Paint方法抛出System.OutOfMemoryException

本文关键字：System OutOfMemoryException 方法 Paint | 更新日期: 2023-09-27 18:19:05

我有一个艰难的时间试图找出如何防止内存泄漏时，重绘PictureBox

这就是我的绘图方法的样子:

Bitmap image; 
image = new Bitmap((Bitmap)baseImage.Clone());
Graphics g = Graphics.FromImage(image);
//here I'm drawing using created "g"
//reason why am doing it on new bitmap, not on paintBox.Image is that.. 
//..I don't want this drawings to be permanently added to my base image
g.Dispose();
paintBox.Image = image;

然后我使用的方法是改变baseImage和刷新paintBox多次(数百)。调用这个方法给我一个'System '。在System.Drawing.dll中出现OutOfMemoryException这个方法是递归的，但是我很确定它不会导致这个异常，因为当我改变这个方法，只修改基础图像没有刷新油漆盒它工作得很好(但是我想看到它的变化，使最新的)。

那么，在这种情况下，防止内存泄漏的最佳方法是什么?我正在尝试这样做: 
paintBoxx.Image.Dispose();
paintBox.Image = image;

但它给我'系统'。NullReferenceException'(因为我试图使用已处理的图像).

Paint方法抛出System.OutOfMemoryException

修改代码:

Bitmap image; 

image = new Bitmap((Bitmap)baseImage.Clone());
using (Graphics g = Graphics.FromImage(image) )
{
   // I am drawing on the bitmap so I don't permanently change my base image
   // do your draw stuff here..
   g.FillEllipse(Brushes.Yellow, 3, 3, 9, 9);
   // ..  
}
// don't leak the image and..
// ..don't Dispose without checking for null
if (paintBox.Image != null) paintBox.Image.Dispose();
paintBox.Image = image;

注意using子句，即使图纸出现问题，也将处理Graphics对象。

你试过使用MemoryStream吗?

看一下我的示例代码:

image = new Bitmap((Bitmap)baseImage.Clone());
using (MemoryStream imageStream = new MemoryStream())
{
    // put iimagem in memory stream
    image.Save(imageStream, System.Drawing.Imaging.ImageFormat.Gif);
    // create an array of bytes with image length
    byte[] imageContent = new Byte[imageStream.Length];
    // reset memory stream
    imageStream.Position = 0;
    // load array of bytes with the imagem
    imageStream.Read(imageContent, 0, (int)imageStream.Length);
    // change header page "content-type" to "image/jpeg" and print the image.
    Response.ContentType = "image/gif";
    Response.BinaryWrite(imageContent);
}
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