C＃处理函数给出错误

Z时代
2024-01-10
分类：问答

我试图每隔10毫秒采取屏幕截图并将它们设置为带有Timer的Picturebox.image。几秒钟的程序运行完美，但几秒钟后程序崩溃。我试图在代码的最后使用Dispose()函数来清除内存，但Dispose函数也给出错误。（定时器的增加区间不工作）C＃处理函数给出错误

using System; 
using System.Collections.Generic; 
using System.ComponentModel; 
using System.Data; 
using System.Drawing; 
using System.Linq; 
using System.Text; 
using System.Threading.Tasks; 
using System.Windows.Forms; 
namespace gameBot 
{ 
    public partial class Form1 : Form 
    { 
     public Form1() 
     { 
      InitializeComponent(); 
     } 
     public Bitmap screenshot; 
     Graphics GFX; 
     private void button1_Click(object sender, EventArgs e) 
     { 
      timer1.enabled = true; 
     } 
     private void timer1_Tick(object sender, EventArgs e) 
     { 
      takescreenshot(); 
     } 
     private void takescreenshot() 
     { 
      screenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
      Screen.PrimaryScreen.Bounds.Height); 
      GFX = Graphics.FromImage(screenshot); 
      GFX.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size); 
      pictureBox1.Image = screenshot; 
      screenshot.Dispose();    
     }   
    } 
}

该错误是

“类型的未处理的异常 'System.ArgumentException' 发生在System.Drawing.dll程序

其他信息：参数无效。“

而且程序崩溃（也许这是崩溃，因为内存溢出异常的？） As you can see in here

回答：

见Graphics.FromImage()：

你应该总是调用Dispose方法以释放FromImage方法创建的图形和相关资源。

此外，没有必要将图形保存在类级别。

考虑到这一点，你需要的是：

public Bitmap screenshot; 
private void takescreenshot() 
{ 
    if (screenshot != null) 
    { 
     screenshot.Dispose(); 
    } 
    screenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height); 
    using (Graphics GFX = Graphics.FromImage(screenshot)) 
    { 
     GFX.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, Screen.PrimaryScreen.Bounds.Size); 
    } 
    pictureBox1.Image = screenshot; 
}

回答：

我建议改变之前，使用太多RAM：

pictureBox1.Image = screenshot; 
screenshot.Dispose();

到：

var oldScreenshot = pictureBox1.Image; 
pictureBox1.Image = screenshot; 
GFX.Dispose(); 
if (oldScreenshot != null) 
    oldScreenshot.Dispose;

，以确保只要您分配一个新的屏幕即可处理旧屏幕截图。

回答：

1）其实你的第一个问题“参数是无效的。”是因为你配置了截图对象。如果您尝试仅运行一次您的takescreenshot（）方法 - 您将会得到此错误。我认为这是因为你将对象“截图”设置为PictureBox1.Image而不是立即处理它。这合乎逻辑！ PictureBox不能渲染处置对象。

2）尝试修改代码的按钮处理这样的：

private Object thisLock = new Object(); 
    private void button1_Click(object sender, EventArgs e) 
    { 
     Thread thr = new Thread(() => 
     { 
      while (true) 
      {pictureBox1.Invoke((Action)(() => 
        { 
         screenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
          Screen.PrimaryScreen.Bounds.Height); 
         GFX = Graphics.FromImage(screenshot); 
         GFX.CopyFromScreen(Screen.PrimaryScreen.Bounds.X, Screen.PrimaryScreen.Bounds.Y, 0, 0, 
          Screen.PrimaryScreen.Bounds.Size); 
         pictureBox1.Image = screenshot; 
        })); 
       } 
       Thread.Sleep(10); 
     }); 
     thr.Start(); 
    }