Question

我目前在将System.Drawing.Bitmap集成到WPF WriteableBitmap时遇到了一些问题。

我想从Bitmap复制到WriteableBitmap的位置（X，Y）。

以下代码显示了我是如何尝试这样做的。

BitmapData Data = Bitmap.LockBits(new Rectangle(0, 0, Bitmap.Width, Bitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
WriteableBitmap.Lock();

//CopyMemory(WriteableBitmap.BackBuffer, Data.Scan0,  ImageBufferSize);

Int32Rect Rect = new Int32Rect(X, Y, Bitmap.Width, Bitmap.Height);
WriteableBitmap.AddDirtyRect(Rect);
Bitmap.UnlockBits(Data);
Bitmap.Dispose();`

非常感谢，

Neokript

Answer 1

使用WritableBitmap.WritePixels。这将阻止使用非托管代码。

BitmapData Data = Bitmap.LockBits(new Rectangle(0, 0, Bitmap.Width, Bitmap.Height),
    ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

try
{    
    WritableBitmap.WritePixels(
        new Int32Rect(0,0,Bitmap.Width, Bitmap.Height),
        Data.Scan0,
        Data.Stride,
        X, Y);
}
finally
{
    Bitmap.UnlockBits(Data);
}

Bitmap.Dispose();

Answer 2

您应该锁定BitmapData和WriteableBitmap。如果要将图像绘制到特定的（x，y）位置，则还应该管理图像的剩余宽度和高度以进行绘制。

[DllImport("kernel32.dll",EntryPoint ="RtlMoveMemory")]
public static extern void CopyMemory(IntPtr dest, IntPtr source,int Length);

public void DrawImage(Bitmap bitmap)
{
    BitmapData data = bitmap.LockBits(new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);

    try
    {
        writeableBitmap.Lock();
        CopyMemory(writeableBitmap.BackBuffer, data.Scan0,
            (writeableBitmap.BackBufferStride * bitmap.Height));
        writeableBitmap.AddDirtyRect(new Int32Rect(0, 0, bitmap.Width, bitmap.Height));
        writeableBitmap.Unlock();
    }
    finally
    {
        bitmap.UnlockBits(data);
        bitmap.Dispose();
    }
}

在您的代码中：

Bitmap bitmap = new Bitmap("pic.jpg"); // obtain it from anywhere, memory, file, stream ,...

writeableBitmap = new WriteableBitmap(
                        bitmap.Width,
                        bitmap.Height,
                        96,
                        96,
                        PixelFormats.Pbgra32,
                        null);

imageBox.Source = writeableBitmap;

DrawImage(bitmap);

我已设法使用此方法渲染具有29 fps的1080P剪辑。

将System.Drawing.Bitmap复制到WriteableBitmap的区域

2 个答案: