从 Node-JS 将焦点设置到 Windows 应用程序 [英] Setting focus to a Windows application from Node-JS

问题描述

我有一个在 Windows 上运行的 NodeJS 应用程序，当用户执行某个操作时，它需要显示焦点并将焦点切换到正在运行的 Windows 应用程序.我一直在使用 node-ffi 包进行 Windows API 调用，但无法始终如一地切换焦点.这是我正在使用的代码.它成功获取了正在运行的计算器应用程序的 HWND，但随后尝试将焦点切换到该 HWND 并且仅在某些情况下有效:

I have a NodeJS application running on Windows that needs to display and switch the focus to a running Windows application when a user does a certain action. I have been using the node-ffi package to make windows API calls but have not been able to make it switch focus consistently. Here is the code I am using. It successfully gets the HWND of a running Calculator app, but then tries to switch focus to that HWND and it only works sometimes:

    var ffi = require('ffi');   
    var intPtr = ref.refType('long');
    var user32 = new ffi.Library('user32', {
        'FindWindowA': ['long', [ 'string', 'string']],
        'SetForegroundWindow': ['bool', ['long']],
        'BringWindowToTop': ['bool', ['long']],
    });

    var winToSetOnTop = user32.FindWindowA(null,"calculator")
    var res = user32.ShowWindow(winToSetOnTop, 9);
    res = user32.SetForegroundWindow(winToSetOnTop);
    res = user32.BringWindowToTop(winToSetOnTop);   

这种命令组合在我尝试过的命令中似乎最一致，但它并不总是有效.如果我想切换焦点的窗口被最小化，它总是会弹出到顶部.如果窗口没有最小化，而是在另一个窗口后面，它只会间歇性地显示.我不确定如何始终如一地让正在运行的 Windows 应用程序始终移动到顺序的顶部，即使它当前已最小化.

This combination of commands seems to work most consistently of the ones I have tried, but it does not work all the time. If the window I want to switch focus to is minimized it will always pop to the top. If the window is not minimized, but just behind another window, it will only be shown intermittently. I am not sure how to consistently to get a running windows application to always move to the top of the order, even if it is currently minimized.

推荐答案

我已经制定了以下解决方案，它在所有情况下都能很好地将窗口带到顶部.首先，它将获取正在运行的 Calculator 应用程序实例的窗口句柄，然后将其置于最顶层并聚焦.

I've worked out the following solution which works well in all circumstances to bring a window to the top. First it will get the window handle to a running instance of the Calculator application, then it will bring it topmost and focus it.

var ffi = require('ffi-napi')

var user32 = new ffi.Library('user32', {
    'GetTopWindow': ['long', ['long']],
    'FindWindowA': ['long', ['string', 'string']],
    'SetActiveWindow': ['long', ['long']],
    'SetForegroundWindow': ['bool', ['long']],
    'BringWindowToTop': ['bool', ['long']],
    'ShowWindow': ['bool', ['long', 'int']],
    'SwitchToThisWindow': ['void', ['long', 'bool']],
    'GetForegroundWindow': ['long', []],
    'AttachThreadInput': ['bool', ['int', 'long', 'bool']],
    'GetWindowThreadProcessId': ['int', ['long', 'int']],
    'SetWindowPos': ['bool', ['long', 'long', 'int', 'int', 'int', 'int', 'uint']],
    'SetFocus': ['long', ['long']]
});

var kernel32 = new ffi.Library('Kernel32.dll', {
    'GetCurrentThreadId': ['int', []]
});

var winToSetOnTop = user32.FindWindowA(null, "calculator")
var foregroundHWnd = user32.GetForegroundWindow()
var currentThreadId = kernel32.GetCurrentThreadId()
var windowThreadProcessId = user32.GetWindowThreadProcessId(foregroundHWnd, null)
var showWindow = user32.ShowWindow(winToSetOnTop, 9)
var setWindowPos1 = user32.SetWindowPos(winToSetOnTop, -1, 0, 0, 0, 0, 3)
var setWindowPos2 = user32.SetWindowPos(winToSetOnTop, -2, 0, 0, 0, 0, 3)
var setForegroundWindow = user32.SetForegroundWindow(winToSetOnTop)
var attachThreadInput = user32.AttachThreadInput(windowThreadProcessId, currentThreadId, 0)
var setFocus = user32.SetFocus(winToSetOnTop)
var setActiveWindow = user32.SetActiveWindow(winToSetOnTop)

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