Csharp 如何保存具有多个重叠图片框的图片框

据我所知，您希望绘制类似于流行的编辑应用程序的picture box in layers.我们将制作自己的版本，并将其命名为PictureShop.正如Jimi comments 的那样，您只需要一个PictureBox，当您想要在它上面绘制时，调用它的Refresh方法.它的响应方式是触发Paint消息并提供Graphics画布以供绘制.因此，如果我们将图像放在Layers个位图列表中，我们就可以将层一个接一个地绘制出来.显然，这样做是有问题的，但这是一个开始.

/// <summary>
/// Add layer, then refresh PictureBox to draw.
/// </summary>
private void onButtonDrawClick(object? sender, EventArgs e)
{
    switch ( _clickCount++ ) 
    {
        case 0:
            Layers.Add((Bitmap)Bitmap.FromFile(Path.Combine(ImageFolder, "Image1.png")));
            break;
        case 1:
            Layers.Add((Bitmap)Bitmap.FromFile(Path.Combine(ImageFolder, "Image2.png")));
        break;
    }
    pictureBox1.Refresh();
}

private List<Bitmap> Layers { get; } = new List<Bitmap>();
private void onPicturebox1Paint(object? sender, PaintEventArgs e)
{
    foreach (var bmp in Layers)
    {
        e.Graphics.DrawImage(bmp, pictureBox1.ClientRectangle);
    }
}

如果我们使用的是"其他"应用程序，我们将转到顶层，可能会使用魔杖在顶层图像周围进行 Select ，并使其透明.要使PictureShop执行类似的操作，请在 colored颜色 落在某个值范围内时替换顶部图像中的像素.

现在，公差滑块允许您在保存之前调整数量或透明度.

Transparency method个

private Bitmap replaceColor(Bitmap bmp, Color targetColor, int tolerance)
{
    if(tolerance == 0) return bmp;
    var copy = new Bitmap(bmp);
    for (int x = 0; x < bmp.Width; x++)
    {
        for (int y = 0; y < copy.Height; y++)
        {
            Color pixelColor = copy.GetPixel(x, y);
            if (localIsWithinTolerance(pixelColor, targetColor, tolerance))
            {
                copy.SetPixel(x, y, Color.Transparent);
            }
        }
    }
    bool localIsWithinTolerance(Color pixelColor, Color targetColor, int tolerance)
    {
        return Math.Abs(pixelColor.R - targetColor.R) <= tolerance &&
                Math.Abs(pixelColor.G - targetColor.G) <= tolerance &&
                Math.Abs(pixelColor.B - targetColor.B) <= tolerance;
    }
    return copy;
}

New paint method

private void onPicturebox1Paint(object? sender, PaintEventArgs e)
{
    Bitmap bmp;
    for (int i = 0; i < Layers.Count; i++) 
    {
        switch (i)
        {
            case 0:
                bmp = Layers[i];
                break;
            case 1:
                bmp = replaceColor(Layers[i], Color.FromArgb(0xF0, 0xF0, 0xF0), trackBarTolerance.Value);
                break;
            default:
                return;
        }
        e.Graphics.DrawImage(bmp, pictureBox1.ClientRectangle);
    }
}