Question

我有这个代码，它使表单始终在顶部，透明并点击。

    using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    using System.Diagnostics;
    using System.Runtime.InteropServices;

    namespace HyperBox
    {

public partial class Form1 : Form
{

    public Form1()
    {
        InitializeComponent();

        this.TopMost = true; // make the form always on top
        this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None; // hidden border
        this.WindowState = FormWindowState.Maximized; // maximized
        this.MinimizeBox = this.MaximizeBox = false; // not allowed to be minimized
        this.MinimumSize = this.MaximumSize = this.Size; // not allowed to be resized
        this.TransparencyKey = this.BackColor = Color.Red; // the color key to transparent, choose a color that you don't use

        // Set the form click-through
        int initialStyle = GetWindowLong(this.Handle, -20);
        SetWindowLong(this.Handle, -20, initialStyle | 0x80000 | 0x20);
    }

    [System.Runtime.InteropServices.DllImport("user32.dll", SetLastError = true)]
    static extern int GetWindowLong(IntPtr hWnd, int nIndex);





    [System.Runtime.InteropServices.DllImport("user32.dll")]
    static extern int SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);


    [System.Runtime.InteropServices.DllImport("user32.dll")]
    static extern bool SetLayeredWindowAttributes(IntPtr hwnd, uint crKey, byte bAlpha, uint dwFlags);


    [System.Runtime.InteropServices.DllImport("user32.dll")]
    static extern int SetParent(int hWndChild, int hWndNewParent);


    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    public static extern IntPtr FindWindow(
     [MarshalAs(UnmanagedType.LPTStr)] string lpClassName,
     [MarshalAs(UnmanagedType.LPTStr)] string lpWindowName);
    [DllImport("user32.dll")]
    public static extern IntPtr SetParent(
     IntPtr hWndChild,      // handle to window
     IntPtr hWndNewParent   // new parent window
     );

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        // draw what you want
        e.Graphics.FillRectangle(Brushes.Red, new Rectangle((SystemInformation.WorkingArea.Width / 2) - 4, (SystemInformation.WorkingArea.Height / 2) - 20, 8, 40));
        e.Graphics.FillRectangle(Brushes.Red, new Rectangle((SystemInformation.WorkingArea.Width / 2) - 20, (SystemInformation.WorkingArea.Height / 2) - 4, 40, 8));


    }
    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {

    }

    private void Form1_Paint(object sender, PaintEventArgs e)
    {

    }

    private void Form1_Load(object sender, EventArgs e)
    {

        IntPtr hwndf = this.Handle;
        IntPtr hwndParent = FindWindow("chrome.exe", null);
        SetParent(hwndf, hwndParent);



    }

}
    }

问题是当我绘制图形时，它什么都没画。当坐标在100左右时就可以了。但是当它完成上述方法时，没有任何反应。完全没有像素。有人可以解释为什么会发生这种情况并重新发布一个固定的片段，谢谢。莱恩

Answer 1

OnPaint为您的表单提供图形对象，而不是屏幕。您正在根据系统的工作区域填充矩形，而不是表单。您需要调整矩形坐标并将表单放在您希望图形显示的位置。位置为(0, 0)的矩形是表单客户区的左上角。您还应该能够通过调用基本Form类上公开的ClientRectangle来访问该矩形。

请查看此问题，以便在表单外绘图：Draw / Paint Outside Form 如果您不想在表单上绘画，那么这应该让您从正确的方向开始，但根据需要重新定位和调整表单可能会更容易。

编辑在调试问题时至少添加某种边框可能是明智之举。这将帮助您查看表单的位置以及表单所在的监视器。然后，您可以在OnPaint中断点检查您的数字，以确保正确创建矩形，但是，确保您在表单的客户区域内绘画应解决您的问题。

绘图图形不起作用

1 个答案: