Android Camera开发：给摄像头预览界面加个ZoomBar（附完整代码下载）
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
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：
-
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：
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 pictureSizes = myParam.getSupportedPictureSizes();
//List previewSizes = myParam.getSupportedPreviewSizes();
// for(int i=0; i focuseMode = (myParam.getSupportedFocusModes());
for(int i=0; i 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
for(int i=0; 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！
源码下载链接：http://download.csdn.net/detail/yanzi1225627/6421779