c#实现Form窗体始终在桌面最前端显示

方法一：

//调用API

[System.Runtime.InteropServices.DllImport("user32", CharSet = System.Runtime.InteropServices.CharSet.Auto, ExactSpelling = true)]

public static extern IntPtr GetFocus(); //获得本窗体的句柄

[System.Runtime.InteropServices.DllImport("user32", EntryPoint = "SetForegroundWindow")]

public static extern bool SetFocus(IntPtr hWnd);//设置此窗体为活动窗体


// 定义变量,句柄类型

public IntPtr han;

private void Form1_Load(object sender, EventArgs e){

//在窗体加载的时候给变量赋值,即将当前窗体的句柄赋给变量

han = this.Handle;

}
private void timer1_Tick(object sender, EventArgs e){

// 加载一个定时器控件,验证当前WINDOWS句柄是否和本窗体的句柄一样,如果不一样,则激活本窗体

if (han != GetFocus()){

SetFocus(han);

}

this.WindowState = FormWindowState.Normal;

}

c#本来就有Focus()方法，我没用DllImport，试过下面几个方法都不行

control.Activate();
control.TopMost = true;
control.Focus();

方法二：

[System.Runtime.InteropServices.DllImport("user32")]
private static extern IntPtr GetActiveWindow();//获取当前窗体的活动状态

// 判断当前窗口是否处于活动状态的方法

private bool ThisIsActive(){ return (GetActiveWindow() == this.Handle);}

private void timer1_Tick(object sender, EventArgs e){

if (!ThisIsActive()){

this.Activate();

}

this.WindowState = FormWindowState.Normal;

}

方法三：

[DllImport("user32")]    
private    static    extern    IntPtr    FindWindow(string    lpClassName,string    lpWindowName);    
     
[DllImport("user32")]    
private    static    extern    IntPtr    SetParent(IntPtr    hWndChild,    IntPtr    hWndNewParent);    
     
//在窗体On_Load事件中添加（Santos的代码）：    
IntPtr    hDeskTop=FindWindow("Progman",    "Program    Manager");    
SetParent(this.Handle,hDeskTop);

方法四：

[System.Runtime.InteropServices.DllImport("user32.dll")]
static extern bool SetForegroundWindow(IntPtr hWnd);

拓展：

private void Form1_Load(object sender, EventArgs e)
{
    this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;

    this.ShowInTaskbar = false;
    this.TopMost = true;
    this.timer1.Interval = 1;
    this.timer1.Enabled = true;
    this.WindowState = FormWindowState.Maximized;
}

private void timer1_Tick(object sender, EventArgs e)
{
    SetForegroundWindow(this.Handle);
}