windows-8 – 如何检测表面键盘是否已连接？

发布时间：2020-12-14 02:50:30 所属栏目：Windows 来源：网络整理

导读：我只有在键盘连接到表面时才需要实现某些功能.有没有办法在连接或移除表面键盘时检测到？我在Surface上试过这段代码： function getKeyboardCapabilities(){ var keyboardCapabilities = new Windows.Devices.Input.KeyboardCapabilities(); console.log(ke

我只有在键盘连接到表面时才需要实现某些功能.有没有办法在连接或移除表面键盘时检测到？

我在Surface上试过这段代码：

function getKeyboardCapabilities()
{   
   var keyboardCapabilities = new Windows.Devices.Input.KeyboardCapabilities();
   console.log(keyboardCapabilities.keyboardPresent);

}

即使未连接键盘,结果也始终为“1”.

解决方法

我使用此代码来识别键盘何时连接到Surface：

var keyboardWatcher = (function () {
    // private
    var keyboardState = false;

    var watcher = Windows.Devices.Enumeration.DeviceInformation.createWatcher();
    watcher.addEventListener("added",function (devUpdate) {
    // GUID_DEVINTERFACE_KEYBOARD
        if ((devUpdate.id.indexOf('{884b96c3-56ef-11d1-bc8c-00a0c91405dd}') != -1) && (devUpdate.id.indexOf('MSHW0007') == -1)    ) {
            if (devUpdate.properties['System.Devices.InterfaceEnabled'] == true) {
                // keyboard is connected 
                keyboardState = true;
            }
        }
    });
    watcher.addEventListener("updated",function (devUpdate) {

        if (devUpdate.id.indexOf('{884b96c3-56ef-11d1-bc8c-00a0c91405dd}') != -1) {
            if (devUpdate.properties['System.Devices.InterfaceEnabled']) {
                // keyboard is connected 
                keyboardState = true;
            }
            else {
                // keyboard disconnected
                keyboardState = false;
            }
        }
    });

    watcher.start();

    // public
    return {
        isAttached: function () {
            return keyboardState;
        }
    }

})();

然后在需要检查键盘状态时调用KeyboardWatcher.isAttached().

（编辑：李大同）

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