如何使自定义标题栏上的无边框表单可拖动？

Question

我已经使用 c# 创建了一个 border-less 表单，但可以使自定义标题栏可移动，所以我在互联网上搜索并找到了这段代码：

protected override void WndProc(ref Message m)
{ 
    base.WndProc(ref m);
    if (m.Msg == WM_NCHITTEST)
       m.Result = (IntPtr)(HT_CAPTION);
}

private const int WM_NCHITTEST = 0x84;
private const int HT_CLIENT = 0x1;
private const int HT_CAPTION = 0x2;

应用此代码后，可以在除标题栏外的每一寸窗体中单击并拖动我的窗体。

Answer 1

这是可移动标题栏的一个很好的例子。
这是一个完整的例子

using System;
using System.Drawing;
using System.Windows.Forms;

namespace Custom_Title_Bar
{
public partial class MainForm : Form
{
    private PictureBox title = new PictureBox(); // create a PictureBox
    private Label minimise = new Label(); // this doesn't even have to be a label!
    private Label maximise = new Label(); // this will simulate our this.maximise box
    private Label close = new Label(); // simulates the this.close box

    private bool drag = false; // determine if we should be moving the form
    private Point startPoint = new Point(0, 0); // also for the moving

    public MainForm()
    {
        this.FormBorderStyle = FormBorderStyle.None; // get rid of the standard title bar

        this.title.Location = this.Location; // assign the location to the form location
        this.title.Width = this.Width; // make it the same width as the form
        this.title.Height = 50; // give it a default height (you may want it taller/shorter)
        this.title.BackColor = Color.Black; // give it a default colour (or load an image)
        this.Controls.Add(this.title); // add it to the form's controls, so it gets displayed
        // if you have an image to display, you can load it, instead of assigning a bg colour
        // this.title.Image = new Bitmap(System.Environment.CurrentDirectory + "\title.jpg");
        // if you displayed an image, alter the SizeMode to get it to display as you want it to
        // examples:
        // this.title.SizeMode = PictureBoxSizeMode.StretchImage;
        // this.title.SizeMode = PictureBoxSizeMode.CenterImage;
        // this.title.SizeMode = PictureBoxSizeMode.Zoom;
        // etc          

        // you may want to use PictureBoxes and display images
        // or use buttons, there are many alternatives. This is a mere example.
        this.minimise.Text = "Minimise"; // Doesn't have to be
        this.minimise.Location = new Point(this.Location.X+5, this.Location.Y+5); // give it a default location
        this.minimise.ForeColor = Color.Red; // Give it a colour that will make it stand out
        // this is why I didn't use an image, just to keep things simple:
        this.minimise.BackColor = Color.Black; // make it the same as the PictureBox
        this.Controls.Add(this.minimise); // add it to the form's controls
        this.minimise.BringToFront(); // bring it to the front, to display it above the picture box

        this.maximise.Text = "Maximise";
        // remember to make sure it's far enough away so as not to overlap our minimise option
        this.maximise.Location = new Point(this.Location.X+60, this.Location.Y+5);
        this.maximise.ForeColor = Color.Red;
        this.maximise.BackColor = Color.Black; // remember, we want it to match the background
        this.maximise.Width = 50;
        this.Controls.Add(this.maximise); // add it to the form
        this.maximise.BringToFront();

        this.close.Text = "Close";
        this.close.Location = new Point(this.Location.X+120, this.Location.Y+5);
        this.close.ForeColor = Color.Red;
        this.close.BackColor = Color.Black;
        this.close.Width = 37; // this is just to make it fit nicely
        this.Controls.Add(this.close);
        this.close.BringToFront();

        // now we need to add some functionality. First off, let's give those labels
        // MouseHover and MouseLeave events, so they change colour
        // Since they're all going to change to the same colour, we can give them the same
        // event handler, which saves time of writing out all those extra functions
        this.minimise.MouseEnter += new EventHandler(Control_MouseEnter);
        this.maximise.MouseEnter += new EventHandler(Control_MouseEnter);
        this.close.MouseEnter += new EventHandler(Control_MouseEnter);

        // and we need to do the same for MouseLeave events, to change it back
        this.minimise.MouseLeave += new EventHandler(Control_MouseLeave);
        this.maximise.MouseLeave += new EventHandler(Control_MouseLeave);
        this.close.MouseLeave += new EventHandler(Control_MouseLeave);

        // and lastly, for these controls, we need to add some functionality
        this.minimise.MouseClick += new MouseEventHandler(Control_MouseClick);
        this.maximise.MouseClick += new MouseEventHandler(Control_MouseClick);
        this.close.MouseClick += new MouseEventHandler(Control_MouseClick);

        // finally, wouldn't it be nice to get some moveability on this control?
        this.title.MouseDown += new MouseEventHandler(Title_MouseDown);
        this.title.MouseUp += new MouseEventHandler(Title_MouseUp);
        this.title.MouseMove += new MouseEventHandler(Title_MouseMove);         
    }

    private void Control_MouseEnter(object sender, EventArgs e)
    {
        if (sender.Equals(this.close))
            this.close.ForeColor = Color.White;
        else if (sender.Equals(this.maximise))
            this.maximise.ForeColor = Color.White;
        else // it's the minimise label
            this.minimise.ForeColor = Color.White;              
    }

    private void Control_MouseLeave(object sender, EventArgs e)
    { // return them to their default colours
        if (sender.Equals(this.close))
            this.close.ForeColor = Color.Red;
        else if (sender.Equals(this.maximise))
            this.maximise.ForeColor = Color.Red;
        else // it's the minimise label
            this.minimise.ForeColor = Color.Red;    
    }

    private void Control_MouseClick(object sender, MouseEventArgs e)
    {
        if (sender.Equals(this.close))
            this.Close(); // close the form
        else if (sender.Equals(this.maximise))
        { // maximise is more interesting. We need to give it different functionality,
          // depending on the window state (Maximise/Restore)
            if (this.maximise.Text == "Maximise")
            {
                this.WindowState = FormWindowState.Maximized; // maximise the form
                this.maximise.Text = "Restore"; // change the text
                this.title.Width = this.Width; // stretch the title bar
            }
            else // we need to restore
            { 
                this.WindowState = FormWindowState.Normal;
                this.maximise.Text = "Maximise";
            }
        }
        else // it's the minimise label
            this.WindowState = FormWindowState.Minimized; // minimise the form
    }

    void Title_MouseUp(object sender, MouseEventArgs e)
    {
        this.drag = false;
    }

    void Title_MouseDown(object sender, MouseEventArgs e)
    {
        this.startPoint = e.Location;
        this.drag = true;
    }

    void Title_MouseMove(object sender, MouseEventArgs e)
    {
        if (this.drag) 
        { // if we should be dragging it, we need to figure out some movement
            Point p1 = new Point(e.X, e.Y);
            Point p2 = this.PointToScreen(p1);
            Point p3 = new Point(p2.X - this.startPoint.X, 
                                 p2.Y - this.startPoint.Y);
            this.Location = p3;
        }
    }
}   // end of the class
}   // end of the namespace

如果你想的话你可以只提取移动代码并将其与你的代码集成，移动标题代码就在下面事件处理程序

• Title_MouseUp

• Title_MouseDown

• Title_MouseMove

这是这段代码的原文，你可以阅读它以获得更多关于代码的解释
http://www.dreamincode.net/forums/topic/64981-designing-a-custom-title-bar/