控制一个表单多次打开

Question

假设我多次打开同一个表单，但我只想控制其中一个（一个 fe 具有“hello”作为窗口标题（文本） <- 来识别）我该如何做到这一点？编辑：这是我想做的一个例子（它有点复杂，我不擅长解释我想要什么）private void openthesecformfirst_Click(object sender, EventArgs e){    Form2 sec = new Form2();    sec.Text = "Hi";    sec.Show();    //The second form is now opened}private void openthesecformsecond_Click(object sender, EventArgs e){    Form2 sec = new Form2();    sec.Text = "Hello";    sec.Show();    //the second form is now opened twice}private void changelabelinfirst_Click(object sender, EventArgs e){    //Identified by the title the first opened form2 is supposed to change a label text    //How do I get this one specifically?}private void changelabelinsecond_Click(object sender, EventArgs e){    //Identified by the title the second opened form2 is supposed to change a label text    //How do I get this one specifically?}

Answer 1

对于 OS Windows 中的查找窗口，您可以使用FindWindowExWin32 Api，例如：

因为这是原始的不安全代码，您应该从 user32.dll 导入函数：

[DllImport("user32.dll", SetLastError = true)] static extern IntPtr 

FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, 

string lpszClass, string lpszWindow);

[DllImport("user32.dll", SetLastError = true)]

public static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr 

childAfter, 

string className,  string windowTitle);

导入后，您可以使用这样的功能：

 var CaptionTextForLooking = "hello"; // or "Hi"

 var foundWindowPtr = 

 FindWindowEx(IntPtr.Zero,IntPtr.Zero,CaptionTextForLooking 

 ,IntPtr.Zero);

Answer 2

您可以使用Application.OpenForms属性。