Android手机拍照

参考的这个视频教程：http://v.youku.com/v_show/id_XNjI5MzkzMjQ4.html和官方API档file:///D:/Android/androidstudio/sdk/docs/guide/topics/media/camera.html

java程序

package com.example.x_yp.system_camera;


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

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PictureCallback;

public class MainActivity extends Activity {
    protected static final String TAG = "main";
    private Camera mCamera;
    private CameraPreview mPreview;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mCamera = getCameraInstance();

        // 创建预览类，并与Camera关联，最后添加到界面布局中
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);


        Button captureButton = (Button) findViewById(R.id.button_capture);
        captureButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // 在捕获图片前进行自动对焦
                mCamera.autoFocus(new AutoFocusCallback() {
                    
                    @Override
                    public void onAutoFocus(boolean success, Camera camera) {
                        // 从Camera捕获图片
                        mCamera.takePicture(null, null, mPicture);
                    }
                });                
            }
        });
    }

    /** 检测设备是否存在Camera硬件 */
    private boolean checkCameraHardware(Context context) {
        if (context.getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA)) {
            // 存在
            return true;
        } else {
            // 不存在
            return false;
        }
    }

    /** 打开一个Camera */
    public static Camera getCameraInstance() {
        Camera c = null;
        try {
            c = Camera.open(); 
        } catch (Exception e) {
            Log.d(TAG, "打开Camera失败失败");
        }
        return c; 
    }

    private PictureCallback mPicture = new PictureCallback() {

        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            // 获取Jpeg图片，并保存在sd卡上
            File pictureFile = new File("/sdcard/" + System.currentTimeMillis() + ".jpg");
            try {
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.close();
            } catch (Exception e) {
                Log.d(TAG, "保存图片失败");
            }
        }
    };

    @Override
    protected void onDestroy() {
        // 回收Camera资源
        if(mCamera!=null){
            mCamera.stopPreview();
            mCamera.release();
            mCamera=null;
        }
        super.onDestroy();
    }
    
}

package com.example.x_yp.system_camera;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**
 * 定义一个预览类
 */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private static final String TAG = "main";
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // 通过SurfaceView获得SurfaceHolder
        mHolder = getHolder();
        // 为SurfaceHolder指定回调
        mHolder.addCallback(this);
        // 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界面 在Android3.0之后弃用
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // 当Surface被创建之后，开始Camera的预览
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d(TAG, "预览失败");
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // Surface发生改变的时候将被调用，第一次显示到界面的时候也会被调用
        if (mHolder.getSurface() == null){
          // 如果Surface为空，不继续操作
          return;
        }

        // 停止Camera的预览
        try {
            mCamera.stopPreview();
        } catch (Exception e){
            Log.d(TAG, "当Surface改变后，停止预览出错");
        }

        // 在预览前可以指定Camera的各项参数

        // 重新开始预览
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            Log.d(TAG, "预览Camera出错");
        }
    }
}

 布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <FrameLayout
        android:id="@+id/camera_preview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        />

    <Button
        android:id="@+id/button_capture"
        android:text="Capture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        />
</LinearLayout>

权限设置

 <uses-permission android:name="android.permission.CAMERA" />
    <uses-feature android:name="android.hardware.camera" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />