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

最新推荐文章于 2023-09-28 15:28:52 发布

最新推荐文章于 2023-09-28 15:28:52 发布 · 387 阅读

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#移动开发 #java

本文介绍了一种通过SeekBar组件实现相机焦距动态调节的方法。利用SeekBar的进度变化来调整相机的焦距，使得预览的画面可以放大或缩小。此外，还详细介绍了如何设置SeekBar的最大值以匹配相机的最大焦距范围。

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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);
}
}