如何为前置摄像头添加开关按钮？

Question

在添加按钮或 ImageView 方面需要帮助，以便我可以切换到前置摄像头，请帮助！！！ 任何人都可以帮助我并快速尝试添加它，但我一直在切换相机上收到错误。我尝试实现一个独立于前置摄像头的类的意图，但是当切换回后置摄像头时，屏幕将保持黑色。如果有人可以提供帮助，我想以正确的方式实现前置摄像头，谢谢。如果可以的话，请将前置摄像头源代码添加到我的项目中，谢谢。

ImageView cameraFront;

private int width, height;

private int sdkVersion;

private int timeCount = 0;

private int PORTRAIT = 0;

private int PORTRAIT_REV = 1;

private int LANDSCAPE_RIGHT = 2;

private int LANDSCAPE_LEFT = 3;

private SurfaceView surface;

private SurfaceHolder surfaceHolder;

private MediaRecorder videoRecorder;

private Button recordBtn;

private TextView timeView;

private String videoPath;

private Timer autoStopTimer;

private Camera mCamera;

private Camera.Parameters parameters;

private List<Size> supportedSizes = null;

private SensorManager sensorManager = null;

private boolean isRecording = false;

boolean changeOrientation = false;

int mDetected_Orientention = 0;

Tosty toast;




@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    try {

        sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

        sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_GAME);

        setContentView(R.layout.video_recorder);

        videoPath = getIntent().getStringExtra("videoPath");

        width = getIntent().getIntExtra("Width", 320);

        height = getIntent().getIntExtra("Height", 240);

        WindowManager mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);

        Display mDisplay = mWindowManager.getDefaultDisplay();

        this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        toast = new Tosty(VideoRecorder.this);

        recordBtn = (Button) findViewById(R.id.recordBtn);

        recordBtn.setOnClickListener(this);

        surface = (SurfaceView) findViewById(R.id.surfaceView);

        surfaceHolder = surface.getHolder();

        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        timeView = (TextView) findViewById(R.id.timeView);

        timeView.setTextColor(Color.WHITE);

        initVideoRecording();

        initView();

        setListener();

    }

    catch (Exception e) {

        // TODO: handle exception

        e.printStackTrace();

    }

}

public void initView() {

    cameraFront = (ImageView) findViewById(R.id.cameraSwitch1);

}

public void setListener() {

    cameraFront.setOnClickListener(this);

}


@Override
protected void onResume() {

    super.onResume();

    (new Thread(new Runnable() {

        @Override
        public void run() {

            try {

                Thread.sleep(100);

            } 

            catch (InterruptedException e) {

                e.printStackTrace();

            }

            try {

                initVideoRecording();

                //finish();

            } 

            catch (Exception e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    })).start();

}

@Override
public void onDestroy() {

    super.onDestroy();
    // Stop sensorManager

    sensorManager.unregisterListener(VideoRecorder.this);

    if (autoStopTimer != null) {

        autoStopTimer.cancel();

        autoStopTimer.purge();

        autoStopTimer = null;
    }

    try {

        stopVideoRecording();

    } 

    catch (Exception e) {

        // TODO Auto-generated catch block

    }

}

@Override
public void onPause() {

    super.onPause();

    if (autoStopTimer != null) {

        autoStopTimer.cancel();

        autoStopTimer.purge();

        autoStopTimer = null;

    }

    try {

        stopVideoRecording();

    } 
    catch (Exception e) {

        // TODO Auto-generated catch block

    }

}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {

    if (keyCode == KeyEvent.KEYCODE_BACK) {

        // toast.showToast("Back button is pressed");

        sensorManager.unregisterListener(VideoRecorder.this);

        finish();

        return true;
    } 

    else if (keyCode == KeyEvent.KEYCODE_HOME) {

        try {

            stopVideoRecording();

        }

        catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

    return super.onKeyDown(keyCode, event);
}

public void onBackPressed() {
    startActivity(new Intent(this, VideoPlay.class)
    .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK));
    //overridePendingTransition(R.anim.left_right, R.anim.right_left);
    finish();
    return;
}


@Override
public void onClick(View v) {

    // TODO Auto-generated method stub

    switch (v.getId()) {

    case R.id.cameraSwitch1:



        Intent intent = new Intent(VideoRecorder.this, Cemara.class);

        //intent.putExtra("android.intent.extras.CAMERA_FACING", 1);

        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);

        //intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);

        finish();

        startActivity(intent);

        break;

    }

    if (v == recordBtn) {

        try {

            if (isRecording) {

            if (autoStopTimer != null) {

                autoStopTimer.cancel();

                autoStopTimer.purge();

                autoStopTimer = null;

            }

            try {

                stopVideoRecording();

            }

            catch (Exception e) {

                // TODO Auto-generated catch block

            }

            setResult(RESULT_OK);

            finish();

            } 

            else {

                startVideoRecording();

                autoStopTimer = new Timer();        

                autoStopTimer.schedule(new TimerTask() {

                public void run() {

                    timeCount++;

                    runOnUiThread(new Runnable() {

                        public void run() {

                            timeView.setText(String.format("00:%02d", timeCount));

                            if (timeCount == 31) {

                                try {

                                    stopVideoRecording();

                                } 

                                catch (Exception e) {
                                    // TODO Auto-generated catch block

                                }

                                setResult(RESULT_OK);

                                finish();

                            }

                        }

                    });

                    if (timeCount == 31) {

                        autoStopTimer.cancel();

                        autoStopTimer = null;

                    }

                }

                }, 1000, 1000);

            }

        }

        catch (Exception e) {
        // TODO: handle exception
        e.printStackTrace();

        }

    }

}

private void initVideoRecording() {

    try {

        if (videoRecorder != null) {

            videoRecorder.stop();

            videoRecorder.release();

            videoRecorder = null;

        }

        if (mCamera != null) {

            mCamera.reconnect();

            mCamera.stopPreview();

            mCamera.release();

            mCamera = null;

        }

        sdkVersion = Build.VERSION.SDK_INT;

        android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();

        android.hardware.Camera.getCameraInfo(0, info);

        mCamera = Camera.open();

        //parameters.setFocusMode(Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);

        //parameters.set("focus-mode", "continuous-video");

        //mCamera.setParameters(parameters);

        // Camera setup is based on the API Camera Preview demo
        mCamera.setPreviewDisplay(surfaceHolder);

        parameters = mCamera.getParameters();

        if (sdkVersion <= 8) {

            supportedSizes = parameters.getSupportedVideoSizes();

        }

        // parameters.setRotation(90);

        mCamera.setParameters(parameters);

        // check the intial orientation depending on rotation
        int rotation = getWindowManager().getDefaultDisplay().getRotation();

        int nCurrentOrientation = _getScreenOrientation();

        if (nCurrentOrientation == Configuration.ORIENTATION_PORTRAIT && rotation == Surface.ROTATION_0) {

            System.out.println("We are in portrait mode");
            // parameters.setRotation(0);

            mCamera.setDisplayOrientation(90);

        } 

        else if (nCurrentOrientation == Configuration.ORIENTATION_LANDSCAPE && rotation == Surface.ROTATION_90) {

            System.out.println("We are in landscape mode");

            // parameters.setRotation(0);

            mCamera.setDisplayOrientation(0);

        } 

        else if (nCurrentOrientation == Configuration.ORIENTATION_LANDSCAPE && rotation == Surface.ROTATION_270) {

            System.out.println("Reverse Landscape Mode");

            mCamera.setDisplayOrientation(180);

        } 

        else if (nCurrentOrientation == Configuration.ORIENTATION_PORTRAIT && rotation == Surface.ROTATION_180) {

            System.out.println("Reverse potrait mode");

            mCamera.setDisplayOrientation(90);

        }

        else

            mCamera.setDisplayOrientation(90);

        mCamera.startPreview();

        mCamera.unlock();

    } 

    catch (Exception e) {

        e.printStackTrace();

    }

}

private void stopVideoRecording() throws Exception {

    try {

    if (videoRecorder != null) {

        videoRecorder.stop();

        videoRecorder.release();

        videoRecorder = null;

    }

    if (mCamera != null) {

        mCamera.reconnect();

        mCamera.stopPreview();

        mCamera.release();

        mCamera = null;

    }

}

    catch (Exception e) {

        // TODO: handle exception

        e.printStackTrace();

    }

}

private void startVideoRecording() {

    try {

    if (videoRecorder == null) {

        videoRecorder = new MediaRecorder();

    }

    videoRecorder.setCamera(mCamera);

    videoRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);

    videoRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);

    videoRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);

    videoRecorder.setAudioEncodingBitRate(128000);

    videoRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);

    videoRecorder.setAudioChannels(1);

    videoRecorder.setAudioSamplingRate(48000);

    if (width == 1280) {

        videoRecorder.setVideoEncodingBitRate(22100000);

    } 

    else if (width == 720) {

        videoRecorder.setVideoEncodingBitRate(3508000);

    } 

    else {

        videoRecorder.setVideoEncodingBitRate(777000);

    }

    videoRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);

    videoRecorder.setVideoFrameRate(30);

    videoRecorder.setVideoSize(width, height);

    videoRecorder.setPreviewDisplay(surfaceHolder.getSurface());

    videoRecorder.setOrientationHint(90);

    if (mDetected_Orientention == PORTRAIT) {

        videoRecorder.setOrientationHint(90);

    } 

    else if (mDetected_Orientention == PORTRAIT_REV) {

        videoRecorder.setOrientationHint(270);

    } 

    else if (mDetected_Orientention == LANDSCAPE_RIGHT) {

        videoRecorder.setOrientationHint(180);

    }

    try {

        videoRecorder.setOutputFile(videoPath);

        videoRecorder.prepare();

        videoRecorder.start();

        isRecording = true;

        recordBtn.setText("STOP");

    } 

    catch (Exception e) {

        Log.e("Video", "Failed to prepare and start video recording", e);

        videoRecorder.release();

        videoRecorder = null;

    }

    }

    catch (Exception e) {

        // TODO: handle exception

        e.printStackTrace();

    }

}

@Override
public void onConfigurationChanged(Configuration newConfig) {

    super.onConfigurationChanged(newConfig);

    try {

    int rotation = getWindowManager().getDefaultDisplay().getRotation();

    int nCurrentOrientation = _getScreenOrientation();

    if (nCurrentOrientation == Configuration.ORIENTATION_PORTRAIT && rotation == Surface.ROTATION_0) {

        System.out.println("We are in portriat mode");

        // parameters.setRotation(0);

        mCamera.setDisplayOrientation(90);

        Log.e("Rotation", "90");

    } 

    else if (nCurrentOrientation == Configuration.ORIENTATION_LANDSCAPE && rotation == Surface.ROTATION_90) {

        System.out.println("We are in landscape mode");

        // parameters.setRotation(0);

        Log.e("Rotation", "0");

        mCamera.setDisplayOrientation(0);

    } 

    else if (nCurrentOrientation == Configuration.ORIENTATION_LANDSCAPE && rotation == Surface.ROTATION_270) {

        System.out.println("Reverse Landscape Mode");

        Log.e("Rotation", "180");

        mCamera.setDisplayOrientation(180);

    } 

    else if (nCurrentOrientation == Configuration.ORIENTATION_PORTRAIT && rotation == Surface.ROTATION_180) {

        System.out.println("Reverse potrait mode");

        Log.e("Rotation", "90");

        mCamera.setDisplayOrientation(90);

    }

    }

    catch (Exception e) {

        // TODO: handle exception

        e.printStackTrace();

    }

    // _doSomeThingWhenChangeOrientation(nCurrentOrientation);

}

private int _getScreenOrientation() {

    int returnOrientation = 0;

    try {

        returnOrientation = getResources().getConfiguration().orientation;

    } 

    catch (Exception e) {

        System.out.println(e.getMessage());

    }

    return returnOrientation;

}

int orientation = -1;

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {

    // TODO Auto-generated method stub

}

@Override
public void onSensorChanged(SensorEvent sensorEvent) {

    float x = sensorEvent.values[0];

    float y = sensorEvent.values[1];

    if (x >= -5 && x < 5) {

        if (y > 0) {

            mDetected_Orientention = PORTRAIT;

            //Log.e("X", "PORTRAIT");

        }

        else {

            mDetected_Orientention = PORTRAIT_REV;

            //Log.e("X", "PORTRAIT_REV");

        }

    } 

    else {

        if (x >= -10 && x < -5) {

            //Log.e("X", "LAND_RIGHT");

            mDetected_Orientention = LANDSCAPE_RIGHT;

        } 

        else {

            //Log.e("X", "LEND_LEFT");

            mDetected_Orientention = LANDSCAPE_LEFT;

        }

    }

}

}

Answer 1

这个答案 99% 抄袭自 Commonsware tutorial/code sample。我添加了一个在前后摄像头之间切换的按钮。

PreviewDemo.java

package com.commonsware.android.camera;

import java.io.IOException;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Toast;

public class PreviewDemo extends Activity {

    private static final String TAG = PreviewDemo.class.getSimpleName();
    private SurfaceView preview = null;
    private SurfaceHolder previewHolder = null;
    private Camera camera = null;
    private boolean inPreview = false;
    private boolean cameraConfigured = false;
    int cameraID = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        preview = (SurfaceView) findViewById(R.id.preview);
        previewHolder = preview.getHolder();
        previewHolder.addCallback(surfaceCallback);
        previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    @SuppressLint("NewApi")
    @Override
    public void onResume() {
        super.onResume();

        // camera = Camera.open();
        camera = Camera.open(cameraID);
        startPreview();
    }

    @Override
    public void onPause() {
        if (inPreview) {
            camera.stopPreview();
        }

        camera.release();
        camera = null;
        inPreview = false;

        super.onPause();
    }

    private Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters) {
        Camera.Size result = null;

        for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
            if (size.width <= width && size.height <= height) {
                if (result == null) {
                    result = size;
                } else {
                    int resultArea = result.width * result.height;
                    int newArea = size.width * size.height;

                    if (newArea > resultArea) {
                        result = size;
                    }
                }
            }
        }

        return (result);
    }

    private void initPreview(int width, int height) {
        if (camera != null && previewHolder.getSurface() != null) {
            try {
                camera.setPreviewDisplay(previewHolder);
            } catch (Throwable t) {
                Log.e("PreviewDemo-surfaceCallback", "Exception in setPreviewDisplay()", t);
                Toast.makeText(PreviewDemo.this, t.getMessage(), Toast.LENGTH_LONG).show();
            }

            if (!cameraConfigured) {
                Camera.Parameters parameters = camera.getParameters();
                Camera.Size size = getBestPreviewSize(width, height, parameters);

                if (size != null) {
                    parameters.setPreviewSize(size.width, size.height);
                    camera.setParameters(parameters);
                    cameraConfigured = true;
                }
            }
        }
    }

    private void startPreview() {
        Log.d(TAG, "start preview called");
        if (cameraConfigured && camera != null) {
            Log.d(TAG, "stuff works");
            camera.startPreview();
            inPreview = true;
        }
    }

    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) {
            initPreview(width, height);
            startPreview();
        }

        public void surfaceDestroyed(SurfaceHolder holder) {
            // no-op
        }
    };

    @SuppressLint("NewApi")
    public void switchCamera(View view) {
        Log.d(TAG, "switch called");
        if (inPreview) {
            camera.stopPreview();
        }
        camera.release();

        cameraID = (cameraID + 1) % 2;
        camera = Camera.open(cameraID);
        try {
            camera.setPreviewDisplay(previewHolder);
        } catch (IOException e) {
            e.printStackTrace();
        }
        camera.startPreview();
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <android.view.SurfaceView
        android:id="@+id/preview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
    </android.view.SurfaceView>

    <Button
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="switch"
        android:layout_alignParentBottom="true"
        android:onClick="switchCamera" />

</RelativeLayout>