android中的多媒体应用camera

MainActivity.java

1. 代码  
2.  
3. package com.amaker.ch11.app;  
4.  
5. import java.io.File;  
6. import java.io.FileOutputStream;  
7. import java.io.IOException;  
8.  
9. import android.app.Activity;  
10. import android.graphics.PixelFormat;  
11. import android.hardware.Camera;  
12. import android.os.AsyncTask;  
13. import android.os.Bundle;  
14. import android.os.Environment;  
15. import android.view.KeyEvent;  
16. import android.view.SurfaceHolder;  
17. import android.view.SurfaceView;  
18.  
19. public class MainActivity extends Activity {  
20.     // 声明拍照界面组件SurfaceView  
21.     private SurfaceView surfaceView;  
22.     // 声明界面控制组件SurfaceHolder  
23.     private SurfaceHolder surfaceHolder;  
24.     // 声明照相机  
25.     private Camera camera;  
26.       
27.     @Override  
28.     public void onCreate(Bundle savedInstanceState) {  
29.         super.onCreate(savedInstanceState);  
30.         setContentView(R.layout.main);  
31.         // 实例化拍照界面组件  
32.         surfaceView = (SurfaceView)findViewById(R.id.preview);  
33.         // 从SurfaceView中获得SurfaceHolder  
34.         surfaceHolder = surfaceView.getHolder();  
35.         // 为SurfaceHolder 添加回调  
36.         surfaceHolder.addCallback(surfaceCallback);  
37.         surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);  
38.     }  
39.       
40.     // 响应按键事件  
41.     @Override  
42.     public boolean onKeyDown(int keyCode, KeyEvent event) {  
43.         if(keyCode==KeyEvent.KEYCODE_CAMERA||keyCode==KeyEvent.KEYCODE_SEARCH){  
44.             takePic();  
45.             return true;  
46.         }  
47.         return super.onKeyDown(keyCode, event);  
48.     }  
49.     // 拍照方法  
50.     private void takePic(){  
51.         // 停止预览  
52.         camera.stopPreview();  
53.         // 拍照  
54.         camera.takePicture(null,null, pictureCallback);  
55.     }  
56.     // 照片回调  
57.     Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {  
58.         @Override  
59.         public void onPictureTaken(byte[] data, Camera camera) {  
60.             new SavePictureTask().execute(data);  
61.             camera.startPreview();  
62.         }  
63.     };  
64.       
65.     // 保存照片任务类  
66.     class SavePictureTask extends AsyncTask<byte[],String,String>{  
67.         @Override  
68.         protected String doInBackground(byte[]... params) {  
69.             // 创建文件  
70.             File picture = new File(Environment.getExternalStorageDirectory(),"picture.jpg");  
71.             // 如果文件存在删除掉  
72.             if(picture.exists())picture.delete();  
73.             try {  
74.                 // 获得文件输出流  
75.                 FileOutputStream  fos = new FileOutputStream(picture.getPath());  
76.                 // 写到该文件  
77.                 fos.write(params[0]);  
78.                 // 关闭文件流  
79.                 fos.close();  
80.             } catch (Exception e) {  
81.                 e.printStackTrace();  
82.             }  
83.             return null;  
84.         }  
85.     }  
86.     // SurfaceHodler 回调，处理打开相机，关闭相机以及照片尺寸的改变  
87.     SurfaceHolder.Callback surfaceCallback = new SurfaceHolder.Callback() {  
88.         @Override  
89.         public void surfaceCreated(SurfaceHolder holder) {  
90.             // 打开相机  
91.             camera = Camera.open();  
92.             try {  
93.                 // 设置预览  
94.                 camera.setPreviewDisplay(holder);  
95.             } catch (IOException e) {  
96.                 e.printStackTrace();  
97.             }  
98.         }  
99.           
100.         @Override  
101.         public void surfaceChanged(SurfaceHolder holder, int format, int width,  
102.                 int height) {  
103.             // 获得相机参数  
104.             Camera.Parameters parameters = camera.getParameters();  
105.             // 设置照片大小  
106.             parameters.setPreviewSize(width, height);  
107.             // 设置照片格式  
108.             parameters.setPictureFormat(PixelFormat.JPEG);  
109.             // 设置相机参数  
110.             camera.setParameters(parameters);  
111.             // 开始预览  
112.             camera.startPreview();  
113.         }  
114.           
115.         @Override  
116.         public void surfaceDestroyed(SurfaceHolder holder) {  
117.             // 停止预览  
118.             camera.stopPreview();  
119.             // 释放相机资源  
120.             camera.release();  
121.             camera = null;  
122.         }  
123.     };  
124. } 

代码

package com.amaker.ch11.app;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.view.KeyEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class MainActivity extends Activity {
    // 声明拍照界面组件SurfaceView
    private SurfaceView surfaceView;
    // 声明界面控制组件SurfaceHolder
    private SurfaceHolder surfaceHolder;
    // 声明照相机
    private Camera camera;
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // 实例化拍照界面组件
        surfaceView = (SurfaceView)findViewById(R.id.preview);
        // 从SurfaceView中获得SurfaceHolder
        surfaceHolder = surfaceView.getHolder();
        // 为SurfaceHolder 添加回调
        surfaceHolder.addCallback(surfaceCallback);
        surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }
    
    // 响应按键事件
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode==KeyEvent.KEYCODE_CAMERA||keyCode==KeyEvent.KEYCODE_SEARCH){
            takePic();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
    // 拍照方法
    private void takePic(){
        // 停止预览
        camera.stopPreview();
        // 拍照
        camera.takePicture(null,null, pictureCallback);
    }
    // 照片回调
    Camera.PictureCallback pictureCallback = new Camera.PictureCallback() {
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            new SavePictureTask().execute(data);
            camera.startPreview();
        }
    };
    
    // 保存照片任务类
    class SavePictureTask extends AsyncTask<byte[],String,String>{
        @Override
        protected String doInBackground(byte[]... params) {
            // 创建文件
            File picture = new File(Environment.getExternalStorageDirectory(),"picture.jpg");
            // 如果文件存在删除掉
            if(picture.exists())picture.delete();
            try {
                // 获得文件输出流
                FileOutputStream  fos = new FileOutputStream(picture.getPath());
                // 写到该文件
                fos.write(params[0]);
                // 关闭文件流
                fos.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    }
    // SurfaceHodler 回调，处理打开相机，关闭相机以及照片尺寸的改变
    SurfaceHolder.Callback surfaceCallback = new SurfaceHolder.Callback() {
        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            // 打开相机
            camera = Camera.open();
            try {
                // 设置预览
                camera.setPreviewDisplay(holder);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        
        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width,
                int height) {
            // 获得相机参数
            Camera.Parameters parameters = camera.getParameters();
            // 设置照片大小
            parameters.setPreviewSize(width, height);
            // 设置照片格式
            parameters.setPictureFormat(PixelFormat.JPEG);
            // 设置相机参数
            camera.setParameters(parameters);
            // 开始预览
            camera.startPreview();
        }
        
        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {
            // 停止预览
            camera.stopPreview();
            // 释放相机资源
            camera.release();
            camera = null;
        }
    };
}

本文转自linzheng 51CTO博客，原文链接:http://blog.51cto.com/linzheng/1079348