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我正在创建一个加载 2 个图像的方法，对它们应用一些转换（缩放/旋转），然后使用 .NET Graphics 类在另一个图像上的某个点绘制它们。

我目前正在尝试的过程如下：

Load bmp1
Load bmp2
Create graphics object from bmp1
Apply tranformations
Save
Repeat process for bmp2
Instantiate new merged bmp obj
Create graphics object from merged bmp
Draw bmp1 & bmp2 on merged bmp
Save

我正在尝试使用以下代码执行此操作：

// load existing bmps
var bmp1 = new Bitmap(Path.Combine(_staticIconsPath, staticIcon.Filename));
var bmp2 = new Bitmap(Path.Combine(_movableIconsPath, movableIcon.Filename));

// apply transforms to bmp1
var canvas1 = Graphics.FromImage(bmp1);
canvas1.ScaleTransform(0.5f, 0.5f);
canvas1.RotateTransform(45.0f);
canvas1.Save();

// apply transforms to bmp2
var canvas2 = Graphics.FromImage(bmp2);
canvas2.ScaleTransform(0.5f, 0.5f);
canvas2.RotateTransform(45.0f);
canvas2.Save();

// create final merged bmp
var mergedBmp = new Bitmap(590, 590);
mergedBmp.SetResolution(bmp1.HorizontalResolution, bmp1.VerticalResolution);

// draw transformed images on to final bmp
var mergedCanvas = Graphics.FromImage(mergedBmp);
mergedCanvas.DrawImage(bmp1, 0, 0);
mergedCanvas.DrawImage(bmp2, 0, 0);

mergedCanvas.Save();

然而，最终结果只是加载了两个原始位图，它们都按预期绘制在彼此之上，但没有应用任何变换。

我以前从未使用过 GDI 或做过任何图像处理，所以我认为我误解了必须遵循的过程的基本内容。任何人都可以帮助我并指出我正确的方向吗？

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2 回答 2

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您必须将名为 canevas 的转换保存在每个转换的 bmp 文件中。在你可以使用那些bmp来绘制你的合并文件之后。但是不要在drawingImage时设置相同的位置，因为同一位置的两个图像你只会看到一个，最后一个。

            // load existing bmps 
        var bmp1 = new Bitmap("test2.bmp");
        var bmp2 = new Bitmap("test2.bmp");

        // apply transforms to bmp1 
        var canvas1 = Graphics.FromImage(bmp1);
        canvas1.ScaleTransform(0.5f, 0.5f);
        canvas1.RotateTransform(45.0f);
        canvas1.Save();
        canvas1.DrawImage(bmp1,100, 0);
        bmp1.Save("test1res.bmp");
        var bmpres1 = new Bitmap("test1res.bmp");

        // apply transforms to bmp2
        var resbmp2 = new Bitmap(1000, 1000);
        var canvas2 = Graphics.FromImage(bmp2);
        canvas2.ScaleTransform(0.5f, 0.5f);
        canvas2.RotateTransform(45.0f);
        canvas2.Save();
        canvas2.DrawImage(bmp2, 100, 0);
        bmp2.Save("test2res.bmp");
        var bmpres2 = new Bitmap("test2res.bmp");

        // create final merged bmp 
        var mergedBmp = new Bitmap(1000, 1000);
        mergedBmp.SetResolution(bmp1.HorizontalResolution, bmp1.VerticalResolution);

        // draw transformed images on to final bmp 
        var mergedCanvas = Graphics.FromImage(mergedBmp);
        mergedCanvas.DrawImage(bmpres1, 0, 0);
        mergedCanvas.DrawImage(bmpres2, 500, 0);

        mergedCanvas.Save();
        Graphics graph = mergedCanvas;
       // Bitmap bmpPicture = new Bitmap("test2.bmp");
        graph.DrawImage(mergedBmp, 0, 0);

        mergedBmp.Save("res.bmp");
于 2012-07-28T10:55:03.150 回答
1

是的，你做错了。除非您实际使用它进行绘图，否则 Graphics 对象的修改不会产生任何影响。你不这样做，你只用 mergeCanvas 绘制。所以重新排序你的代码，类似于这样：

var mergedBmp = new Bitmap(590, 590);
using (var bmp1 = new Bitmap(Path.Combine(_staticIconsPath, staticIcon.Filename)))
using (var bmp2 = new Bitmap(Path.Combine(_movableIconsPath, movableIcon.Filename)))
using (var mergedCanvas = Graphics.FromImage(mergedBmp)) {
    mergedCanvas.Save();
    mergedCanvas.ScaleTransform(0.5f, 0.5f);
    mergedCanvas.DrawImage(bmp1, 0, 0);
    mergedCanvas.Restore();
    mergedCanvas.ScaleTransform(-0.5f, -0.5f);
    mergedCanvas.DrawImage(bmp2, 0, 0);
}

顺便说一句，不要跳过那些using语句，这在位图上非常重要。

于 2012-07-28T12:16:37.647 回答