C#.NET 缩略图处理类CutImage
using
System;
using
System.Collections.Generic;
using
System.Text;
using
System.IO;
using
System.Drawing;
using
System.Drawing.Imaging;
using
System.Drawing.Drawing2D;
namespace
Pub.Class {
///
<summary>
///
缩图处理类
///
</summary>
public
class
CutImage
{
#region
构造函数
public
CutImage() { }
#endregion
#region
私有成员
private
int
width;
private
int
height;
private
int
size;
private
string
errMSG;
#endregion
#region
公共属性
///
<summary>
///
图片宽度
///
</summary>
public
int
Width {
get
{
return
width; }
set
{ width
=
value; } }
///
<summary>
///
图片高度
///
</summary>
public
int
Height {
get
{
return
height; }
set
{ Height
=
value; } }
///
<summary>
///
图片尺寸
///
</summary>
public
int
Size {
get
{
return
size; }
set
{ size
=
value; } }
///
<summary>
///
错误消息
///
</summary>
public
string
ErrMSG {
get
{
return
this
.errMSG; }
set
{
this
.errMSG
=
value; } }
#endregion
#region
公共方法
///
<summary>
///
获取图片信息
///
</summary>
///
<param name="imagePath">
图片地址
</param>
///
<returns>
成功true失败false
</returns>
public
bool
GetImage(
string
imagePath) {
try
{
System.Drawing.Image image
=
System.Drawing.Image.FromFile(imagePath);
this
.width
=
image.Width;
this
.height
=
image.Height;
image.Dispose();
FileStream fs
=
new
FileStream(imagePath, FileMode.Open, FileAccess.Read);
this
.size
=
(
int
)fs.Length;
fs.Close();
return
true
;
}
catch
(Exception ex) {
this
.errMSG
=
ex.ToString();
return
false
;
}
}
///
<summary>
///
按宽X长比例切图
///
</summary>
///
<param name="imagePath">
源图地址
</param>
///
<param name="savePath">
新图地址
</param>
///
<param name="cutWidth">
宽度
</param>
///
<param name="cutHeight">
高度
</param>
///
<returns>
成功true失败false
</returns>
public
bool
CutImageCustomMin(
string
imagePath,
string
savePath,
int
cutWidth,
int
cutHeight) {
try
{
System.Drawing.Image objImage
=
System.Drawing.Image.FromFile(imagePath);
float
x
=
objImage.Width;
float
y
=
objImage.Height;
float
xPercent
=
x
/
cutWidth;
float
yPercent
=
y
/
cutHeight;
if
(xPercent
<
yPercent) {
this
.width
=
(
int
)((x
*
cutHeight)
/
y);
this
.height
=
cutHeight;
}
else
{
this
.width
=
cutWidth;
this
.height
=
(
int
)((cutWidth
*
y)
/
x);
}
System.Drawing.Image newimage
=
new
Bitmap(objImage.Width, objImage.Height, PixelFormat.Format32bppRgb);
Graphics g
=
Graphics.FromImage(newimage);
g.DrawImage(objImage,
0
,
0
, objImage.Width, objImage.Height);
g.Dispose();
System.Drawing.Image thumbImage
=
newimage.GetThumbnailImage(
this
.width,
this
.height,
null
, IntPtr.Zero);
thumbImage.Save(savePath, objImage.RawFormat);
objImage.Dispose();
newimage.Dispose();
thumbImage.Dispose();
FileStream fs
=
new
FileStream(savePath, FileMode.Open, FileAccess.Read);
this
.size
=
(
int
)fs.Length;
fs.Close();
return
true
;
}
catch
(Exception ex) {
this
.errMSG
=
ex.ToString();
return
false
;
}
}
///
<summary>
///
按宽X长比例切图
///
</summary>
///
<param name="imagePath">
源图地址
</param>
///
<param name="savePath">
新图地址
</param>
///
<param name="cutWidth">
宽度
</param>
///
<param name="cutHeight">
高度
</param>
///
<returns>
成功true失败false
</returns>
public
bool
CutImageCustom(
string
imagePath,
string
savePath,
int
cutWidth,
int
cutHeight) {
try
{
System.Drawing.Image objImage
=
System.Drawing.Image.FromFile(imagePath);
float
x
=
objImage.Width;
float
y
=
objImage.Height;
float
xPercent
=
x
/
cutWidth;
float
yPercent
=
y
/
cutHeight;
if
(xPercent
<
yPercent) {
this
.width
=
(
int
)((x
*
cutHeight)
/
y);
this
.height
=
cutHeight;
}
else
{
this
.width
=
cutWidth;
this
.height
=
(
int
)((cutWidth
*
y)
/
x);
}
Bitmap newimage
=
new
Bitmap(
this
.width,
this
.height, PixelFormat.Format32bppRgb);
newimage.SetResolution(72f, 72f);
Graphics gdiobj
=
Graphics.FromImage(newimage);
gdiobj.CompositingQuality
=
CompositingQuality.HighQuality;
gdiobj.SmoothingMode
=
SmoothingMode.HighQuality;
gdiobj.InterpolationMode
=
InterpolationMode.HighQualityBicubic;
gdiobj.PixelOffsetMode
=
PixelOffsetMode.HighQuality;
gdiobj.FillRectangle(
new
SolidBrush(Color.White),
0
,
0
,
this
.width,
this
.height);
Rectangle destrect
=
new
Rectangle(
0
,
0
,
this
.width,
this
.height);
gdiobj.DrawImage(objImage, destrect,
0
,
0
, objImage.Width, objImage.Height, GraphicsUnit.Pixel);
gdiobj.Dispose();
System.Drawing.Imaging.EncoderParameters ep
=
new
System.Drawing.Imaging.EncoderParameters(
1
);
ep.Param[
0
]
=
new
System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, (
long
)
100
);
ImageCodecInfo[] codecs
=
ImageCodecInfo.GetImageEncoders();
ImageCodecInfo ici
=
null
;
foreach
(ImageCodecInfo codec
in
codecs) {
if
(codec.MimeType
==
"
image/jpeg
"
) { ici
=
codec; }
}
if
(ici
!=
null
) newimage.Save(savePath, ici, ep);
else
newimage.Save(savePath, objImage.RawFormat);
objImage.Dispose();
newimage.Dispose();
FileStream fs
=
new
FileStream(savePath, FileMode.Open, FileAccess.Read);
this
.size
=
(
int
)fs.Length;
fs.Close();
return
true
;
}
catch
(Exception ex) {
this
.errMSG
=
ex.ToString();
return
false
;
}
}
///
<summary>
///
将图片缩放到指定的宽度
///
</summary>
///
<param name="imagePath">
源图地址
</param>
///
<param name="savePath">
新图地址
</param>
///
<param name="square">
宽度
</param>
///
<returns>
成功true失败false
</returns>
public
bool
CutImageByWidth(
string
imagePath,
string
savePath,
int
square) {
try
{
int
cutWidth
=
square;
System.Drawing.Image objImage
=
System.Drawing.Image.FromFile(imagePath);
float
x
=
objImage.Width;
float
y
=
objImage.Height;
this
.width
=
cutWidth;
this
.height
=
(
int
)((cutWidth
*
y)
/
x);
System.Drawing.Image newimage
=
new
Bitmap(objImage.Width, objImage.Height, PixelFormat.Format32bppRgb);
Graphics g
=
Graphics.FromImage(newimage);
g.DrawImage(objImage,
0
,
0
, objImage.Width, objImage.Height);
g.Dispose();
System.Drawing.Image thumbImage
=
newimage.GetThumbnailImage(
this
.width,
this
.height,
null
, IntPtr.Zero);
thumbImage.Save(savePath, objImage.RawFormat);
objImage.Dispose();
newimage.Dispose();
thumbImage.Dispose();
FileStream fs
=
new
FileStream(savePath, FileMode.Open, FileAccess.Read);
this
.size
=
(
int
)fs.Length;
fs.Close();
return
true
;
}
catch
(Exception ex) {
this
.errMSG
=
ex.ToString();
return
false
;
}
}
///
<summary>
///
将图片缩放到指定的高度
///
</summary>
///
<param name="imagePath">
源图地址
</param>
///
<param name="savePath">
新图地址
</param>
///
<param name="square">
高度
</param>
///
<returns>
成功true失败false
</returns>
public
bool
CutImageByHeight(
string
imagePath,
string
savePath,
int
square) {
try
{
int
cutHeight
=
square;
System.Drawing.Image objImage
=
System.Drawing.Image.FromFile(imagePath);
float
x
=
objImage.Width;
float
y
=
objImage.Height;
this
.height
=
cutHeight;
this
.width
=
(
int
)((cutHeight
*
x)
/
y);
System.Drawing.Image newimage
=
new
Bitmap(objImage.Width, objImage.Height, PixelFormat.Format32bppRgb);
Graphics g
=
Graphics.FromImage(newimage);
g.DrawImage(objImage,
0
,
0
, objImage.Width, objImage.Height);
g.Dispose();
System.Drawing.Image thumbImage
=
newimage.GetThumbnailImage(
this
.width,
this
.height,
null
, IntPtr.Zero);
thumbImage.Save(savePath, objImage.RawFormat);
objImage.Dispose();
newimage.Dispose();
thumbImage.Dispose();
FileStream fs
=
new
FileStream(savePath, FileMode.Open, FileAccess.Read);
this
.size
=
(
int
)fs.Length;
fs.Close();
return
true
;
}
catch
(Exception ex) {
this
.errMSG
=
ex.ToString();
return
false
;
}
}
///
<summary>
///
将图片剪切到一个正方形
///
</summary>
///
<param name="imagePath">
源图地址
</param>
///
<param name="savePath">
新图地址
</param>
///
<param name="square">
正方形边长
</param>
///
<returns>
成功true失败false
</returns>
public
bool
CutImageSquare(
string
imagePath,
string
savePath,
int
square) {
try
{
this
.width
=
square;
this
.height
=
square;
int
cutWidth
=
square;
int
cutHeight
=
square;
System.Drawing.Image objImage
=
System.Drawing.Image.FromFile(imagePath);
if
(objImage.Width
>=
objImage.Height) {
cutWidth
=
objImage.Height;
cutHeight
=
objImage.Height;
}
else
{
cutWidth
=
objImage.Width;
cutHeight
=
objImage.Width;
}
System.Drawing.Image newimage
=
new
Bitmap(cutWidth, cutHeight, PixelFormat.Format32bppRgb);
Graphics g
=
Graphics.FromImage(newimage);
g.InterpolationMode
=
System.Drawing.Drawing2D.InterpolationMode.High;
g.SmoothingMode
=
System.Drawing.Drawing2D.SmoothingMode.HighQuality;
Rectangle destRect
=
new
Rectangle(
0
,
0
, cutWidth, cutHeight);
Rectangle srcRect
=
new
Rectangle(
0
,
0
, cutWidth, cutHeight);
GraphicsUnit units
=
GraphicsUnit.Pixel;
g.DrawImage(objImage, destRect, srcRect, units);
g.Dispose();
System.Drawing.Image thumbImage
=
newimage.GetThumbnailImage(
this
.width,
this
.height,
null
, IntPtr.Zero);
thumbImage.Save(savePath, objImage.RawFormat);
objImage.Dispose();
newimage.Dispose();
thumbImage.Dispose();
FileStream fs
=
new
FileStream(savePath, FileMode.Open, FileAccess.Read);
this
.size
=
(
int
)fs.Length;
fs.Close();
return
true
;
}
catch
(Exception ex) {
this
.errMSG
=
ex.ToString();
return
false
;
}
}
#region
处理图片长宽显示
public
static
void
GetProperSize(
int
trueWidth,
int
trueHeight,
int
placeWidth,
int
placeHeight,
out
int
showWidth,
out
int
showHeight) {
if
(trueHeight
<
placeHeight
&&
trueWidth
<
placeWidth) {
showHeight
=
trueHeight;
showWidth
=
trueWidth;
}
else
{
float
x
=
(
float
)trueWidth;
float
y
=
(
float
)trueHeight;
float
xPercent
=
x
/
placeWidth;
float
yPercent
=
y
/
placeHeight;
if
(xPercent
<
yPercent) {
showWidth
=
(
int
)((x
*
placeHeight)
/
y);
showHeight
=
placeHeight;
}
else
{
showWidth
=
placeWidth;
showHeight
=
(
int
)((placeWidth
*
y)
/
x);
}
}
}
#endregion
#endregion
}
}