Android平台如何打开“前置摄像头”？

更一般地说，如果一台设备有多个嵌入式摄像头， 有没有一种方法可以特别初始化其中一个？

我在Android参考文档中没有找到它：

• https://developer.android.com/reference/android/hardware/Camera.html https://developer.android.com/reference/android/hardware/Camera.html
• https://developer.android.com/reference/android/hardware/camera2/package-summary.html https://developer.android.com/reference/android/hardware/camera2/package-summary.html
• https://developer.android.com/reference/android/hardware/camera2/CameraManager.html https://developer.android.com/reference/android/hardware/camera2/CameraManager.html

三星 SHW-M100S 有两个摄像头。如果没有提到使用两个摄像头，知道三星是怎么做的......？

private Camera openFrontFacingCameraGingerbread() {
    int cameraCount = 0;
    Camera cam = null;
    Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
    cameraCount = Camera.getNumberOfCameras();
    for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
        Camera.getCameraInfo(camIdx, cameraInfo);
        if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
            try {
                cam = Camera.open(camIdx);
            } catch (RuntimeException e) {
                Log.e(TAG, "Camera failed to open: " + e.getLocalizedMessage());
            }
        }
    }

    return cam;
}

添加以下权限AndroidManifest.xml file:

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" android:required="false" />
<uses-feature android:name="android.hardware.camera.front" android:required="false" />

Note:此功能在 Gingerbread(2.3) 及以上 Android 版本中可用。