C#位图中的内存泄漏

Question

I got a memory leak in my application in this lines.. If i take a look in the task manager, every time when this process is triggered, the RAM memory is increasing by +- 300 MB..

Bitmap bmp1 = new Bitmap(2480, 3508);
panel1.DrawToBitmap(bmp1, new Rectangle(0, 0, 2480, 3508));
pictureBox2.Image = bmp1;

Can someone help me with his leak? If I use:

bmp1.Dispose();

I get an exception in "Program.cs" at this line: Application.Run(new Form1()); And after this, the application is stopped running...

Screen application:

Answer 1

Update: You don't have a memory leak per se , you just have to wait for the Garbage Collector to free up the resources.

If you do want to make the garbage collector collect though, you can do this:

System.GC.Collect();
System.GC.WaitForPendingFinalizers();

---

Why do you need to dispose of the bitmap? If your PictureBox is using it, then you need the bitmap. If you're changing it a lot, maybe you should switch out the old bitmap for a new one and dispose of the old one:

Bitmap bmp1 = new Bitmap(2480, 3508);
panel1.DrawToBitmap(bmp1, new Rectangle(0, 0, 2480, 3508));
Image img = pictureBox1.Image;
pictureBox1.Image = bmp1;
if (img != null) img.Dispose(); // this may be null on the first iteration

Answer 2

I assume you should dispose only the image you don't need anymore . You still need the bmp1 created, you just set it to be the content of the pictureBox2.Image field . Try something along these lines:

Bitmap bmp1 = new Bitmap(2480, 3508);
panel1.DrawToBitmap(bmp1, new Rectangle(0, 0, 2480, 3508));
Bitmap bmp2 = (Bitmap)pictureBox2.Image;
pictureBox2.Image = bmp1;
bmp2.Dispose();

_{Disclaimer: I'm not experienced with C#, so I might be wrong...}

Answer 3

You should use external gdi32.dll for avoiding bitmap memory leaks

[System.Runtime.InteropServices.DllImport("gdi32.dll")] 
public static extern bool DeleteObject(IntPtr hObject);
//your bitmap usage code here
...
//delete bitmap handle when you don't need the bitmap anymore
DeleteObject((IntPtr)hBitmap);

Answer 4

    Bitmap copy_Screen()
    {
        try
        {
            var bmpScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, PixelFormat.Format32bppArgb);
            var gfxScreenshot = Graphics.FromImage(bmpScreenshot);
            try
            {
                gfxScreenshot.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size, CopyPixelOperation.SourceCopy);
            }
            catch (Exception) { }
            return bmpScreenshot;
        }
        catch (Exception) { }
        return new Bitmap(10, 10, PixelFormat.Format32bppArgb);
    }

    private void button5_Click(object sender, EventArgs e)
    {
        //Start Stop timer
        if (timer1.Enabled == false) { timer1.Enabled = true; } else { timer1.Enabled = false; }
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        //memory leak solve
        System.GC.Collect();
        System.GC.WaitForPendingFinalizers();

        Bitmap BM = copy_Screen();
        if (pictureBox1.Image != null)
        {
            pictureBox1.Image.Dispose();
        }
        pictureBox1.Image = BM;

    }