GDI32Api、Direct3D屏幕截图

最近因为工作需要，认真研究了一下屏幕截图的方法。

最主要的方法有两种，一、调用windows GDI32 API函数。二、使用DirectX9.0来实现。

另外，光注了一下Microsoft Expression Encoder 4 Screen Capture这个微软新出的功能，Expression　Encoder 4 可实现屏幕录制，录制 文件格式为WMV ，为免费使用版本，Expression Encoder 4 Pro为 收费版本。

还 看了一下基于windows图形驱动技术的屏幕截图方法 ，文章链接地址： http://blog.csdn.net/jia162/article/details/2509974 。实现起来可能比较困难与复杂。没找到实例参考及技术实现的算法，因此也就没有深入研究。

下面两种方法

一、GDI32 API截图，600*480大小生成Bitmap位图大概需要45ms左右，生成位图并save成bmp文件需要大概110ms左右，图片越大，耗费的时间越长，效率比较低。

二、DirectX截图，是把整个屏幕的拷贝到内存里，再进行截取，执行拷贝屏幕的方法g_pd3dDevice->GetFrontBufferData(0, g_pSurface)需要80ms-100ms，效率也比较低。

若那位技术牛人有好滴方法，请推荐一下哦！！！

方法一实现：

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

namespace DataFrameFetch
{
public class WinGdi32Api
{
[DllImport("GDI32.dll")]
public static extern bool BitBlt(int hdcDest, int nXDest, int nYDest, int nWidth, int nHeight, int hdcSrc, int nXSrc, int nYSrc, int dwRop);
[DllImport("GDI32.dll")]
public static extern int CreateCompatibleBitmap(int hdc, int nWidth, int nHeight);
[DllImport("GDI32.dll")]
public static extern int CreateCompatibleDC(int hdc);
[DllImport("GDI32.dll")]
public static extern bool DeleteDC(int hdc);
[DllImport("GDI32.dll")]
public static extern bool DeleteObject(int hObject);
[DllImport("GDI32.dll")]
public static extern int GetDeviceCaps(int hdc, int nIndex);
[DllImport("GDI32.dll")]
public static extern int SelectObject(int hdc, int hgdiobj);
[DllImport("User32.dll")]
public static extern int GetDesktopWindow();
[DllImport("User32.dll")]
public static extern int GetWindowDC(int hWnd);
[DllImport("User32.dll")]
public static extern int GetDC(int hWnd);
[DllImport("User32.dll")]
public static extern int ReleaseDC(int hWnd, int hDC);
}
}

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

namespace DataFrameFetch
{
public class DataFetch
{

public DataFetch()
{ }

///

/// 全屏截图
///

///
public Bitmap CaptureScreen()
{
DateTime dt_start = DateTime.Now;
int source = WinGdi32Api.GetWindowDC(WinGdi32Api.GetDesktopWindow());
int bitmap = WinGdi32Api.CreateCompatibleBitmap(source, WinGdi32Api.GetDeviceCaps(source, 8), WinGdi32Api.GetDeviceCaps(source, 10));

int destination = WinGdi32Api.CreateCompatibleDC(source);
WinGdi32Api.SelectObject(destination, bitmap);
WinGdi32Api.BitBlt(destination, 0, 0, WinGdi32Api.GetDeviceCaps(source, 8), WinGdi32Api.GetDeviceCaps(source, 10), source, 0, 0, 0x00CC0020);
Bitmap img = this.GetBitmap(bitmap);
this.Cleanup(bitmap, source, destination);
DateTime dt_end = DateTime.Now;
TimeSpan ts = dt_end - dt_start;
System.Diagnostics.Debug.WriteLine(ts.Milliseconds.ToString());
return img;
}

public Bitmap CaptureScreen(Control control)
{
DateTime dt_start = DateTime.Now;

int source = WinGdi32Api.GetDC(control.Handle.ToInt32());
int bitmap = WinGdi32Api.CreateCompatibleBitmap(source, control.Width,control.Height);

int destination = WinGdi32Api.CreateCompatibleDC(source);
WinGdi32Api.SelectObject(destination, bitmap);
WinGdi32Api.BitBlt(destination, 0, 0, control.Width, control.Height, source, 0, 0, 0x00CC0020);
Bitmap img = this.GetBitmap(bitmap);
this.Cleanup(bitmap, source, destination);

byte[] buffer = this.ConvertBitmapToRGBByteArray(img);

string filename = "F:\\img\\" + dt_start.ToString("yyyyMMddHHmmss") + dt_start.Millisecond.ToString();

FileStream fs = new FileStream(filename + ".olc", FileMode.Create);
fs.Write(buffer, 0, buffer.Length);
fs.Flush();
fs.Close();

//Bitmap bmp = this.FromRGB(buffer, img.Width, img.Height);
//bmp.Save(filename + "_1.bmp");

DateTime dt_end = DateTime.Now;
TimeSpan ts = dt_end - dt_start;
System.Diagnostics.Debug.WriteLine(ts.Milliseconds.ToString());
return img;
}

private void Cleanup(int bitmap, int source, int destination)
{
WinGdi32Api.ReleaseDC(WinGdi32Api.GetDesktopWindow(), source);
WinGdi32Api.DeleteDC(destination);
WinGdi32Api.DeleteObject(bitmap);
}

private Bitmap GetBitmap(int hbitmap)
{
Bitmap bmp = new Bitmap(Image.FromHbitmap(new IntPtr(hbitmap)), Image.FromHbitmap(new IntPtr(hbitmap)).Width, Image.FromHbitmap(new IntPtr(hbitmap)).Height);
return bmp;
}

///

/// 将位图转换成数组
///

///
///
private byte[] ConvertBitmapToRGBByteArray(Bitmap bmp)
{
Rectangle rect = new Rectangle(new Point(0,0),bmp.Size);
BitmapData bmpdata = bmp.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);

int len = bmp.Width * bmp.Height * 3;
byte[] buffer = new byte[len];
int index = 0;
unsafe
{
byte* color = (byte*)bmpdata.Scan0;
for (int y = 0; y < bmp.Height; y++)
{
for (int x = 0; x < bmp.Width; x++)
{
buffer[index++] = *color;
buffer[index++] = *(color + 1);
buffer[index++] = *(color + 2);
color += 3;
}
//color += bmpdata.Stride - bmpdata.Width * 3;
}
}
bmp.UnlockBits(bmpdata);
return buffer;
}

///

/// 图像象素数组转成位图
///

///
///
///
///
public Bitmap ConvertRGBByteArrayToBitmap(byte[] buffer, int width, int height)
{
// 申请目标位图的变量，并将其内存区域锁定
Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);//创建新图像
Rectangle rect = new Rectangle(0, 0, width, height);
BitmapData bmpData = bmp.LockBits(rect,ImageLockMode.WriteOnly,PixelFormat.Format24bppRgb);
用Marshal的Copy方法，将刚才得到的内存字节数组复制到BitmapData中
Marshal.Copy(buffer, 0, bmpData.Scan0, buffer.Length);
bmp.UnlockBits(bmpData); // 解锁内存区域

return bmp;
}
}
}

方法二以VC++实现

BOOL ScreenShot(HWND hWnd, TCHAR* fileName)
{
HRESULT hr;

IDirect3D9* gpD3D=NULL;
IDirect3DDevice9* gpd3dDevice=NULL;
IDirect3DSurface9* gpSurface=NULL;

D3DDISPLAYMODE ddm;
D3DPRESENT_PARAMETERS d3dpp;

if((gpD3D=Direct3DCreate9(D3D_SDK_VERSION))==NULL)
{
ErrorMessage("Unable to Create Direct3D ");
return E_FAIL;
}

if(FAILED(gpD3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT,&ddm)))
{
ErrorMessage("Unable to Get Adapter Display Mode");
return E_FAIL;
}

ZeroMemory(&d3dpp,sizeof(D3DPRESENT_PARAMETERS));

d3dpp.Windowed=WINDOW_MODE;
d3dpp.Flags=D3DPRESENTFLAG_LOCKABLE_BACKBUFFER;
d3dpp.BackBufferFormat=ddm.Format;
d3dpp.BackBufferHeight=nDisplayHeight=gScreenRect.bottom =ddm.Height;
d3dpp.BackBufferWidth=nDisplayWidth=gScreenRect.right =ddm.Width;
d3dpp.MultiSampleType=D3DMULTISAMPLE_NONE;
d3dpp.SwapEffect=D3DSWAPEFFECT_DISCARD;
d3dpp.hDeviceWindow=hWnd;
d3dpp.PresentationInterval=D3DPRESENT_INTERVAL_DEFAULT;
d3dpp.FullScreen_RefreshRateInHz=D3DPRESENT_RATE_DEFAULT;

if(FAILED(gpD3D->CreateDevice(D3DADAPTER_DEFAULT,D3DDEVTYPE_HAL,hWnd,D3DCREATE_SOFTWARE_VERTEXPROCESSING ,&d3dpp,&gpd3dDevice)))
{
ErrorMessage("Unable to Create Device");
return E_FAIL;
}

if(FAILED(gpd3dDevice->CreateOffscreenPlainSurface(ddm.Width, ddm.Height, D3DFMT_A8R8G8B8, D3DPOOL_SCRATCH, &gpSurface, NULL)))
{
ErrorMessage("Unable to Create Surface");
return E_FAIL;
}
if (FAILED(hr = gpd3dDevice->GetFrontBufferData(0, gpSurface)))
{
gpSurface->Release() ;
return hr ;
}
hr = D3DXSaveSurfaceToFile(fileName, D3DXIFF_BMP, gpSurface, NULL, NULL);
gpSurface->Release() ;

return hr ;
}