在表面视图中打开前置摄像头

Question

我收到异常 java.lang.RuntimeException: Fail to get camera info 在 Camera.getCameraInfo(cameraId,info);

我的代码是：

public void surfaceCreated(SurfaceHolder holder) {
    int cameraId = -1;
    for(int i=0;i<Camera.getNumberOfCameras();i++){
        Camera.CameraInfo info = new Camera.CameraInfo();
        Camera.getCameraInfo(cameraId,info);
        if(info.facing== Camera.CameraInfo.CAMERA_FACING_FRONT){
            cameraId = i;
            break;
        }
    }
    camera = Camera.open(cameraId);
}

和清单还有：

<uses-permission android:name="android.permission.CAMERA" />

<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.front" />
<uses-feature android:name="android.hardware.camera.autofocus" />

缺少什么东西，我该如何解决？欢迎任何帮助。

Answer 1

您遇到异常是因为您将 cameraId 初始化为 -1，这是错误的。并传递它以获取相机信息

Camera.getCameraInfo(cameraId,info);

将 cameraId 初始化为 0 以消除异常。

Answer 2

我改变了方法；之前我正在实施 SurfaceHolder.Callback 但现在我创建了它的对象。

我将代码从 SurfaceCreated 移到了 onResume()

public void onResume() {
    super.onResume();
    for(int i=0;i<Camera.getNumberOfCameras();i++){
        Camera.CameraInfo info = new Camera.CameraInfo();
        Camera.getCameraInfo(i,info);
        if(info.facing== Camera.CameraInfo.CAMERA_FACING_FRONT){
            cameraId = i;
            break;
        }
    }
    camera=Camera.open(cameraId);
    camera.startPreview();
}

回调的对象是这样的：

SurfaceHolder.Callback surfaceCallback=new SurfaceHolder.Callback() {
    public void surfaceCreated(SurfaceHolder holder) {
        // no-op -- wait until surfaceChanged()

    }
    public void surfaceChanged(SurfaceHolder holder,
                               int format, int width,
                               int height) {
        Camera.Parameters parameters=camera.getParameters();
        Camera.Size size=getBestPreviewSize(width, height,
                    parameters);
        Display display = ((WindowManager)getSystemService(WINDOW_SERVICE)).getDefaultDisplay();

        if (size!=null) {
            parameters.setPreviewSize(size.width, size.height);
            camera.setParameters(parameters);
            camera.setDisplayOrientation(90);
            cameraConfigured=true;
        }
        camera.startPreview();
    }
    public void surfaceDestroyed(SurfaceHolder holder) {
        // no-op
    }
};

这解决了我的问题。

Answer 3

此方法将return前置摄像头ID：

private int getFrontCameraId(){
            int camId = -1;
            int numberOfCameras = Camera.getNumberOfCameras();
            Camera.CameraInfo ci = new Camera.CameraInfo();

            for(int i = 0;i < numberOfCameras;i++){
                Camera.getCameraInfo(i,ci);
                if(ci.facing == Camera.CameraInfo.CAMERA_FACING_FRONT){
                    camId = i;
                }
            }

            return camId;
        }

在此处传递此 ID：camera=Camera.open(getFrontCameraId());

在表面视图中打开前置摄像头

Open the Front camera in a surface view

java

camera

android