C# WINFORM 强制让窗体获得焦点(可实现单次置顶或持续置顶)

缺乏、安全感 2022-04-10 08:56 565阅读 0赞

//首先要说明的是与TopMost的效果不同，TopMost是属性定义，而且设置True后，如果不设为Flase则一直置顶，效果很差，

//以下方法解决了TopMost使用上的不足

//调用API  
\[System.Runtime.InteropServices.DllImport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto, ExactSpelling = true)\]  
public static extern IntPtr GetForegroundWindow(); //获得本窗体的句柄  
\[System.Runtime.InteropServices.DllImport("user32.dll", EntryPoint = "SetForegroundWindow")\]  
public static extern bool SetForegroundWindow(IntPtr hWnd);//设置此窗体为活动窗体  
//定义变量,句柄类型  
public IntPtr Handle1;

//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

void Form1\_Load(object sender, EventArgs e)  
\{  
Handle1 = this.Handle;  
timer2.Enabled = true;  
\}

//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

private void timer2\_Tick(object sender, EventArgs e)  
\{  
if (Handle1 != GetForegroundWindow()) //持续使该窗体置为最前,屏蔽该行则单次置顶  
\{  
SetForegroundWindow(Handle1);

//timer2.Stop();//此处可以关掉定时器，则实现单次置顶  
\}  
\}

示例代码：

namespace WinFormsApp_GetForegroundWindowTest

{

public partial class Form1 : Form

{

//调用API

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

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

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

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

//定义变量,句柄类型

public IntPtr Handle1;

Timer timer2 = new Timer();

public Form1()

{

InitializeComponent();

}

Form Form2;

//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

void Form1_Load(object sender, EventArgs e)

{

Handle1 = this.Handle;

timer2.Tick += new EventHandler(timer2_Tick);

timer2.Interval = 1000;

}

//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

private void timer2_Tick(object sender, EventArgs e)

{

//if (Handle1 != GetForegroundWindow()) //持续使该窗体置为最前,屏蔽该行则单次置顶

//{

SetForegroundWindow(Handle1);

timer2.Stop();//此处可以关掉定时器，则实现单次置顶

//}

}

private void btnSetForm2ToTop_Click(object sender, EventArgs e)

{

if (Form2 == null) return;

timer2.Enabled = true;

Handle1 = Form2.Handle;

}

private void btn_OpenForm2_Click(object sender, EventArgs e)

{

Form2 = new Form();

Form2.Text = "Form2";

Form2.Show();

}

[![image][]][image 1]

[image]: /images/20220401/bf76923bcc9d45d6a6874a1b0293cd08.png
[image 1]: https://images0.cnblogs.com/blog/117155/201302/20204040-cd0515aa625b44088a71d61c606469eb.png