使用CGWindowListCopyWindowInfo获取最前面的窗口

Question

在文档中，它说通过这个方法返回的窗口列表：

CFArrayRef windowList = CGWindowListCopyWindowInfo(kCGWindowListOptionOnScreenOnly, kCGNullWindowID);

将按前后顺序返回Windows。但是它没有......最前面的窗口应该是测试，但这里是数组的输出：

2011-03-12 18:18:14.221 test[982:a0f] (
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 22;
            Width = 212;
            X = 1662;
            Y = 0;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 25;
        kCGWindowMemoryUsage = 30104;
        kCGWindowName = "";
        kCGWindowNumber = 14;
        kCGWindowOwnerName = SystemUIServer;
        kCGWindowOwnerPID = 99;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
    },
        {
        kCGWindowAlpha = 0;
        kCGWindowBounds =         {
            Height = 22;
            Width = 1920;
            X = 0;
            Y = 0;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 25;
        kCGWindowMemoryUsage = 5528;
        kCGWindowNumber = 15;
        kCGWindowOwnerName = SystemUIServer;
        kCGWindowOwnerPID = 99;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 22;
            Width = 46;
            X = 1874;
            Y = 0;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 25;
        kCGWindowMemoryUsage = 5528;
        kCGWindowName = "";
        kCGWindowNumber = 12;
        kCGWindowOwnerName = SystemUIServer;
        kCGWindowOwnerPID = 99;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 22;
            Width = 1920;
            X = 0;
            Y = 0;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 24;
        kCGWindowMemoryUsage = 218520;
        kCGWindowName = "Shared Menubar";
        kCGWindowNumber = 6;
        kCGWindowOwnerName = "Window Server";
        kCGWindowOwnerPID = 73;
        kCGWindowSharingState = 2;
        kCGWindowStoreType = 2;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 1058;
            Width = 1920;
            X = 0;
            Y = 22;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 20;
        kCGWindowMemoryUsage = 1200;
        kCGWindowNumber = 13;
        kCGWindowOwnerName = Dock;
        kCGWindowOwnerPID = 98;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 52;
            Width = 676;
            X = 622;
            Y = 1028;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 19;
        kCGWindowMemoryUsage = 157080;
        kCGWindowName = "Magic Mirror";
        kCGWindowNumber = 16;
        kCGWindowOwnerName = Dock;
        kCGWindowOwnerPID = 98;
        kCGWindowSharingState = 2;
        kCGWindowStoreType = 2;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 382;
            Width = 480;
            X = 335;
            Y = 367;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 792496;
        kCGWindowName = test;
        kCGWindowNumber = 252;
        kCGWindowOwnerName = test;
        kCGWindowOwnerPID = 982;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 807;
            Width = 1206;
            X = 321;
            Y = 157;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 4055280;
        kCGWindowName = "AppDelegate.m - test";
        kCGWindowNumber = 24;
        kCGWindowOwnerName = Xcode;
        kCGWindowOwnerPID = 132;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 967;
            Width = 960;
            X = 175;
            Y = 22;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 3817968;
        kCGWindowName = "test - Debugger Console";
        kCGWindowNumber = 31;
        kCGWindowOwnerName = Xcode;
        kCGWindowOwnerPID = 132;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 967;
            Width = 1845;
            X = 121;
            Y = 22;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 882288;
        kCGWindowName = "CocoaDev Forums - get focused window id";
        kCGWindowNumber = 80;
        kCGWindowOwnerName = "Google Chrome";
        kCGWindowOwnerPID = 244;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 784;
            Width = 885;
            X = 560;
            Y = 157;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 318768;
        kCGWindowName = "Console Messages";
        kCGWindowNumber = 125;
        kCGWindowOwnerName = Console;
        kCGWindowOwnerPID = 482;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 494;
            Width = 1167;
            X = 519;
            Y = 417;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 2441264;
        kCGWindowName = Debug;
        kCGWindowNumber = 54;
        kCGWindowOwnerName = Finder;
        kCGWindowOwnerPID = 100;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 382;
            Width = 480;
            X = 335;
            Y = 367;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 55216;
        kCGWindowName = test;
        kCGWindowNumber = 223;
        kCGWindowOwnerName = test;
        kCGWindowOwnerPID = 849;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 437;
            Width = 770;
            X = 396;
            Y = 308;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 238512;
        kCGWindowName = Applications;
        kCGWindowNumber = 19;
        kCGWindowOwnerName = Finder;
        kCGWindowOwnerPID = 100;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 437;
            Width = 770;
            X = 450;
            Y = 429;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = 0;
        kCGWindowMemoryUsage = 332720;
        kCGWindowName = Applications;
        kCGWindowNumber = 17;
        kCGWindowOwnerName = Finder;
        kCGWindowOwnerPID = 100;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
        kCGWindowWorkspace = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 14;
            Width = 1920;
            X = 0;
            Y = 22;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = "-20";
        kCGWindowMemoryUsage = 5528;
        kCGWindowName = "Backstop Menubar";
        kCGWindowNumber = 11;
        kCGWindowOwnerName = "Window Server";
        kCGWindowOwnerPID = 73;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 2;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 1080;
            Width = 1920;
            X = 0;
            Y = 0;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = "-2147483627";
        kCGWindowMemoryUsage = 1200;
        kCGWindowName = "";
        kCGWindowNumber = 10;
        kCGWindowOwnerName = Finder;
        kCGWindowOwnerPID = 100;
        kCGWindowSharingState = 1;
        kCGWindowStoreType = 1;
    },
        {
        kCGWindowAlpha = 1;
        kCGWindowBounds =         {
            Height = 1080;
            Width = 1920;
            X = 0;
            Y = 0;
        };
        kCGWindowIsOnscreen = 1;
        kCGWindowLayer = "-2147483628";
        kCGWindowMemoryUsage = 8328600;
        kCGWindowName = Desktop;
        kCGWindowNumber = 2;
        kCGWindowOwnerName = "Window Server";
        kCGWindowOwnerPID = 73;
        kCGWindowSharingState = 2;
        kCGWindowStoreType = 2;
    }
)

SystemUIServer、dock和magic mirror是什么？它们不是我最前面的应用程序。谢谢！

- user635064

Answer 1

获取苹果的示例应用程序：Son Of Grab。然后构建和运行它，您将获得一个非常方便的交互式应用程序，用于调查窗口服务器中已知的所有窗口。

答案是窗口按从前到后的顺序排序，但定义为窗口的用户界面元素要远远多于您所期望的。这包括菜单栏、Dock、服务菜单、桌面等。这些是在不同级别上定义的，对应于kCGWindowLayer在您的输出中。

您想要第一个定义为标准窗口级别（零）的窗口。如果您查看输出，具有kCGWindowLayer == 0的第一个窗口实际上是第7个。

- skue

Answer 2

SystemUIServer 是顶部菜单栏。Dock 是 Dock（通常在屏幕底部）。我不熟悉“Magic Mirror”。您可以使用 lsregister 在系统上查找它：

`locate lsregister` -dump

在输出中搜索“魔镜”。

- Rob Napier

---

谢谢您的输入。但是我怎么才能获取用户可以看到的最前面的窗口呢？我显然无法看到SystemUIServer，并且对于用户来说，最前面的窗口被命名为“test”。那么我该怎么办才能获取它呢？在我提供的列表中，它排名第7。 - user635064