问题
ok, I have found many posts on finding a window by name, etc. What I have not found is how to find and switch the window application focus to last active window. The code I am showing below will give me the list of active applications in the task manager that are active.
What I can not figure out how to do is figure out what application was the last active application, and then switch to it. for example...
I have my custom winform application open.
I click a button
My application switches to the last active window / application.
Here is the working code I have so far. (this is the action on a button, and it expects that the application has a textbox named textbox1. you will also need to add using System.Diagnostics;
private void button1_Click(object sender, EventArgs e)
{
Process[] procs = Process.GetProcesses();
IntPtr hWnd;
foreach (Process proc in procs)
{
if ((hWnd = proc.MainWindowHandle) != IntPtr.Zero)
{
textBox1.Text += (proc.ProcessName.ToString());
textBox1.Text += "\t";
textBox1.Text += (hWnd.ToString());
textBox1.Text += "\r\n";
}
}
}
回答1:
Since my comments didn't help you, here's a little resume (didn't test it though):
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool IsWindowVisible(IntPtr hWnd);
[DllImport("user32.dll")]
static extern IntPtr GetLastActivePopup(IntPtr hWnd);
[DllImport("user32.dll", ExactSpelling = true)]
static extern IntPtr GetForegroundWindow();
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
const uint GA_PARENT = 1;
const uint GA_ROOT = 2;
const uint GA_ROOTOWNER = 3;
public IntPtr GetPreviousWindow()
{
IntPtr activeAppWindow = GetForegroundWindow();
if ( activeAppWindow == IntPtr.Zero )
return IntPtr.Zero;
IntPtr prevAppWindow = GetLastActivePopup(activeAppWindow);
return IsWindowVisible(prevAppWindow) ? prevAppWindow : IntPtr.Zero;
}
public void FocusToPreviousWindow()
{
IntPtr prevWindow = GetPreviousWindow();
if ( prevWindow != IntPtr.Zero )
SetForegroundWindow(prevWindow);
}
回答2:
Check this article out: http://www.whitebyte.info/programming/how-to-get-main-window-handle-of-the-last-active-window
Specifically, this code:
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr GetWindow(IntPtr hWnd, uint uCmd);
enum GetWindow_Cmd : uint
{
GW_HWNDFIRST = 0,
GW_HWNDLAST = 1,
GW_HWNDNEXT = 2,
GW_HWNDPREV = 3,
GW_OWNER = 4,
GW_CHILD = 5,
GW_ENABLEDPOPUP = 6
}
[DllImport("user32.dll", ExactSpelling = true, CharSet = CharSet.Auto)]
public static extern IntPtr GetParent(IntPtr hWnd);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
[...]
IntPtr targetHwnd = GetWindow(Process.GetCurrentProcess().MainWindowHandle, (uint)GetWindow_Cmd.GW_HWNDNEXT);
while (true)
{
IntPtr temp = GetParent(targetHwnd);
if (temp.Equals(IntPtr.Zero)) break;
targetHwnd = temp;
}
SetForegroundWindow(targetHwnd);
来源:https://stackoverflow.com/questions/9468476/switch-to-last-active-application-like-alt-tab