c# winform窗口一直置顶显示在桌面最上方或最底层的方法
方法一:调用Windows API来实现窗口置顶。
1.使用命名空间
using System.Runtime.InteropServices;
2、声明Windonws API方法
[DllImport("user32.dll", EntryPoint = "SetWindowPos")] public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags); public const uint SWP_NOMOVE = 0x2; public const uint SWP_NOSIZE = 0x1; public static readonly IntPtr HWND_TOPMOST = new IntPtr(-1); public static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
3、调用方法
SetWindowPos(this.Handle, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);//窗口置顶 SetWindowPos(this.Handle, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);//窗口置底
方法二:使用TopMost属性实现
this.TopMost = true;//窗口置顶 this.TopMost = false;//取消窗口置顶
示例代码
using System; using System.Windows.Forms; using System.Runtime.InteropServices; namespace WindowsFormsApplication1 { public partial class Form1 : Form { [DllImport("user32.dll", EntryPoint = "SetWindowPos")] public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags); public const uint SWP_NOMOVE = 0x2; public const uint SWP_NOSIZE = 0x1; public static readonly IntPtr HWND_TOPMOST = new IntPtr(-1); public static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2); public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { //将窗口置顶 SetWindowPos(this.Handle, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE); } private void button2_Click(object sender, EventArgs e) { //将窗口置底 SetWindowPos(this.Handle, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE); } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { //在窗口关闭时,取消TopMost属性 this.TopMost = false; } } }