Android Camera开发：给摄像头预览界面加个ZoomBar（附完整代码下载）

源码：http://files.cnblogs.com/android100/StandardCamera2013-10-18.zip

废话不说了，就是加个seekbar，拖动的话能够调节焦距，让画面变大或缩小。下面是核心程序：

一，camera的布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/BestWish"
        tools:context=".StandardCamera" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <FrameLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <SurfaceView
                android:id="@+id/previewSV"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content" />
        </FrameLayout>

        <LinearLayout
        android:id="@+id/zoomLayout"
        android:layout_width="wrap_content"
        android:layout_height="40dp"
        android:layout_centerInParent="true"
        android:layout_centerHorizontal="true"
        android:orientation="horizontal" >

        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="-"
            android:textColor="#ffffff"
            android:textSize="30dip"/>

        <SeekBar
            android:id="@+id/seekbar_zoom"
            android:layout_width="300dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
           android:progressDrawable="@drawable/seekbar_style"
            android:thumb="@drawable/ic_launcher"
            android:thumbOffset="0dp" />

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
             android:text="+"
            android:textColor="#ffffff"
            android:textSize="30dip" />
    </LinearLayout>
    </RelativeLayout>



    <ImageButton
        android:id="@+id/photoImgBtn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:background="@drawable/photo_img_btn" />

</LinearLayout>

其中里面嵌套的LinearLayout就是那个ZoomBar，最外面我用了相对布局，发现相对布局用起来还是很好用的。为了方便以后扩展，Camera的SurfaceView用的帧布局。注意SeekBar的几个参数，其中的progressDrawable是指那个横条的形状，可以直接用个图片，也可以写个xml文件。这里用的是xml，当然用图片很简单。seekbar_style.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:id="@android:id/background">
         <shape>
             <corners android:radius="5dip" />
             <gradient
                     android:startColor="#ff9d9e9d"
                     android:centerColor="#ff5a5d5a"
                     android:centerY="0.75"
                     android:endColor="#ff747674"
                     android:angle="270"
             />
         </shape>
     </item>
</layer-list>

下面的android:thumb是滑动的那个手柄，本来我是写了一个xml文件，名字为thumb.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- 按下状态 -->
    <item android:state_focused="true" android:state_pressed="true"><shape android:shape="oval">
            <gradient android:angle="0" android:centerColor="#FF00FF00" android:endColor="#000000" android:gradientRadius="8" android:startColor="#FFFF0000" android:type="radial" />

            <size android:height="20dip" android:width="20dip"></size>
        </shape></item>


</selector>

无奈啥也显示不出来，索性直接找了个粗糙的图片，见谅哈！

二，整个程序的主代码：

package yan.guoqi.camera;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;

import yan.guoqi.rectphoto.R;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Matrix;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.PictureCallback;
import android.hardware.Camera.PreviewCallback;
import android.hardware.Camera.ShutterCallback;
import android.os.Bundle;
import android.util.Log;
import android.view.Display;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.view.ViewGroup.LayoutParams;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;

public class StandardCamera extends Activity implements SurfaceHolder.Callback, PreviewCallback{
    private static final String tag="StandardCamera";
    private boolean isPreview = false;
    private SurfaceView mPreviewSV = null; //棰勮�SurfaceView
    private SurfaceHolder mySurfaceHolder = null;
    private ImageButton mPhotoImgBtn = null;
    private Camera myCamera = null;
    private Bitmap mBitmap = null;
    private AutoFocusCallback myAutoFocusCallback = null;
    boolean flag = true;

    private SeekBar mZoomBar = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        int flag = WindowManager.LayoutParams.FLAG_FULLSCREEN;
        Window myWindow = this.getWindow();
        myWindow.setFlags(flag, flag);

        setContentView(R.layout.activity_rect_photo);

        initView();
        mySurfaceHolder = mPreviewSV.getHolder();
        mySurfaceHolder.setFormat(PixelFormat.TRANSLUCENT);
        mySurfaceHolder.addCallback(this);
        mySurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);


        myAutoFocusCallback = new AutoFocusCallback() {

            public void onAutoFocus(boolean success, Camera camera) {
                // TODO Auto-generated method stub
                if(success)
                {
                    Log.i(tag, "myAutoFocusCallback: success...");


                }
                else
                {
                    Log.i(tag, "myAutoFocusCallback: 澶辫触浜�?.");

                }


            }
        };

        //添加ZoomBar
        mZoomBar = (SeekBar)findViewById(R.id.seekbar_zoom);
        mZoomBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

            public void onStopTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            public void onStartTrackingTouch(SeekBar seekBar) {
                // TODO Auto-generated method stub

            }

            public void onProgressChanged(SeekBar seekBar, int progress,
                    boolean fromUser) {
                // TODO Auto-generated method stub
                Parameters p = myCamera.getParameters();
                p.setZoom(progress);
                myCamera.setParameters(p);
            }
        });



    }

    public void initView(){
        mPreviewSV = (SurfaceView)findViewById(R.id.previewSV);
        WindowManager wm = (WindowManager)getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();
        LayoutParams lpSV = mPreviewSV.getLayoutParams();
        lpSV.width = display.getWidth();
        lpSV.height = (int) ((float)display.getHeight()*0.75);
        mPreviewSV.setLayoutParams(lpSV);


            mPhotoImgBtn = (ImageButton)findViewById(R.id.photoImgBtn);
        LayoutParams lp = mPhotoImgBtn.getLayoutParams();
        lp.width = 240;
        lp.height = 240;
        mPhotoImgBtn.setLayoutParams(lp);
        mPhotoImgBtn.setOnClickListener(new PhotoOnClickListener());
        mPhotoImgBtn.setOnTouchListener(new MyOnTouchListener());
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int width,int height)
    {
        // TODO Auto-generated method stub
        Log.i(tag, "SurfaceHolder.Callback:surfaceChanged!");
        initCamera();

    }


    public void surfaceCreated(SurfaceHolder holder)
    {
        // TODO Auto-generated method stub
        myCamera = Camera.open();
        try {
            myCamera.setPreviewDisplay(mySurfaceHolder);
            Log.i(tag, "SurfaceHolder.Callback: surfaceCreated!");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            if(null != myCamera){
                myCamera.release();
                myCamera = null;
            }
            e.printStackTrace();
        }



    }


    public void surfaceDestroyed(SurfaceHolder holder)

    {
        // TODO Auto-generated method stub
        Log.i(tag, "SurfaceHolder.Callback锛歋urface Destroyed");
        if(null != myCamera)
        {
            myCamera.setPreviewCallback(null);

            myCamera.stopPreview();
            isPreview = false;
            myCamera.release();
            myCamera = null;
        }

    }

    public void initCamera(){
        if(isPreview){
            myCamera.stopPreview();
        }
        if(null != myCamera){
            Camera.Parameters myParam = myCamera.getParameters();


            myParam.setPictureFormat(PixelFormat.JPEG);//璁剧疆鎷嶇収鍚庡瓨鍌ㄧ殑鍥剧墖鏍煎紡


            //List<Size> pictureSizes = myParam.getSupportedPictureSizes();
                        //List<Size> previewSizes = myParam.getSupportedPreviewSizes();
            //          for(int i=0; i<pictureSizes.size(); i++){
            //              Size size = pictureSizes.get(i);
            //              Log.i(tag, "initCamera:pictureSizes: width = "+size.width+"height = "+size.height);
            //          }
            //          for(int i=0; i<previewSizes.size(); i++){
            //              Size size = previewSizes.get(i);
            //              Log.i(tag, "initCamera:鎽勫儚澶存敮鎸佺殑previewSizes: width = "+size.width+"height = "+size.height);
            //
            //          }



            myParam.setPictureSize(1280, 960);  //
            myParam.setPreviewSize(960, 720);   //
            //myParam.set("rotation", 90);
            myCamera.setDisplayOrientation(90);
            List<String> focuseMode = (myParam.getSupportedFocusModes());
            for(int i=0; i<focuseMode.size(); i++){
                Log.i(tag, focuseMode.get(i));
                if(focuseMode.get(i).contains("continuous")){
                    myParam.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
                }
                else{
                    myParam.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);

                }
            }
            //设置mZoomBar的最大值
            mZoomBar.setMax(myParam.getMaxZoom());
            myCamera.setParameters(myParam);
            myCamera.startPreview();
            myCamera.autoFocus(myAutoFocusCallback);
            isPreview = true;
        }
    }

    ShutterCallback myShutterCallback = new ShutterCallback()
    {

        public void onShutter() {
            // TODO Auto-generated method stub
            Log.i(tag, "myShutterCallback:onShutter...");

        }
    };
    PictureCallback myRawCallback = new PictureCallback()
    {

        public void onPictureTaken(byte[] data, Camera camera) {
            // TODO Auto-generated method stub
            Log.i(tag, "myRawCallback:onPictureTaken...");

        }
    };
    PictureCallback myJpegCallback = new PictureCallback()
    {

        public void onPictureTaken(byte[] data, Camera camera) {
            // TODO Auto-generated method stub
            Log.i(tag, "myJpegCallback:onPictureTaken...");
            if(null != data){
                mBitmap = BitmapFactory.decodeByteArray(data, 0, data.length);//data鏄�瓧鑺傛暟鎹�紝灏嗗叾瑙ｆ瀽鎴愪綅鍥�                myCamera.stopPreview();
                isPreview = false;
            }
            Matrix matrix = new Matrix();
            matrix.postRotate((float)90.0);
            Bitmap rotaBitmap = Bitmap.createBitmap(mBitmap, 0, 0, mBitmap.getWidth(), mBitmap.getHeight(), matrix, false);
            if(null != rotaBitmap)
            {
                saveJpeg(rotaBitmap);
            }

            myCamera.startPreview();
            isPreview = true;
        }
    };
    public class PhotoOnClickListener implements OnClickListener{

        public void onClick(View v) {
            // TODO Auto-generated method stub
            if(isPreview && myCamera!=null){
                myCamera.takePicture(myShutterCallback, null, myJpegCallback);
            }

        }

    }

    public void saveJpeg(Bitmap bm){
        String savePath = "/mnt/sdcard/rectPhoto/";
        File folder = new File(savePath);
        if(!folder.exists()) {
            folder.mkdir();
        }
        long dataTake = System.currentTimeMillis();
        String jpegName = savePath + dataTake +".jpg";
        Log.i(tag, "saveJpeg:jpegName--" + jpegName);
        //File jpegFile = new File(jpegName);
        try {
            FileOutputStream fout = new FileOutputStream(jpegName);
            BufferedOutputStream bos = new BufferedOutputStream(fout);

            //          Bitmap newBM = bm.createScaledBitmap(bm, 600, 800, false);

            bm.compress(Bitmap.CompressFormat.JPEG, 100, bos);
            bos.flush();
            bos.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block

            e.printStackTrace();
        }
    }


    public class MyOnTouchListener implements OnTouchListener{

        public final  float[] BT_SELECTED=new float[]
                { 2, 0, 0, 0, 2,
                0, 2, 0, 0, 2,
                0, 0, 2, 0, 2,
                0, 0, 0, 1, 0 };

        public final float[] BT_NOT_SELECTED=new float[]
                { 1, 0, 0, 0, 0,
                0, 1, 0, 0, 0,
                0, 0, 1, 0, 0,
                0, 0, 0, 1, 0 };
        public boolean onTouch(View v, MotionEvent event) {
            // TODO Auto-generated method stub
            if(event.getAction() == MotionEvent.ACTION_DOWN){
                v.getBackground().setColorFilter(new ColorMatrixColorFilter(BT_SELECTED));
                v.setBackgroundDrawable(v.getBackground());
            }
            else if(event.getAction() == MotionEvent.ACTION_UP){
                v.getBackground().setColorFilter(new ColorMatrixColorFilter(BT_NOT_SELECTED));
                v.setBackgroundDrawable(v.getBackground());

            }
            return false;
        }

    }

    @Override
    public void onBackPressed()
    {
        // TODO Auto-generated method stub
        super.onBackPressed();
        StandardCamera.this.finish();
    }



    class UpdateThread implements Runnable{

        public void run() {
            // TODO Auto-generated method stub
            while(flag){
                if(myCamera!=null && isPreview)
                    myCamera.autoFocus(myAutoFocusCallback); //鑷�姩鑱氱劍
                myCamera.setOneShotPreviewCallback(StandardCamera.this); //onPreviewFrame閲屼細鎺ュ彈鍒版暟鎹�?           myCamera.stopPreview(); //鍋滄�棰勮�
                flag = false;

                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

    }



    public void onPreviewFrame(byte[] data, Camera camera) {
        // TODO Auto-generated method stub

    }
}

需要注意的有以下几点：

1，为了让程序适用不同的手机，onCreate函数里用如下代码初始化SurfaceView的大小，避免以前写死的方法：

 public void initView(){
  mPreviewSV = (SurfaceView)findViewById(R.id.previewSV);
  WindowManager wm = (WindowManager)getSystemService(Context.WINDOW_SERVICE);
  Display display = wm.getDefaultDisplay();
        LayoutParams lpSV = mPreviewSV.getLayoutParams();
        lpSV.width = display.getWidth();
        lpSV.height = (int) ((float)display.getHeight()*0.75);
        mPreviewSV.setLayoutParams(lpSV);

   mPhotoImgBtn = (ImageButton)findViewById(R.id.photoImgBtn);
  LayoutParams lp = mPhotoImgBtn.getLayoutParams();
  lp.width = 240;
  lp.height = 240;  
  mPhotoImgBtn.setLayoutParams(lp);    
  mPhotoImgBtn.setOnClickListener(new PhotoOnClickListener());
  mPhotoImgBtn.setOnTouchListener(new MyOnTouchListener());
 }

2，关于ZoomBar的代码片段很简短，如下：

   mPhotoImgBtn = (ImageButton)findViewById(R.id.photoImgBtn);
  LayoutParams lp = mPhotoImgBtn.getLayoutParams();
  lp.width = 240;
  lp.height = 240;  
  mPhotoImgBtn.setLayoutParams(lp);    
  mPhotoImgBtn.setOnClickListener(new PhotoOnClickListener());
  mPhotoImgBtn.setOnTouchListener(new MyOnTouchListener());
 }
  //添加ZoomBar
  mZoomBar = (SeekBar)findViewById(R.id.seekbar_zoom);
  mZoomBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
   
   public void onStopTrackingTouch(SeekBar seekBar) {
    // TODO Auto-generated method stub
    
   }
   
   public void onStartTrackingTouch(SeekBar seekBar) {
    // TODO Auto-generated method stub
    
   }
   
   public void onProgressChanged(SeekBar seekBar, int progress,
     boolean fromUser) {
    // TODO Auto-generated method stub
    Parameters p = myCamera.getParameters();
    p.setZoom(progress);
    myCamera.setParameters(p);
   }
  });

3，在initCamera函数里，查询camera支持的聚焦模式，如果带连续视频聚焦则使用连续视频聚焦，否则使用自动聚焦：

   mPhotoImgBtn = (ImageButton)findViewById(R.id.photoImgBtn);
  LayoutParams lp = mPhotoImgBtn.getLayoutParams();
  lp.width = 240;
  lp.height = 240;  
  mPhotoImgBtn.setLayoutParams(lp);    
  mPhotoImgBtn.setOnClickListener(new PhotoOnClickListener());
  mPhotoImgBtn.setOnTouchListener(new MyOnTouchListener());
 }
List<String> focuseMode = (myParam.getSupportedFocusModes());
   for(int i=0; i<focuseMode.size(); i++){
    Log.i(tag, focuseMode.get(i));
    if(focuseMode.get(i).contains("continuous")){
     myParam.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
    }
    else{
     myParam.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
    }
   }

4，同样在initCamera函数里，设置ZoomBar的最大值：
//设置mZoomBar的最大值
   mZoomBar.setMax(myParam.getMaxZoom());

后续将写专文分析Camera4.0的源码，并且模仿到自己的代码中！