通过API截图后如果释放

[kyogunn]

用avicap32做摄像头视频截图, 以下为部分代码

private const int WM_USER = 0x400;
private const int WS_CHILD = 0x40000000;
private const int WS_VISIBLE = 0x10000000;
private const int WM_CAP_START = WM_USER;
private const int WM_CAP_STOP = WM_CAP_START + 68;
private const int WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10;
private const int WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11;
private const int WM_CAP_SAVEDIB = WM_CAP_START + 25;
private const int WM_CAP_GRAB_FRAME = WM_CAP_START + 60;
private const int WM_CAP_SEQUENCE = WM_CAP_START + 62;
private const int WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20;
private const int WM_CAP_SEQUENCE_NOFILE = WM_CAP_START + 63;
private const int WM_CAP_SET_OVERLAY = WM_CAP_START + 51;
private const int WM_CAP_SET_PREVIEW = WM_CAP_START + 50;
private const int WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START + 6;
private const int WM_CAP_SET_CALLBACK_ERROR = WM_CAP_START + 2;
private const int WM_CAP_SET_CALLBACK_STATUSA = WM_CAP_START + 3;
private const int WM_CAP_SET_CALLBACK_FRAME = WM_CAP_START + 5;
private const int WM_CAP_SET_SCALE = WM_CAP_START + 53;
private const int WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52;
private IntPtr hWndC;
private bool bStat = false;

private IntPtr mControlPtr;
private int mWidth;
private int mHeight;
private int mLeft;
private int mTop;
private string GrabImagePath = "";

/// <summary>
/// 开始显示图像
/// </summary>
public void Start()
{
if (bStat)
return;

bStat = true;
byte[] lpszName = new byte[100];

hWndC = capCreateCaptureWindowA(lpszName, WS_CHILD | WS_VISIBLE, mLeft, mTop, mWidth, mHeight, mControlPtr, 0);

if (hWndC.ToInt32() != 0)
{
SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, 0, 0);
SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, 0, 0);
SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 66, 0);
SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);
SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);
}
return;
}


/// <summary>
/// 抓图
/// </summary>
/// <param name="path">要保存bmp文件的路径</param>
public void GrabImage()
{
IntPtr hBmp = Marshal.StringToHGlobalAnsi(GrabImagePath);
SendMessage(hWndC, WM_CAP_SAVEDIB, 0, hBmp.ToInt32());

}
图片保存以后, 我把图片转存为JPG, 但是生成的bmp无法删除, 请问该如何释放bmp图片, 谢谢

[足球中国]

CloseHandle(hBmp );
也是一个API。

[言多必失]

强制回首非托管代码，

[言多必失]

GC开头。

[kyogunn]

针对我这个情况, 给个代码吧

[Quote=引用 1 楼 的回复:]

强制回首非托管代码，
[/Quote]

[kyogunn]

[Quote=引用 3 楼 的回复:]

CloseHandle(hBmp );
也是一个API。
[/Quote]

提示 "外部组件发生异常"

CloseHandle(hBmp);


[DllImport("kernel32", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
internal static extern int CloseHandle(IntPtr hObject);