// Occurs when an image has been acquired and is ready to be processed.
private void OnImageGrabbed(Object sender, ImageGrabbedEventArgs e)
{
if (!Dispatcher.CheckAccess())
{
// If called from a different thread, we must use the Invoke method to marshal the call to the proper GUI thread.
// The grab result will be disposed after the event call. Clone the event arguments for marshaling to the GUI thread.
Dispatcher.BeginInvoke(new EventHandler <ImageGrabbedEventArgs>(OnImageGrabbed), sender, e.Clone());
return;
}
try
{
// Acquire the image from the camera. Only show the latest image. The camera may acquire images faster than the images can be displayed.
// Get the grab result.
IGrabResult grabResult = e.GrabResult;
// Check if the image can be displayed.
if (grabResult.IsValid)
{
// Reduce the number of displayed images to a reasonable amount if the camera is acquiring images very fast.
if (!stopWatch.IsRunning || stopWatch.ElapsedMilliseconds > 33)
{
stopWatch.Restart();
Bitmap bitmap = new Bitmap(grabResult.Width, grabResult.Height, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
// Lock the bits of the bitmap.
BitmapData bmpData = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
// Place the pointer to the buffer of the bitmap.
converter.OutputPixelFormat = PixelType.BGRA8packed;
IntPtr ptrBmp = bmpData.Scan0;
converter.Convert(ptrBmp, bmpData.Stride * bitmap.Height, grabResult); //Exception handling TODO
bitmap.UnlockBits(bmpData);
// Assign a temporary variable to dispose the bitmap after assigning the new bitmap to the display control.
//Bitmap bitmapOld = MicroVideo.Image as Bitmap;
// Provide the display control with the new bitmap. This action automatically updates the display.
//MicroVideo.Image = bitmap;
MicroVideo.Source = ImageSourceForBitmap(bitmap);
//if (bitmapOld != null)
//{
// // Dispose the bitmap.
// bitmapOld.Dispose();
//}
}
}
}
catch (Exception exception)
{
ShowException(exception);
}
finally
{
// Dispose the grab result if needed for returning it to the grab loop.
e.DisposeGrabResultIfClone();
}
}
/// <summary>
/// 抓取到图像
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void OnGrabImage(object sender, ImageGrabbedEventArgs e)
{
//线程处理？
if (InvokeRequired)
{
BeginInvoke(new EventHandler <ImageGrabbedEventArgs>(OnGrabImage), sender, e.Clone());
return;
}
try
{
IGrabResult grabResult = e.GrabResult;
if (grabResult.IsValid)
{
if (!myStopWatch.IsRunning || myStopWatch.ElapsedMilliseconds > 33)
{
myStopWatch.Restart();
// 实例化位图对象,图像大小指定为 相机已抓取图象的大小,此处内存未被赋值
myBitmap = new Bitmap(grabResult.Width, grabResult.Height, PixelFormat.Format32bppRgb);
if (copyBitmap == null)
{
copyBitmap = new Bitmap(grabResult.Width, grabResult.Height, PixelFormat.Format32bppRgb);
}
// 使用
BitmapData myBitmapData = myBitmap.LockBits(new Rectangle(0, 0, myBitmap.Width, myBitmap.Height), ImageLockMode.ReadWrite, myBitmap.PixelFormat);
BitmapData copyBitmapData = copyBitmap.LockBits(new Rectangle(0, 0, copyBitmap.Width, copyBitmap.Height), ImageLockMode.ReadWrite, copyBitmap.PixelFormat);
// 设定转换的图像像素格式
converter.OutputPixelFormat = PixelType.BGRA8packed;
// 获取 锁定的图象内存指针
IntPtr ptrBmp = myBitmapData.Scan0;
// 将grabResult中的数据按照指定的内存大小及像素格式转换到ptrBmp所指向(myBitmapData)的内存区域。
converter.Convert(ptrBmp, myBitmapData.Stride * myBitmap.Height, grabResult);
CopyMemory(copyBitmapData.Scan0, myBitmapData.Scan0, myBitmapData.Stride * myBitmap.Height);
copyBitmap.UnlockBits(copyBitmapData);
// 解锁内存
myBitmap.UnlockBits(myBitmapData);
//显示新的图象
//pictureBox.Image = myBitmap;
pictureBox.Invalidate();
}
}
}
catch (Exception E)
{
ShowException(sender, E);
}
finally
{
// Dispose the grab result if needed for returning it to the grab loop.
e.DisposeGrabResultIfClone();
}
}
