Android学习笔记_26_多媒体之拍照

一、配置文件：

　　需要引入摄像头权限，sdcard读写权限。

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.example.takepicture"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="17" />

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <!-- screenOrientation设置activity在屏幕上显示方式：横向 -->

        <activity

            android:name="com.example.takepicture.MainActivity"

            android:label="@string/app_name"

            android:screenOrientation="landscape" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

    <!-- 摄像头权限  -->

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

    <!-- 在SDCard中创建与删除文件权限 -->

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

    <!-- 往SDCard写入数据权限 -->

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

</manifest>

　　布局文件，当activity启动时在屏幕上横向显示，手指触摸屏幕时，出现拍照和对焦两个按钮，采用相对布局。

<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=".MainActivity" >

    <SurfaceView

        android:id="@+id/surfaceView"

        android:layout_width="match_parent"

        android:layout_height="match_parent" />

    <RelativeLayout

        android:id="@+id/buttonlayout"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:visibility="gone" >

        <Button

            android:id="@+id/autofouce"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_alignParentBottom="true"

            android:layout_alignParentRight="true"

            android:layout_alignTop="@+id/takePicture"

            android:layout_marginRight="5dp"

            android:layout_toLeftOf="@+id/takePicture"

            android:onClick="takePicture"

            android:text="@string/autofouce" />

        <Button

            android:id="@+id/takePicture"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_alignParentBottom="true"

            android:layout_alignParentRight="true"

            android:layout_marginRight="59dp"

            android:onClick="takePicture"

            android:text="@string/takepicture" />

    </RelativeLayout>

</RelativeLayout>

二、代码实现：

package com.example.takepicture;

import java.io.File;

import java.io.FileOutputStream;

import android.app.Activity;

import android.graphics.Bitmap;

import android.graphics.Bitmap.CompressFormat;

import android.graphics.BitmapFactory;

import android.graphics.PixelFormat;

import android.hardware.Camera;

import android.os.Bundle;

import android.util.Log;

import android.view.Menu;

import android.view.MotionEvent;

import android.view.SurfaceHolder;

import android.view.SurfaceView;

import android.view.View;

import android.view.ViewGroup;

import android.view.Window;

import android.view.WindowManager;

public class MainActivity extends Activity {

    private View layout;

    private static final String TAG = "TakePicture";

    private SurfaceView surfaceView;

    private Camera camera;

    private boolean preview;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        //设置窗口没有标题

        requestWindowFeature(Window.FEATURE_NO_TITLE);

        //全屏显示

        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,

                WindowManager.LayoutParams.FLAG_FULLSCREEN);

        //getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);//高亮

        setContentView(R.layout.activity_main);

        layout= this.findViewById(R.id.buttonlayout);

        //确定surfaceView什么时候被时间

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

        surfaceView.getHolder().addCallback(new SufaceListener());

        /*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/

        surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        surfaceView.getHolder().setFixedSize(176, 144);    //设置分辨率

        surfaceView.getHolder().setKeepScreenOn(true);//设置高亮

    }

    //触摸事件

    public boolean onTouchEvent(MotionEvent event) {

        //手指按下屏幕

        if(event.getAction()==MotionEvent.ACTION_DOWN){

            layout.setVisibility(ViewGroup.VISIBLE);//显示布局

            return true;

        }

        return super.onTouchEvent(event);

    }

    private final class SufaceListener implements SurfaceHolder.Callback{

        @Override

        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

        }

        @Override

        public void surfaceCreated(SurfaceHolder holder) {

            try {

                Log.i(TAG, "surfaceCreated .... ");

                camera = Camera.open();//打开摄像头

                Camera.Parameters parameters = camera.getParameters();

                Log.i(TAG, parameters.flatten());//打印参数

                //WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);

                //Display display = wm.getDefaultDisplay();

                //图片大小的设置要符合手机上图片大小，否则会出现参数设置错误

                //parameters.setPreviewSize(display.getWidth(), display.getHeight());//设置预览照片的大小

                parameters.setPreviewFrameRate(3);//每秒3帧

                parameters.setPictureFormat(PixelFormat.JPEG);//设置照片的输出格式

                parameters.set("jpeg-quality", 85);//照片质量

                //parameters.setPictureSize(display.getWidth(), display.getHeight());//设置照片的大小

                camera.setParameters(parameters);

                camera.setPreviewDisplay(surfaceView.getHolder());//通过SurfaceView显示取景画面

                camera.startPreview();

                preview = true;

                Log.i(TAG, "surfaceCreated .. end .. ");

            } catch (Exception e) {

                Log.e(TAG, e.toString());

            }

        }

        @Override

        public void surfaceDestroyed(SurfaceHolder holder) {

            //是否摄像头

            if(camera!=null){

                if(preview) camera.stopPreview();

                camera.release();

                camera = null;

            }

        }

    }

    public void takePicture(View v){

        if (camera!=null) {

            switch (v.getId()) {

            case R.id.takePicture:

                Log.i(TAG, " start take picture ... ");

                //内部采用异步操作照片

                camera.takePicture(null, null, new PictureCallbackListener());

                Log.i(TAG, " end take picture ... ");

                break;

            case R.id.autofouce:

                camera.autoFocus(null);//自动对焦

                break;

            }

        }

    }

    /*

    @Override

    public boolean onKeyDown(int keyCode, KeyEvent event) {

        if(camera!=null && event.getRepeatCount()==0){

            switch (keyCode) {

            case KeyEvent.KEYCODE_SEARCH:

                camera.autoFocus(null);//自动对焦

                break;

            case KeyEvent.KEYCODE_DPAD_CENTER:

            case KeyEvent.KEYCODE_CAMERA:

                //拍照

                //camera.takePicture(null, null, new PictureCallbackListener());

                break;

            }

        }

        return true;

    }

*/

    private final class PictureCallbackListener implements Camera.PictureCallback{

        /**

         * data:所拍摄图片数据

         */

        @Override

        public void onPictureTaken(byte[] data, Camera camera) {

            try {

                Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

//                File file = new File(Environment.getExternalStorageDirectory(), "my.jpg");

                File file=new File("/storage/sdcard0/360/",System.currentTimeMillis()+".jpg");

                FileOutputStream outStream = new FileOutputStream(file);

                bitmap.compress(CompressFormat.JPEG, 100, outStream);

                outStream.close();

                //重新浏览，否则画面就不动

                   camera.stopPreview();

                camera.startPreview();

                preview = true;

            } catch (Exception e) {

                Log.e(TAG, e.toString());

            }

        }

    }

    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        getMenuInflater().inflate(R.menu.main, menu);

        return true;

    }

}

三、出现异常：

　　设置摄像头参数时，尤其是图片大小要符合手机匹配图片大小，否则会出现设置参数错误。