14_摄像头相关的

#1 摄像demo：

（1.1）布局文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:orientation="vertical"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.y81022671.a11_takevideo_first.MainActivity">    <SurfaceView        android:id="@+id/surView"        android:layout_width="match_parent"        android:layout_height="match_parent" />    <LinearLayout        android:orientation="horizontal"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:gravity="center_horizontal"        android:layout_alignParentBottom="true"        android:layout_centerHorizontal="true">        <Button            android:id="@+id/record"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="摄像"/>        <Button            android:id="@+id/stop"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="停止"/>    </LinearLayout></RelativeLayout>

（1.2）Activity类：

package com.example.y81022671.a11_takevideo_first;import android.media.MediaRecorder;import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.Surface;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import android.widget.Button;import java.io.File;import java.text.SimpleDateFormat;import java.util.Date;public class MainActivity extends AppCompatActivity implements View.OnClickListener {    Button record, stop;    File videoFile;    MediaRecorder mediaRecorder;    SurfaceView surfaceView;    private boolean isRecording = false;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        record = (Button) findViewById(R.id.record);        stop = (Button) findViewById(R.id.stop);        stop.setEnabled(false);        record.setOnClickListener(this);        stop.setOnClickListener(this);        surfaceView = (SurfaceView) findViewById(R.id.surView);        surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);        surfaceView.getHolder().setFixedSize(320, 280);        surfaceView.getHolder().setKeepScreenOn(true);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.record: {                try {                    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());                    String name = "/MP4_" + timeStamp + ".mp4";                    videoFile = new File(Environment.getExternalStorageDirectory().getCanonicalFile() + name);                    mediaRecorder = new MediaRecorder();                    mediaRecorder.reset();                    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);                    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);                    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);                    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);                    mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);                    //mediaRecorder.setVideoSize(320, 280);                    //mediaRecorder.setVideoFrameRate(4);                    mediaRecorder.setOutputFile(videoFile.getAbsolutePath());                    mediaRecorder.setPreviewDisplay(surfaceView.getHolder().getSurface());                    mediaRecorder.prepare();                    //这句代码执行出错                    Log.e("------", "before start");                    mediaRecorder.start();                    Log.e("------", "after start");                    record.setEnabled(false);                    stop.setEnabled(true);                    isRecording = true;                } catch (Exception ex) {                    ex.printStackTrace();                }                break;            }            case R.id.stop: {                if (isRecording) {                    mediaRecorder.stop();                    mediaRecorder.release();                    mediaRecorder = null;                    record.setEnabled(true);                    stop.setEnabled(false);                }                break;            }        }    }}

（1.3）清单文件：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.y81022671.a11_takevideo_first">    <uses-permission android:name="android.permission.CAMERA"/>    <uses-permission android:name="android.permission.RECORD_AUDIO"/>    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:roundIcon="@mipmap/ic_launcher_round"        android:supportsRtl="true"        android:theme="@style/AppTheme">        <activity android:name=".MainActivity">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

#2  拍照demo：

（2.1）布局文件:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    xmlns:tools="http://schemas.android.com/tools"    android:orientation="horizontal"    android:layout_width="match_parent"    android:layout_height="match_parent"    tools:context="com.example.y81022671.a13_takepicture_third.MainActivity">    <FrameLayout        android:id="@+id/frame"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:layout_weight="1">        <SurfaceView            android:id="@+id/surView"            android:layout_width="match_parent"            android:layout_height="match_parent" />    </FrameLayout>    <Button        android:id="@+id/photo"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_gravity="center"        android:text="拍照"/></LinearLayout>

（2.1）清单文件：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.y81022671.a13_takepicture_third">    <uses-permission android:name="android.permission.CAMERA"/>    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        android:roundIcon="@mipmap/ic_launcher_round"        android:supportsRtl="true"        android:theme="@style/AppTheme">        <activity android:name=".MainActivity">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>

（2.3）Activity中：
package com.example.y81022671.a13_takepicture_third;import android.hardware.Camera;import android.os.Environment;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import android.widget.Button;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.Date;public class MainActivity extends AppCompatActivity implements SurfaceHolder.Callback, View.OnClickListener, Camera.PreviewCallback {    private Button photo;    private SurfaceView surfaceView;    private Camera camera;    private boolean isCameraPreviewing = false;    private boolean isButtonClicked = false;    private File photoFile;    private byte[] everyFrameBytes420sp;    private static File pictureDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "201771_MyCameraApp");    private Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {        @Override        public void onPictureTaken(byte[] data, Camera camera) {            String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());            File pictureFile = new File(pictureDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpeg");            FileOutputStream fos = null;            try {                fos = new FileOutputStream(pictureFile);                //这里的data是当时那一瞬间抓到的那一帧数据！                fos.write(data);                fos.flush();                fos.close();            } catch (FileNotFoundException e) {                e.printStackTrace();            } catch (IOException e) {                e.printStackTrace();            }            android.os.Process.killProcess(android.os.Process.myPid());        }    };;    private int i = 0;    private int j = 0;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        surfaceView = (SurfaceView) findViewById(R.id.surView);        photo = (Button) findViewById(R.id.photo);        surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);        surfaceView.getHolder().setFixedSize(320, 280);        surfaceView.getHolder().setKeepScreenOn(true);        surfaceView.getHolder().addCallback(this);        photo.setOnClickListener(this);    }    //实现了SurfaceHolder.Callback类的这个方法：当SurfaceView创建的时候！    @Override    public void surfaceCreated(SurfaceHolder holder) {        camera = Camera.open();        camera.setDisplayOrientation(90);        Camera.Parameters p = camera.getParameters();        //p.set("orientation", "landscape");        //p.set("rotation", 90);        camera.setPreviewCallback(this);        isCameraPreviewing = true;        try {            camera.setPreviewDisplay(surfaceView.getHolder());        } catch (IOException e) {            e.printStackTrace();        }    }    //实现了SurfaceHolder.Callback类的这个方法：当SurfaceView的内容发生变化时！    @Override    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {        /*if (isCameraPreviewing) {            camera.stopPreview();        }*/        /*if (isCameraPreviewing) {            camera.stopPreview();        }        */        long time = System.currentTimeMillis();        Log.e("---------", "surface_changed_"+ time + "____" + j);        j++;        camera.startPreview();    }    //实现了SurfaceHolder.Callback类的这个方法：当SurfaceView销毁的时候！    @Override    public void surfaceDestroyed(SurfaceHolder holder) {        camera.stopPreview();        camera.release();        isCameraPreviewing = false;    }    //实现了View.OnClickListener类的这个方法：按钮点击事件    @Override    public void onClick(View v) {        //拍照        camera.takePicture(null, null, pictureCallback);    }    //实现了Camera.PreviewCallback类的这个方法：那么就可以获取相机预览时地每一帧数据！    @Override    public void onPreviewFrame(byte[] data, Camera camera) {        long time = System.currentTimeMillis();        Log.e("---------", ""+ time + "____" + i);        i++;        everyFrameBytes420sp = data;    }}

#3