Question

我试图找到我以前轻松完成的显示器的分辨率，但是当我尝试在这里使用它时会突然产生：

Exception thrown: 'System.InvalidOperationException' in System.Windows.Forms.dll

Additional information: Cross-thread operation not valid: Control ''
accessed from a thread other than the thread it was created on.

If there is a handler for this exception, the program may be safely continued.

以下是我项目的代码：

public partial class Form1 : Form
{
    //Global Variables/Objects
    int SelectedTool = 1, WindowWidth, WindowHeight; //Here I create the variables 
    bool isMouseDown = false;
    Pen UserPen = new Pen(Color.Black, 10);
    Graphics CanvasGraphics;
    Point LastMousePosition = new Point(0, 0);

    //Initialize Components
    public Form1()
    {
        InitializeComponent();

        //Find Screen Resolution
        WindowWidth = Screen.GetBounds(Form1.ActiveForm).X; //Problem Occurs Here
        WindowHeight = Screen.GetBounds(Form1.ActiveForm).Y; // And Here

            //Set Siz    
            Form1.ActiveForm.MaximumSize = new Size(WindowWidth, WindowHeight);

            //Create Graphics Object
            CanvasGraphics = canvas.CreateGraphics();
            CanvasGraphics.Clear(Color.White);

            //Start Threads
            Painter.RunWorkerAsync();
            Updater.RunWorkerAsync();

            label1.Text = Form1.ActiveForm.Location.X.ToString();
        }

当我更改int WindowWidth＆amp;的值时，会出现问题。 int WindowHeight至Screen.GetBounds(Form1.ActiveForm).X or Y

我也尝试过其他寻找解决方案的方法，但没有办法。我认为我做错了什么导致了这个错误，但问题背后的原因超出了我的范围。

更改后：

private void Form1_SizeChanged(object sender, EventArgs e) //Resize Window
        {
            Form1.ActiveForm.Size = new Size(WindowWidth, WindowHeight); //Doesn't Work
        }
        private void Form1_Activated(object sender, EventArgs e) //Form Activated
        {
        WindowWidth = Screen.FromControl(this).WorkingArea.Size.Width;
        WindowHeight = Screen.FromControl(this).WorkingArea.Size.Height;
        }

Answer 1

在构造函数中，表单尚未显示，因此Form.ActiveForm可能不是您的表单。其次，请使用Screen.WorkingArea，除非您要忽略任务栏等。

protected override void OnShown(EventArgs e)
{
    base.OnShown(e);
    Size resolution = Screen.FromControl(this).WorkingArea.Size;
}

查找屏幕分辨率会创建线程问题

1 个答案: