看代码学Android ：如何实现Timer控制照相机？

package com.yarin.android.Examples_07_06;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;

public class Activity01 extends Activity
{

    /* (non-Javadoc)
     * @see android.app.Activity#onDestroy()
     */
    @Override
    protected void onDestroy() {
        if( timer != null){
            timer.cancel();
        }
        // TODO Auto-generated method stub
        super.onDestroy();
    }

    /* (non-Javadoc)
     * @see android.app.Activity#onResume()
     */
    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
    }

    Timer timer = new Timer();

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.main);

    }

    public void Test(View view)
    {
        timer.schedule(new TimerTask()
        {
            public void run() {
                Log.v("CA", "TimerTask");
                Intent intent = new Intent();
                intent.setClass(Activity01.this, CameraActivity.class);
                Activity01.this.startActivity(intent);
            }
        }, 5000, 2000);
    }

    public void Stop(View view)
    {
        this.timer.cancel();
        this.finish();
    }
}

package com.yarin.android.Examples_07_06;

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

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
//import android.view.KeyEvent;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;

public class CameraActivity extends Activity {

    private Preview    mPreview = null;

    /* (non-Javadoc)
     * @see android.app.Activity#onPause()
     */
    @Override
    protected void onPause() {
        Log.v("CA", "onPause");
        if( mPreview != null ){
            mPreview = null;
        }

        super.onPause();
    }

    /* (non-Javadoc)
     * @see android.app.Activity#onResume()
     */
    @Override
    protected void onResume() {
        // Create our Preview view and set it as the content of our activity.
        Log.v("CA", "onResume");

        super.onResume();
    }


    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);

        mPreview = new Preview(this);
        setContentView(mPreview);
    }



/* Preview-显示Preview */
class Preview extends SurfaceView implements SurfaceHolder.Callback
{
    SurfaceHolder mHolder = null;
    Camera mCamera = null;
    Bitmap CameraBitmap = null;

    Preview(Context context)
    {
        super(context);
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void startCamera() {
        Log.v("CA", "startCamera");

        if (mCamera == null) {
            try {
                mCamera = Camera.open();
                Log.v("CA", "Camera.open");
            } catch (Exception e) {
            }

        } else {
            try {
                mCamera.reconnect();
            } catch (IOException e) {
                mCamera.release();
                mCamera = null;
            }
        }

    }

    public void stopCamera() {
        Log.v("CA", "stopCamera");

        if (mCamera != null) {
            try {
                mCamera.stopPreview();
            } catch (Exception e) {
                // Ignore
            }

            try {
                mCamera.release();
                Log.v("CA", "mCamera.release");
            } catch (Exception e) {
                // Ignore
            }

            mCamera = null;
        }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder)
    {
        Log.v("CA", "surfaceCreated");

        startCamera();

        if( mCamera == null ) return;

        Log.v("CA", "Camera create!");

        try {
            mCamera.setPreviewDisplay(holder);
        } catch (IOException e) {
            mCamera.release();
            mCamera = null;
            e.printStackTrace();
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder)
    {
        Log.v("CA", "surfaceDestroyed");
        stopCamera();
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h)
    {
        Log.v("CA", "surfaceChanged");
        if( holder.isCreating() && mCamera != null ){

            if( mCamera != null ){
                /* 构建Camera.Parameters对相机的参数进行设置 */
                //Camera.Parameters parameters = mCamera.getParameters();
                /* 设置拍照的图片格式 */
                //parameters.setPictureFormat(PixelFormat.JPEG);
                /* 设置Preview的尺寸 */
                //parameters.setPreviewSize(320, 480);
                /* 设置图像分辨率 */
                //parameters.setPictureSize(320, 480);
                /* 设置相机采用parameters */
                //mCamera.setParameters(parameters);
                /* 开始预览 */
                mCamera.startPreview();

                CameraActivity.this.finish();
            }
        }
    }
    /* 拍照片 */
    public void takePicture()
    {
      if (mCamera != null)
      {
          mCamera.takePicture(null, null, jpegCallback);
      }
    }
    /* 拍照后输出图片 */
    private PictureCallback jpegCallback = new PictureCallback()
    {
      public void onPictureTaken(byte[] _data, Camera _camera)
      {
        // TODO Handle JPEG image data
        CameraBitmap = BitmapFactory.decodeByteArray(_data, 0, _data.length);
        File myCaptureFile = new File("/sdcard/camera1.jpg");
        try
        {
          BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
          CameraBitmap.compress(Bitmap.CompressFormat.JPEG, 80, bos);
          bos.flush();
          bos.close();
          /* 将拍到的图片绘制出来 */
          Canvas canvas= mHolder.lockCanvas();
          canvas.drawBitmap(CameraBitmap, 0, 0, null);
          mHolder.unlockCanvasAndPost(canvas);

        }
        catch (Exception e)
        {
            e.getMessage();
        }
      }
    };
}

}