如何保存在PictureBox上创建的图形? [英] How to save graphics created on a PictureBox?

问题描述

在c#和Visual Studio Windows窗体中，我已将图像加载到图片框(pictureBox2)中，然后将其裁剪并显示在另一个图片框(pictureBox3)中.

In c# and Visual Studio Windows forms I have loaded an image into a picture box (pictureBox2) and then cropped it and show in another picture box (pictureBox3).

现在，我想将pictureBox3内的内容保存为图像文件.

Now I want to save what is inside pictureBox3 as an image file.

我该怎么做?

private void crop_bttn_Click(object sender, EventArgs e)
{
    Image crop = GetCopyImage("grayScale.jpg");
    pictureBox2.Image = crop;

    Bitmap sourceBitmap = new Bitmap(pictureBox2.Image, 
                                     pictureBox2.Width, pictureBox2.Height);
    Graphics g = pictureBox3.CreateGraphics();

    g.DrawImage(sourceBitmap, new Rectangle(0, 0, 
                pictureBox3.Width, pictureBox3.Height), rectCropArea, GraphicsUnit.Pixel);
    sourceBitmap.Dispose();
}

推荐答案

从不使用！ 可以使用Graphics g = Graphics.FromImage(bmp) 或使用e.Graphics参数在控件的Paint事件中使用绘制到Bitmap bmp中.

Never use control.CreateGraphics! Either draw into a Bitmap bmp using a Graphics g = Graphics.FromImage(bmp) or in the Paint event of a control, using the e.Graphics parameter..

这是一个裁剪代码，可绘制到新的位图中，并利用您的控件等，但会更改一些内容:

Here is a cropping code that draws into a new Bitmap and that makes use of your controls etc but changes a few things:

• 它使用从新的Bitmap
创建的Graphics对象
• 它利用using子句来确保它不会泄漏
• 它采用pictureBox3.ClientSize的大小，因此不会包含任何边框.

• It uses a Graphics object that is created from a new Bitmap
• It make use of using clauses to make sure it won't leak
• It takes the size of the pictureBox3.ClientSize so it won't include any borders..

private void crop_bttn_Click(object sender, EventArgs e)
{
    Image crop = GetCopyImage("grayScale.jpg");
    pictureBox2.Image = crop;
    Bitmap targetBitmap = new Bitmap(pictureBox3.ClientSize.Width, 
                                    pictureBox3.ClientSize.Height);
    using (Bitmap sourceBitmap = new Bitmap(pictureBox2.Image, 
                 pictureBox2.ClientSize.Width, pictureBox2.ClientSize.Height))
    {
        using (Graphics g = Graphics.FromImage(targetBitmap))
        {
            g.DrawImage(sourceBitmap, new Rectangle(0, 0, 
                        pictureBox3.ClientSize.Width, pictureBox3.ClientSize.Height), 
                        rectCropArea, GraphicsUnit.Pixel);
        }
    }
    if (pictureBox3.Image != null) pictureBox3.Image.Dispose();
    pictureBox3.Image = targetBitmap;
    targetBitmap.Save(somename, someFormat);
}

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另一种选择是..:

---

The alternative would be to..:

• 将所有代码移至Paint事件
• 将Graphics g = pictureBox3.CreateGraphics();替换为Graphics g = e.Graphics;
• 将这两行插入到click事件中:

• move all your code to the Paint event
• replace the Graphics g = pictureBox3.CreateGraphics(); be Graphics g = e.Graphics;
• insert these two lines to the click event:

Bitmap targetBitmap = new Bitmap(pictureBox3.ClientSize.Width, 
                                pictureBox3.ClientSize.Height);
pictureBox3.DrawToBitmap(targetBitmap, pictureBox3.ClientRectangle);

这篇关于如何保存在PictureBox上创建的图形?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！