C# 在图片框中移动位图

Question

我使用 LockBits 从数组循环创建图像并缩放到 PictureBox.Width * n 和 Height:

using (var bmp = new Bitmap(len, _height, PixelFormat.Format24bppRgb))
{
            var data = bmp.LockBits(new Rectangle(0, 0, len, _height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
            var bytes = data.Stride * data.Height;
            var rgb = new byte[bytes];
            var ptr = data.Scan0;
            Marshal.Copy(data.Scan0, rgb, 0, bytes);


            // …fill array „rgb“

            Marshal.Copy(rgb, 0, ptr, bytes);
            bmp.UnlockBits(data);

            g = _pictureBox.CreateGraphics();
            g.InterpolationMode = InterpolationMode.Default;
            g.DrawImage(bmp, _pictureBox.Width - len * _scaleWidth, 0, len * _scaleWidth, _pictureBox.Height);
}

在下一次迭代中:

Graphics g;
        using (var bmp = new Bitmap(_pictureBox.Image))
        {
            g = _pictureBox.CreateGraphics();
            g.InterpolationMode = InterpolationMode.Default;
            g.DrawImage(_pictureBox.Image, new RectangleF(0, 0, _pictureBox.Width - len * _scaleWidth, _pictureBox.Height), new RectangleF(len * _scaleWidth, 0, _pictureBox.Width * _scaleWidth - len, _height), GraphicsUnit.Pixel);
        }
        g.Dispose();

简而言之:我剪切并复制了会移动图片的部分图像，但没有得到任何东西。是否可能因为上一步的规模？ 也许我错了。建议将新位图移动和添加到末端的算法。

Answer 1

我建议你在 Form 实例上使用 Control.CreateGraphics() 方法，直接在 Form 上写，因为 PaintBox 控件很慢。

尝试使用我的辅助函数，这将允许您使用 Win32 Interop 使用 StretchBlt(拉伸(stretch))或 BitBlt(无拉伸(stretch))粘贴位图的一部分:

示例用法:

Graphics graphics = ...;
graphics.GdiDrawImage
(
    image, 
    new Rectangle(
        (int)rectangle.Left, 
        (int)rectangle.Top, 
        (int)rectangle.Width, 
        (int)rectangle.Height
    ), 
    0, 0, image.Width, image.Height
);

源代码:

public static class GraphicsHelper
{
    public static void GdiDrawImage(this Graphics graphics, Bitmap image, Rectangle rectangleDst, int nXSrc, int nYSrc, int nWidth, int nHeight)
    {
        IntPtr hdc = graphics.GetHdc();
        IntPtr memdc = GdiInterop.CreateCompatibleDC(hdc);
        IntPtr bmp = image.GetHbitmap();
        GdiInterop.SelectObject(memdc, bmp);
        GdiInterop.SetStretchBltMode(hdc, 0x04);
        GdiInterop.StretchBlt(hdc, rectangleDst.Left, rectangleDst.Top, rectangleDst.Width, rectangleDst.Height, memdc, nXSrc, nYSrc, nWidth, nHeight, GdiInterop.TernaryRasterOperations.SRCCOPY);
        //GdiInterop.BitBlt(..) put it here, if you did not mention stretching the source image
        GdiInterop.DeleteObject(bmp);
        GdiInterop.DeleteDC(memdc);
        graphics.ReleaseHdc(hdc);
    }
}

public class GdiInterop
{
    /// <summary>
    /// Enumeration for the raster operations used in BitBlt.
    /// In C++ these are actually #define. But to use these
    /// constants with C#, a new enumeration _type is defined.
    /// </summary>
    public enum TernaryRasterOperations
    {
        SRCCOPY = 0x00CC0020, // dest = source
        SRCPAINT = 0x00EE0086, // dest = source OR dest
        SRCAND = 0x008800C6, // dest = source AND dest
        SRCINVERT = 0x00660046, // dest = source XOR dest
        SRCERASE = 0x00440328, // dest = source AND (NOT dest)
        NOTSRCCOPY = 0x00330008, // dest = (NOT source)
        NOTSRCERASE = 0x001100A6, // dest = (NOT src) AND (NOT dest)
        MERGECOPY = 0x00C000CA, // dest = (source AND pattern)
        MERGEPAINT = 0x00BB0226, // dest = (NOT source) OR dest
        PATCOPY = 0x00F00021, // dest = pattern
        PATPAINT = 0x00FB0A09, // dest = DPSnoo
        PATINVERT = 0x005A0049, // dest = pattern XOR dest
        DSTINVERT = 0x00550009, // dest = (NOT dest)
        BLACKNESS = 0x00000042, // dest = BLACK
        WHITENESS = 0x00FF0062, // dest = WHITE
    };

    /// <summary>
    /// Enumeration to be used for those Win32 function 
    /// that return BOOL
    /// </summary>
    public enum Bool
    {
        False = 0,
        True
    };

    /// <summary>
    /// Sets the background color.
    /// </summary>
    /// <param name="hdc">The HDC.</param>
    /// <param name="crColor">Color of the cr.</param>
    /// <returns></returns>
    [DllImport("gdi32.dll")]
    public static extern int SetBkColor(IntPtr hdc, int crColor);

    /// <summary>
    /// CreateCompatibleDC
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern IntPtr CreateCompatibleDC(IntPtr hDC);

    /// <summary>
    /// DeleteDC
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern Bool DeleteDC(IntPtr hdc);

    /// <summary>
    /// SelectObject
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true)]
    public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);

    /// <summary>
    /// DeleteObject
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern Bool DeleteObject(IntPtr hObject);

    /// <summary>
    /// CreateCompatibleBitmap
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern IntPtr CreateCompatibleBitmap(IntPtr hObject, int width, int height);

    /// <summary>
    /// BitBlt
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern Bool BitBlt(IntPtr hObject, int nXDest, int nYDest, int nWidth, int nHeight, IntPtr hObjSource, int nXSrc, int nYSrc, TernaryRasterOperations dwRop);

    /// <summary>
    /// StretchBlt
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern Bool StretchBlt(IntPtr hObject, int nXOriginDest, int nYOriginDest, int nWidthDest, int nHeightDest, IntPtr hObjSource, int nXOriginSrc, int nYOriginSrc, int nWidthSrc, int nHeightSrc, TernaryRasterOperations dwRop);

    /// <summary>
    /// SetStretchBltMode
    /// </summary>
    [DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
    public static extern Bool SetStretchBltMode(IntPtr hObject, int nStretchMode);
}