学习Android中拍照与录像

布局文件如下：

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.zking.g150831_android27_camera_mediarecoder.MainActivity">    <SurfaceView        android:layout_width="match_parent"        android:layout_height="match_parent"        android:id="@+id/sv_main_surface"        />    <Button        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:onClick="takePhoto"        android:text="拍照"        /></RelativeLayout>
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.zking.g150831_android27_camera_mediarecoder.MediaRecorderActivity">    <SurfaceView        android:layout_width="match_parent"        android:layout_height="match_parent"        android:id="@+id/sv_media_recorder_surface"        />    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content">                <Button            android:layout_width="0dp"            android:layout_height="wrap_content"            android:text="开始"            android:onClick="start"            android:layout_weight="1"            />        <Button            android:layout_width="0dp"            android:layout_height="wrap_content"            android:text="停止"            android:onClick="stop"            android:layout_weight="1"            />    </LinearLayout></RelativeLayout>
java 代码如下：
package com.zking.g150831_android27_camera_mediarecoder;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.PixelFormat;import android.hardware.Camera;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class MainActivity extends AppCompatActivity {    PRivate SurfaceView sv_main_surface;    private Camera camera;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        sv_main_surface = (SurfaceView) findViewById(R.id.sv_main_surface);        sv_main_surface.getHolder().addCallback(new SurfaceHolder.Callback() {            @Override            public void surfaceCreated(SurfaceHolder surfaceHolder) {                //打开照相机                camera = Camera.open();                //设置参数                Camera.Parameters parameters=camera.getParameters();                parameters.setPictureFormat(PixelFormat.JPEG);                parameters.set("jpeg-quality",85);                camera.setParameters(parameters);                //将画面展示到SurfaceView                try {                    camera.setPreviewDisplay(sv_main_surface.getHolder());                    //开启预览                    camera.startPreview();                } catch (IOException e) {                    e.printStackTrace();                }            }            @Override            public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {            }            @Override            public void surfaceDestroyed(SurfaceHolder surfaceHolder) {                //关闭照相机                if(camera!=null){                    camera.release();                    camera.stopPreview();                    camera=null;                }            }        });    }    public void takePhoto(View view){        //DCIM/Camera/        camera.takePicture(null, null, new Camera.PictureCallback() {            @Override            public void onPictureTaken(byte[] bytes, Camera camera) {                //实例化文件输出流                //写                //压缩（图片）                //将字节数组转成Bitmap                Bitmap bitmap=BitmapFactory.decodeByteArray(bytes,0,bytes.length);                try {                    FileOutputStream fos=new FileOutputStream("/mnt/sdcard/dcim/camera/G150831_"+System.currentTimeMillis()+".png");                    bitmap.compress(Bitmap.CompressFormat.PNG,85,fos);                    //重新继续拍照                    camera.stopPreview();                    camera.startPreview();                } catch (FileNotFoundException e) {                    e.printStackTrace();                }            }        });    }}
package com.zking.g150831_android27_camera_mediarecoder;import android.media.MediaRecorder;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.SurfaceView;import android.view.View;import java.io.IOException;public class MediaRecorderActivity extends AppCompatActivity {    private SurfaceView sv_media_recorder_surface;    private MediaRecorder mediaRecorder;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_media_recorder);        sv_media_recorder_surface = (SurfaceView) findViewById(R.id.sv_media_recorder_surface);        //实例化媒体录制器        mediaRecorder = new MediaRecorder();    }    public void start(View view){        mediaRecorder.reset();        //设置参数        //设置音频，视频来源        mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);        //设置输出格式        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);        //设置编码格式(视频，音频)        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263);        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);        //设置保存路径        mediaRecorder.setOutputFile("/mnt/sdcard/G150831_"+System.currentTimeMillis()+".mp4");        //画面        mediaRecorder.setPreviewDisplay(sv_media_recorder_surface.getHolder().getSurface());        //准备        try {            mediaRecorder.prepare();            mediaRecorder.start();        } catch (IOException e) {            e.printStackTrace();        }    }    public void stop(View view){        mediaRecorder.stop();    }}
最后在清单文件中配置：
<activity android:name=".MediaRecorderActivity"            android:screenOrientation="landscape"            >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>