Question

我有一些代码, 用于将函数图绘制为 < code> PictureBox 图形。该代码在 < code> paint 事件中执行。在某些时候, 我想将图形内容的位图保存在文件中。

我已经读了"的答案, https://stackoverflow.com/ questions/43051168/ savec-graphics-to-bittmap- outside of-paint", 这个问题 , 却找不到我要找的东西。

我所需要的是同时在 PictureBox (或您建议的任何其他控件) 中画出, 这样在控件隐藏时, 我就不会松绑( 所以我认为我不能 < code> Create Graics () < (/code > ) < em> 和能够将绘图保存在单击按钮的事件中。

我愿意将绘图逻辑从 Paint 事件中删除,如果没有这种逻辑的话。

提前感谢。

Answer 1

我接着根据我的假设回答了问题:

我创建了一个新的 winforms 应用程序

I added a panel and a button I created a Bitmap named buffer, and in the Form1 constructor, initialized it to the size of the panel. Instead of drawing directly to the panel, I draw to the Bitmap, then set the panels background image buffer; This will add persistance to your graphics. If you truly wish to write to a file, I can show you that. Just ask.

要写入文件, 您需要此命名空间引用 :

using System.IO;

我添加了您要求的 < code> Imaage ToDisc 函数。

这是代码:

Bitmap buffer;
public Form1()
{
    InitializeComponent();
    panel1.BorderStyle = BorderStyle.FixedSingle;
    buffer = new Bitmap(panel1.Width,panel1.Height);
}

private void button1_Click(object sender, EventArgs e)
{
    using (Graphics g = Graphics.FromImage(buffer))
    {
        g.DrawRectangle(Pens.Red, 100, 100,100,100);
    }

    panel1.BackgroundImage = buffer;
    //writes the buffer Bitmap to a binary file, only neccessary if you want to save to disc
    ImageToDisc();
    //just to prove that it did write it to file and can be loaded I set the mainforms background image to the file
    this.BackgroundImage=FileToImage();
}

//Converts the image to a byte[] and writes it to disc
public void ImageToDisc()
{
    ImageConverter converter = new ImageConverter();
    File.WriteAllBytes(@"c:	est.dat", (byte[])converter.ConvertTo(buffer, typeof(byte[])));
}

//Converts the image from disc to an image
public Bitmap FileToImage()
{
    ImageConverter converter = new ImageConverter();
    return (Bitmap)converter.ConvertFrom(File.ReadAllBytes(@"c:	est.dat"));
}

友情链接