Graphics对象的图像文件 [英] Graphics object to image file

问题描述

我想作物和调整图片的大小。这里是我的code：

I would like to crop and resize my image. Here is my code:

Image image = Image.FromFile(AppDomain.CurrentDomain.BaseDirectory + "Cropper/tests/castle.jpg");

// Crop and resize the image.
Rectangle destination = new Rectangle(0, 0, 200, 120);
Graphics graphic = Graphics.FromImage(image);
graphic.DrawImage(image, destination, int.Parse(X1.Value), int.Parse(Y1.Value), int.Parse(Width.Value), int.Parse(Height.Value), GraphicsUnit.Pixel);

现在我认为我得到的裁剪/调整后的图像存储在图形的对象。现在的问题是 - 我怎么把它保存到一个文件

Now I assume that my resulting cropped/resized image is stored in the graphics object. The question is - how do I save it to a file?

推荐答案

这是你获得图形对象 Graphics.FromImage 为图像的图面。所以，你可以简单地将图像保存对象时你做。

The Graphics object that you get from Graphics.FromImage is a drawing surface for the image. So you can simply save the image object when you are done.

string fileName = AppDomain.CurrentDomain.BaseDirectory + "Cropper/tests/castle.jpg");
using (Image image = Image.FromFile(fileName)
{
    using (Graphics graphic = Graphics.FromImage(image))
    {
        // Crop and resize the image.
        Rectangle destination = new Rectangle(0, 0, 200, 120);
        graphic.DrawImage(image, destination, int.Parse(X1.Value), int.Parse(Y1.Value), int.Parse(Width.Value), int.Parse(Height.Value), GraphicsUnit.Pixel);
    }
    image.Save(fileName);
}

但是要注意的JPG图像上反复做这未必是一件好事;图像被重新连接，每次codeD及自JPG采用了破坏性的COM pression的方法，你每次失去一些图像质量。我不会担心，如果这是一个曾经每映像操作虽然。

Beware though that doing this repeatedly on a jpg image may not be a good thing; the image is re-encoded each time and since jpg uses a destructive compression method you will lose some image quality each time. I wouldn't worry about that if this is a once-per-image operation though.

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