".png" };
if (hifile.PostedFile.FileName != string.Empty)
{
strOldFilePath = hifile.PostedFile.FileName;
strExtension = strOldFilePath.Substring(strOldFilePath.LastIndexOf("."));
for (int i = 0; i < arrExtension.Length; i++)
{
if (strExtension.Equals(arrExtension[i]))
{
return true;
}
}
}
return false;
}
}
5.服务器端检查上传文件类型(可以检测真正文件名)
其实方法4并不好，因为用户可以把XXX.txt伪装为XXX.jpg。
效果图：
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
//清清月儿 http://blog.csdn.net/21aspnet
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
if (IsAllowedExtension(FileUpload1) == true)
{
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath = Server.MapPath("images/") + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
else
{
this.lb_info.Text = "请上传图片";
}
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
public static bool IsAllowedExtension(FileUpload hifile)
{
System.IO.FileStream fs = new System.IO.FileStream(hifile.PostedFile.FileName, System.IO.FileMode.Open, System.IO.FileAccess.Read);
System.IO.BinaryReader r = new System.IO.BinaryReader(fs);
string fileclass = "";
byte buffer;
try
{
buffer = r.ReadByte();
fileclass = buffer.ToString();
buffer = r.ReadByte();
fileclass += buffer.ToString();
}
catch
{
}
r.Close();
fs.Close();
if (fileclass == "255216" || fileclass == "7173")//说明255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar
{
return true;
}
else
{
return false;
}
}
}
6.上传文件文件名唯一性处理(时间戳+SessionID)
效果图：
说明：年月日时分秒+临时session+原文件名 如果大家怕还会重复可以加GUID
后台代码：
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
FileUpload1.PostedFile.SaveAs(serverpath);
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
注：GUID的方法：Guid myGuid=Guid.NewGuid();
7.上传图片生成等比例缩略图
效果图：
缩略图代码：
ImageThumbnail.cs
using System;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;
public class ImageThumbnail
{
public Image ResourceImage;
private int ImageWidth;
private int ImageHeight;
public string ErrorMessage;
public ImageThumbnail(string ImageFileName)
{
ResourceImage = Image.FromFile(ImageFileName);
ErrorMessage = "";
}
public bool ThumbnailCallback()
{
return false;
}
// 方法1，按大小
public bool ReducedImage(int Width, int Height, string targetFilePath)
{
try
{
Image ReducedImage;
Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
ReducedImage = ResourceImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
ReducedImage.Dispose();
return true;
}
catch (Exception e)
{
ErrorMessage = e.Message;
return false;
}
}
// 方法2，按百分比 缩小60% Percent为0.6 targetFilePath为目标路径
public bool ReducedImage(double Percent, string targetFilePath)
{
try
{
Image ReducedImage;
Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
ImageWidth = Convert.ToInt32(ResourceImage.Width * Percent);
ImageHeight = (ResourceImage.Height)*ImageWidth/ ResourceImage.Width;//等比例缩放
ReducedImage = ResourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
ReducedImage.Dispose();
return true;
}
catch (Exception e)
{
ErrorMessage = e.Message;
return false;
}
}
}
后台代码：
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void bt_upload_Click(object sender, EventArgs e)
{
try
{
if (FileUpload1.PostedFile.FileName == "")
{
this.lb_info.Text = "请选择文件！";
}
else
{
string filepath = FileUpload1.PostedFile.FileName;
string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1);
string serverpath1 = Server.MapPath("images/") + filename;
string serverpath2 = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename;
FileUpload1.PostedFile.SaveAs(serverpath1);
ImageThumbnail img = new ImageThumbnail(filepath);
img.ReducedImage(0.4, serverpath2);//0.4表示缩小40%
this.lb_info.Text = "上传成功！";
}
}
catch (Exception error)
{
this.lb_info.Text = "上传发生错误！原因：" + error.ToString();
}
}
}
8.上传图片加水印(文字水印，图片水印，文字+图片水印)
效果图：
原图
水印
给图片加水印以后（注意右上角+正下方）
代码：DrawImg.cs 出自http:
//
www.codeproject.com/csharp/watermark.asp
using
System;
using
System.Drawing;
using
System.Drawing.Imaging;
using
System.Drawing.Drawing2D;
public
class
DrawImg
{
private string WorkingDirectory = string.Empty ; //路径 private string ImageName = string.Empty; //被处理的图片 private string ImageWater = string.Empty; //水印图片 private string FontString = string.Empty; //水印文字 
enum DealType{NONE,WaterImage,WaterFont,DoubleDo}; //枚举命令
private DealType dealtype; public DrawImg() {} public string PublicWorkingDirectory { get { return WorkingDirectory;
} set { WorkingDirectory = value; } } public string PublicImageName { get { return ImageName; } set { ImageName = value; } } public string PublicImageWater { get { return ImageWater; } set //设置了水印图片的话说明是要水印图片效果的 { dealtype = DealType.WaterImage; ImageWater = value; } } public string PublicFontString { get { return FontString; } set //设置了水印文字的话说明是要水印文字效果的 { dealtype = DealType.WaterFont; FontString = value; } } public void DealImage() { IsDouble(); switch( dealtype ) { case DealType.WaterFont: WriteFont(); break; case DealType.WaterImage: WriteImg(); break; case DealType.DoubleDo: WriteFontAndImg(); break; } } private void IsDouble() { if(ImageWater+""!="" && FontString+""!="") { dealtype = DealType.DoubleDo; } } private void WriteFont() { //set a working directory //string WorkingDirectory = @"C:\Watermark_src\WaterPic"; //define a string of text to use as the Copyright message //string Copyright = "Copyright ?2002 - AP Photo/David Zalubowski"; //create a image object containing the photograph to watermark Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName); int phWidth = imgPhoto.Width; int phHeight = imgPhoto.Height; //create a Bitmap the Size of the original photograph Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //load the Bitmap into a Graphics object Graphics grPhoto = Graphics.FromImage(bmPhoto); //------------------------------------------------------------ //Step #1 - Insert Copyright message //------------------------------------------------------------ //Set the rendering quality for this Graphics object grPhoto.SmoothingMode = SmoothingMode.AntiAlias; //Draws the photo Image object at original size to the graphics object. grPhoto.DrawImage( imgPhoto, // Photo Image object new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure 0, // x-coordinate of the portion of the source image to draw. 0, // y-coordinate of the portion of the source image to draw. phWidth, // Width of the portion of the source image to draw. phHeight, // Height of the portion of the source image to draw. GraphicsUnit.Pixel); // Units of measure //------------------------------------------------------- //to maximize the size of the Copyright message we will //test multiple Font sizes to determine the largest posible //font we can use for the width of the Photograph //define an array of point sizes you would like to consider as possiblities //------------------------------------------------------- int[] sizes = new int[]{16,14,12,10,8,6,4}; Font crFont = null; SizeF crSize = new SizeF(); //Loop through the defined sizes checking the length of the Copyright string //If its length in pixles is less then the image width choose this Font size. for (int i=0 ;i<7; i++) { //set a Font object to Arial (i)pt, Bold //crFont = new Font("arial", sizes[i], FontStyle.Bold); crFont = new Font("arial",sizes[i],FontStyle.Bold); //Measure the Copyright string in this Font crSize = grPhoto.MeasureString(FontString, crFont); if((ushort)crSize.Width < (ushort)phWidth) break; } //Since all photographs will have varying heights, determine a //position 5% from the bottom of the image int yPixlesFromBottom = (int)(phHeight *.05); //Now that we have a point size use the Copyrights string height //to determine a y-coordinate to draw the string of the photograph float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2)); //Determine its x-coordinate by calculating the center of the width of the image float xCenterOfImg = (phWidth/2); //Define the text layout by setting the text alignment to centered StringFormat StrFormat = new StringFormat(); StrFormat.Alignment = StringAlignment.Center; //define a Brush which is semi trasparent black (Alpha set to 153) SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0)); //Draw the Copyright string grPhoto.DrawString(FontString, //string of text crFont, //font semiTransBrush2, //Brush new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position StrFormat); //define a Brush which is semi trasparent white (Alpha set to 153) SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255)); //Draw the Copyright string a second time to create a shadow effect //Make sure to move this text 1 pixel to the right and down 1 pixel grPhoto.DrawString(FontString, //string of text crFont, //font semiTransBrush, //Brush new PointF(xCenterOfImg,yPosFromBottom), //Position StrFormat); imgPhoto = bmPhoto; grPhoto.Dispose(); //save new image to file system. imgPhoto.Save(WorkingDirectory + ImageName + "_finally.jpg", ImageFormat.Jpeg); imgPhoto.Dispose(); //Text alignment } private void WriteImg() { //set a working directory //string WorkingDirectory = @"C:\Watermark_src\WaterPic"; //create a image object containing the photograph to watermark Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName); int phWidth = imgPhoto.Width; int phHeight = imgPhoto.Height; //create a Bitmap the Size of the original photograph Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //load the Bitmap into a Graphics object Graphics grPhoto = Graphics.FromImage(bmPhoto); //create a image object containing the watermark Image imgWatermark = new Bitmap(WorkingDirectory + ImageWater); int wmWidth = imgWatermark.Width; int wmHeight = imgWatermark.Height; //Set the rendering quality for this Graphics object grPhoto.SmoothingMode = SmoothingMode.AntiAlias; //Draws the photo Image object at original size to the graphics object. grPhoto.DrawImage( imgPhoto, // Photo Image object new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure 0, // x-coordinate of the portion of the source image to draw. 0, // y-coordinate of the portion of the source image to draw. phWidth, // Width of the portion of the source image to draw. phHeight, // Height of the portion of the source image to draw. GraphicsUnit.Pixel); // Units of measure //------------------------------------------------------------ //Step #2 - Insert Watermark image //------------------------------------------------------------ //Create a Bitmap based on the previously modified photograph Bitmap Bitmap bmWatermark = new Bitmap(bmPhoto); bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //Load this Bitmap into a new Graphic Object Graphics grWatermark = Graphics.FromImage(bmWatermark); //To achieve a transulcent watermark we will apply (2) color //manipulations by defineing a ImageAttributes object and //seting (2) of its properties. ImageAttributes imageAttributes = new ImageAttributes(); //The first step in manipulating the watermark image is to replace //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0) //to do this we will use a Colormap and use this to define a RemapTable ColorMap colorMap = new ColorMap(); //My watermark was defined with a background of 100% Green this will //be the color we search for and replace with transparency colorMap.OldColor = Color.FromArgb(255, 0, 255, 0); colorMap.NewColor = Color.FromArgb(0, 0, 0, 0); ColorMap[] remapTable = {colorMap}; imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap); //The second color manipulation is used to change the opacity of the //watermark. This is done by applying a 5x5 matrix that contains the //coordinates for the RGBA space. By setting the 3rd row and 3rd column //to 0.3f we achive a level of opacity float[][] colorMatrixElements = { new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}}; ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements); imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap); //For this example we will place the watermark in the upper right //hand corner of the photograph. offset down 10 pixels and to the //left 10 pixles int xPosOfWm = ((phWidth - wmWidth)-10); int yPosOfWm = 10; grWatermark.DrawImage(imgWatermark, new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position 0, // x-coordinate of the portion of the source image to draw. 0, // y-coordinate of the portion of the source image to draw. wmWidth, // Watermark Width wmHeight, // Watermark Height GraphicsUnit.Pixel, // Unit of measurment imageAttributes); //ImageAttributes Object //Replace the original photgraphs bitmap with the new Bitmap imgPhoto = bmWatermark; grPhoto.Dispose(); grWatermark.Dispose(); //save new image to file system. imgPhoto.Save(WorkingDirectory + ImageName +"_finally.jpg", ImageFormat.Jpeg); imgPhoto.Dispose(); imgWatermark.Dispose(); } private void WriteFontAndImg() { //create a image object containing the photograph to watermark Image imgPhoto = Image.FromFile(WorkingDirectory + ImageName); int phWidth = imgPhoto.Width; int phHeight = imgPhoto.Height; //create a Bitmap the Size of the original photograph Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //load the Bitmap into a Graphics object Graphics grPhoto = Graphics.FromImage(bmPhoto); //create a image object containing the watermark Image imgWatermark = new Bitmap(WorkingDirectory + ImageWater); int wmWidth = imgWatermark.Width; int wmHeight = imgWatermark.Height; //------------------------------------------------------------ //Step #1 - Insert Copyright message //------------------------------------------------------------ //Set the rendering quality for this Graphics object grPhoto.SmoothingMode = SmoothingMode.AntiAlias; //Draws the photo Image object at original size to the graphics object. grPhoto.DrawImage( imgPhoto, // Photo Image object new Rectangle(0, 0, phWidth, phHeight), // Rectangle structure 0, // x-coordinate of the portion of the source image to draw. 0, // y-coordinate of the portion of the source image to draw. phWidth, // Width of the portion of the source image to draw. phHeight, // Height of the portion of the source image to draw. GraphicsUnit.Pixel); // Units of measure //------------------------------------------------------- //to maximize the size of the Copyright message we will //test multiple Font sizes to determine the largest posible //font we can use for the width of the Photograph //define an array of point sizes you would like to consider as possiblities //------------------------------------------------------- int[] sizes = new int[]{16,14,12,10,8,6,4}; Font crFont = null; SizeF crSize = new SizeF(); //Loop through the defined sizes checking the length of the Copyright string //If its length in pixles is less then the image width choose this Font size. for (int i=0 ;i<7; i++) { //set a Font object to Arial (i)pt, Bold crFont = new Font("arial", sizes[i], FontStyle.Bold); //Measure the Copyright string in this Font crSize = grPhoto.MeasureString(FontString, crFont); if((ushort)crSize.Width < (ushort)phWidth) break; } //Since all photographs will have varying heights, determine a //position 5% from the bottom of the image int yPixlesFromBottom = (int)(phHeight *.05); //Now that we have a point size use the Copyrights string height //to determine a y-coordinate to draw the string of the photograph float yPosFromBottom = ((phHeight - yPixlesFromBottom)-(crSize.Height/2)); //Determine its x-coordinate by calculating the center of the width of the image float xCenterOfImg = (phWidth/2); //Define the text layout by setting the text alignment to centered StringFormat StrFormat = new StringFormat(); StrFormat.Alignment = StringAlignment.Center; //define a Brush which is semi trasparent black (Alpha set to 153) SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0)); //Draw the Copyright string grPhoto.DrawString(FontString, //string of text crFont, //font semiTransBrush2, //Brush new PointF(xCenterOfImg+1,yPosFromBottom+1), //Position StrFormat); //define a Brush which is semi trasparent white (Alpha set to 153) SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255)); //Draw the Copyright string a second time to create a shadow effect //Make sure to move this text 1 pixel to the right and down 1 pixel grPhoto.DrawString(FontString, //string of text crFont, //font semiTransBrush, //Brush new PointF(xCenterOfImg,yPosFromBottom), //Position StrFormat); //Text alignment //------------------------------------------------------------ //Step #2 - Insert Watermark image //------------------------------------------------------------ //Create a Bitmap based on the previously modified photograph Bitmap Bitmap bmWatermark = new Bitmap(bmPhoto); bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); //Load this Bitmap into a new Graphic Object Graphics grWatermark = Graphics.FromImage(bmWatermark); //To achieve a transulcent watermark we will apply (2) color //manipulations by defineing a ImageAttributes object and //seting (2) of its properties. ImageAttributes imageAttributes = new ImageAttributes(); //The first step in manipulating the watermark image is to replace //the background color with one that is trasparent (Alpha=0, R=0, G=0, B=0) //to do this we will use a Colormap and use this to define a RemapTable ColorMap colorMap = new ColorMap(); //My watermark was defined with a background of 100% Green this will //be the color we search for and replace with transparency colorMap.OldColor = Color.FromArgb(255, 0, 255, 0); colorMap.NewColor = Color.FromArgb(0, 0, 0, 0); ColorMap[] remapTable = {colorMap}; imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap); //The second color manipulation is used to change the opacity of the //watermark. This is done by applying a 5x5 matrix that contains the //coordinates for the RGBA space. By setting the 3rd row and 3rd column //to 0.3f we achive a level of opacity float[][] colorMatrixElements = { new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.3f, 0.0f}, new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}}; ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements); imageAttributes.SetColorMatrix(wmColorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap); //For this example we will place the watermark in the upper right //hand corner of the photograph. offset down 10 pixels and to the //left 10 pixles int xPosOfWm = ((phWidth - wmWidth)-10); int yPosOfWm = 10; grWatermark.DrawImage(imgWatermark, new Rectangle(xPosOfWm,yPosOfWm,wmWidth,wmHeight), //Set the detination Position 0, // x-coordinate of the portion of the source image to draw. 0, // y-coordinate of the portion of the source image to draw. wmWidth, // Watermark Width wmHeight, // Watermark Height GraphicsUnit.Pixel, // Unit of measurment imageAttributes); //ImageAttributes Object //Replace the original photgraphs bitmap with the new Bitmap imgPhoto = bmWatermark; grPhoto.Dispose(); grWatermark.Dispose(); //save new image to file system. imgPhoto.Save(WorkingDirectory + ImageName +"_finally.jpg", ImageFormat.Jpeg); imgPhoto.Dispose(); imgWatermark.Dispose(); }
}
//
水印图片加水印文字
//
ReDrawImg img = new ReDrawImg();
//
img .PublicWorkingDirectory = @"C:\Watermark_src\WaterPic\";
//
img .PublicImageName = "watermark_photo.jpg";
//
img .PublicImageWater = "watermark.bmp";
//
img .PublicFontString = "清清月儿";
//
img .DealImage();
//
水印文字
ReDrawImg img
=
new
ReDrawImg(); img .PublicWorkingDirectory
=
@"
C:\Watermark_src\WaterPic\
"
; img .PublicImageName
=
"
watermark_photo.jpg
"
; img .PublicFontString
=
@"
清清月儿
"
; img .DealImage();
//
水印图片
//
ReDrawImg img = new ReDrawImg();
//
img .PublicWorkingDirectory = @"C:\Watermark_src\WaterPic\";
//
img .PublicImageName = "watermark_photo.jpg";
//
img .PublicImageWater = "watermark.bmp";
//
img .DealImage();
后台代码：
using
System;
using
System.Data;
using
System.Configuration;
using
System.Collections;
using
System.Web;
using
System.Web.Security;
using
System.Web.UI;
using
System.Web.UI.WebControls;
using
System.Web.UI.WebControls.WebParts;
using
System.Web.UI.HtmlControls;
public
partial
class
_Default : System.Web.UI.Page
{ protected void Page_Load(object sender, EventArgs e) { } protected void bt_upload_Click(object sender, EventArgs e) { try { if (FileUpload1.PostedFile.FileName == "") { this.lb_info.Text = "请选择文件！"; } else { string filepath = FileUpload1.PostedFile.FileName; string filename = filepath.Substring(filepath.LastIndexOf("\\") + 1); string serverpath1 = Server.MapPath("images/") + filename; //string serverpath2 = Server.MapPath("images/") + System.DateTime.Now.ToString("yyy-MM-dd-hh-mm-ss") + Session.SessionID + filename; FileUpload1.PostedFile.SaveAs(serverpath1); //ImageThumbnail img = new ImageThumbnail(filepath); //img.ReducedImage(0.4, serverpath2); DrawImg img = new DrawImg(); img.PublicWorkingDirectory = Server.MapPath("images/"); img.PublicImageName = filename; img.PublicFontString = "http://blog.csdn.net/21aspnet"; img.PublicImageWater = "yyy.jpg"; img.DealImage(); this.lb_info.Text = "上传成功！"; } } catch (Exception error) { this.lb_info.Text = "上传发生错误！原因：" + error.ToString(); } }}