Android相机的实现

由于电脑的原因，搞 了几天，今天才能学习~唉！

相机，在Android中，有一个类Camera，我们只要了解其中的方法就可以很快会用，个中方法请参照官方文档！

以下为本人打的代码：

MainActivity.java:

package com.chiefcto.camera;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Window;
import android.view.WindowManager;

public class MainActivity extends Activity {
    //Properties
    private Preview mPreview;
    
    
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        
        mPreview = new Preview(MainActivity.this);
        setContentView(mPreview);
    }

    @Override
    public boolean onKeyUp(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        switch (keyCode) {
        case KeyEvent.KEYCODE_DPAD_CENTER:
            mPreview.takePicture();
            break;
        }
        return true;
    }
    
    
}

Preview.java:

package com.chiefcto.camera;

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

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.view.SurfaceHolder;
import android.view.SurfaceView;

public class Preview extends SurfaceView implements SurfaceHolder.Callback{
    //Properties
    SurfaceHolder mHolder;
    Camera mCamera;
    Bitmap cameraBitmap;
    
    public Preview(Context context) {
        super(context);
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPictureFormat(PixelFormat.JPEG);
        parameters.setPictureSize(320, 480);
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);
        }
        catch (IOException e) {
            mCamera.release();
            mCamera = null;
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCamera.stopPreview();
        mCamera = null;
    }

    public void takePicture() {
        if(mCamera != null) {
            mCamera.takePicture(null, null, jpegCallback);
        }
    }
    
    private PictureCallback jpegCallback = new PictureCallback() {
        
        @Override
        public void onPictureTaken(byte[] data, Camera camera) {
            cameraBitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
            File myCaptureFile = new File("/sdcard/camera/camera1.jpg");
            try {
                BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(myCaptureFile));
                cameraBitmap.compress(Bitmap.CompressFormat.JPEG, 80, bos);
                bos.flush();
                bos.close();
                Canvas canvas = mHolder.lockCanvas();
                canvas.drawBitmap(cameraBitmap, 0, 0, null);
                mHolder.unlockCanvasAndPost(canvas);
            }
            catch (Exception e) {
                e.getStackTrace();
            }
        }
    };

}

PS:在虚拟机中是运行不了的，因为其没有摄相头，所以得用真机。当然，也可以调用电脑的摄相头代替。