恢复另一个应用程序的最小化窗口

问题描述

我正在向一个应用程序添加一些代码，如果该应用程序尚未运行，则该应用程序将启动另一个应用程序，或者如果已运行，则将其置于最前面.这需要少量的互操作/WinAPI 代码，我已经从其他站点获得了这些示例，但似乎无法在 Win7 中工作.

I'm adding some code to an app that will launch another app if it isn't already running, or if it is, bring it to the front. This requires a small amount of interop/WinAPI code, which I've gotten examples for from other sites but can't seem to get to work in Win7.

如果窗口处于某种可见状态，则 API 的 SetForegroundWindow 方法就像一种处理方式(这将是主要情况，根据公司政策，如果外部应用程序正在运行，则不应将其最小化).但是，如果它被最小化(例外但很重要，因为在这种情况下我的应用程序似乎什么都不做)，无论是这个方法还是 ShowWindow/ShowWindowAsync 实际上都不会从任务栏恢复窗口；所有方法都只是突出显示任务栏按钮.

If the window is in some visible state, then the API's SetForegroundWindow method works like a treat (and this would be the main case, as per company policy if the external app is running it should not be minimized). However, if it is minimized (exceptional but important as my app will appear to do nothing in this case), neither this method nor ShowWindow/ShowWindowAsync will actually bring the window back up from the taskbar; all of the methods simply highlight the taskbar button.

这是代码；大部分工作都很好，但是无论我发送什么命令，对 ShowWindow() 的调用(我也试过 ShowWindowAsync)从来没有做我想要的:

Here's the code; most of it works just fine, but the call to ShowWindow() (I've also tried ShowWindowAsync) just never does what I want it to no matter what the command I send is:

[DllImport("user32.dll")]
    private static extern int SetForegroundWindow(IntPtr hWnd);

    private const int SW_SHOWNORMAL = 1;
    private const int SW_SHOWMAXIMIZED = 3;
    private const int SW_RESTORE = 9;

    [DllImport("user32.dll")]
    private static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

...

//The app is named uniquely enough that it can't be anything else,
//and is not normally launched except by this one.
//so this should normally return zero or one instance
var processes = Process.GetProcessesByName("ExternalApp.exe");

        if (processes.Any()) //a copy is already running
        {
            //I can't currently tell the window's state,
            //so I both restore and activate it
            var handle = processes.First().MainWindowHandle;
            ShowWindow(handle, SW_RESTORE); //GRR!!!
            SetForegroundWindow(handle);
            return true;
        }

        try
        {
            //If a copy is not running, start one.
            Process.Start(@"C:Program Files (x86)ExternalAppExternalApp.exe");
            return true;
        }
        catch (Exception)
        {
            //fallback for 32-bit OSes
            Process.Start(@"C:Program FilesExternalAppExternalApp.exe");
            return true;
        }

我尝试了 SHOWNORMAL (1)、SHOWMAXIMIZED (3)、RESTORE (9) 和其他几个大小调整命令，但似乎没有任何效果.想法?

I've tried SHOWNORMAL (1), SHOWMAXIMIZED (3), RESTORE (9), and a couple other sizing commands, but nothing seems to do the trick. Thoughts?

我发现一些我认为可以工作的其他代码存在问题.对 GetProcessesByName() 的调用没有找到进程，因为我正在寻找可执行文件名称，这不是进程名称.这导致我认为正在运行的代码实际上根本没有执行.我认为它是有效的，因为外部应用程序显然也会检测到一个副本已经在运行并尝试激活该当前实例.我从我搜索的进程名称中删除了.exe"，现在代码执行了；然而，这似乎是倒退了一步，因为现在当我调用 ShowWindow[Async] 时，任务栏按钮甚至没有突出显示.所以，我现在知道我的应用程序和我正在调用的外部应用程序都不能在 Win7 中以编程方式更改不同实例的窗口状态.这是怎么回事?

I found an issue with some of the other code I had thought was working. The call to GetProcessesByName() was not finding the process because I was looking for the executable name, which was not the process name. That caused the code I thought was running and failing to actually not execute at all. I thought it was working because the external app will apparently also detect that a copy is already running and try to activate that current instance. I dropped the ".exe" from the process name I search for and now the code executes; however that seems to be a step backwards, as now the taskbar button isn't even highlighted when I call ShowWindow[Async]. So, I now know that neither my app, nor the external app I'm invoking, can change the window state of a different instance programmatically in Win7. What's goin' on here?

推荐答案

... 显然你不能相信进程给你的信息.

... Apparently you cannot trust the information a Process gives you.

Process.MainWindowHandle 返回应用程序创建的第一个窗口的窗口句柄，通常是该应用程序的主顶级窗口.但是，在我的情况下，对 FindWindow() 的调用表明我想要恢复的实际窗口的句柄不是 MainWindowHandle 所指向的.在这种情况下，来自 Process 的窗口句柄似乎是程序加载主窗体时显示的初始屏幕的句柄.

Process.MainWindowHandle returns the window handle of the first window created by the application, which is USUALLY that app's main top-level window. However, in my case, a call to FindWindow() shows that the handle of the actual window I want to restore is not what MainWindowHandle is pointing to. It appears that the window handle from the Process, in this case, is that of the splash screen shown as the program loads the main form.

如果我在 FindWindow 返回的句柄上调用 ShowWindow，它会完美运行.

If I call ShowWindow on the handle that FindWindow returned, it works perfectly.

更不寻常的是，当窗口打开时，调用 SetForegroundWindow()，当给定进程的 MainWindowHandle(它应该是无效的，因为该窗口已关闭)，工作正常.很明显，该句柄具有一定的有效性，只是在窗口最小化时无效.

What's even more unusual is that when the window's open, the call to SetForegroundWindow(), when given the process's MainWindowHandle (which should be invalid as that window has closed), works fine. So obviously that handle has SOME validity, just not when the window's minimized.

总而言之，如果您发现自己陷入困境，请调用 FindWindow，将您的外部应用程序主窗口的已知名称传递给它，以获得您需要的句柄.

In summary, if you find yourself in my predicament, call FindWindow, passing it the known name of your external app's main window, to get the handle you need.

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