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 中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control.CreateGraphics！要么在使用Graphics g = Graphics.FromImage(bmp)或绘制到Bitmap bmp>Paint 控件的事件，使用 e.Graphics 参数..

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，它绘制到一个新的位图并使用您的控件等，但更改了一些内容:

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，因此它不会包含任何边框..

• 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);
}

<小时>

另一种选择是......:

---

The alternative would be to..:

• 移动所有代码到Paint事件
• 将Graphics g = pictureBox3.CreateGraphics();替换为Graphics g = e.Graphics;
• 在点击事件中插入这两行:

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！