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

1. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
2. xmlns:tools="http://schemas.android.com/tools"
3. android:layout_width="fill_parent"
4. android:layout_height="fill_parent"
5. android:orientation="vertical" >
6. <TextView
7. android:layout_width="wrap_content"
8. android:layout_height="wrap_content"
9. android:text="@string/BestWish"
10. tools:context=".StandardCamera" />
11. <RelativeLayout
12. android:layout_width="wrap_content"
13. android:layout_height="wrap_content" >
14. <FrameLayout
15. android:layout_width="wrap_content"
16. android:layout_height="wrap_content" >
17. <SurfaceView
18. android:id="@+id/previewSV"
19. android:layout_width="fill_parent"
20. android:layout_height="wrap_content" />
21. </FrameLayout>
22. <LinearLayout
23. android:id="@+id/zoomLayout"
24. android:layout_width="wrap_content"
25. android:layout_height="40dp"
26. android:layout_centerInParent="true"
27. android:layout_centerHorizontal="true"
28. android:orientation="horizontal" >
29. <TextView
30. android:id="@+id/textView1"
31. android:layout_width="wrap_content"
32. android:layout_height="wrap_content"
33. android:text="-"
34. android:textColor="#ffffff"
35. android:textSize="30dip"/>
36. <SeekBar
37. android:id="@+id/seekbar_zoom"
38. android:layout_width="300dp"
39. android:layout_height="wrap_content"
40. android:layout_gravity="center_vertical"
41. android:progressDrawable="@drawable/seekbar_style"
42. android:thumb="@drawable/ic_launcher"
43. android:thumbOffset="0dp" />
44. <TextView
45. android:id="@+id/textView2"
46. android:layout_width="wrap_content"
47. android:layout_height="wrap_content"
48. android:text="+"
49. android:textColor="#ffffff"
50. android:textSize="30dip" />
51. </LinearLayout>
52. </RelativeLayout>
53. <ImageButton
54. android:id="@+id/photoImgBtn"
55. android:layout_width="wrap_content"
56. android:layout_height="wrap_content"
57. android:layout_gravity="center"
58. android:background="@drawable/photo_img_btn" />
59. </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：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <layer-list xmlns:android="http://schemas.android.com/apk/res/android">
3. <item android:id="@android:id/background">
4. <shape>
5. <corners android:radius="5dip" />
6. <gradient
7. android:startColor="#ff9d9e9d"
8. android:centerColor="#ff5a5d5a"
9. android:centerY="0.75"
10. android:endColor="#ff747674"
11. android:angle="270"
12. />
13. </shape>
14. </item>
15. </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：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <selector xmlns:android="http://schemas.android.com/apk/res/android">
3. <!-- 按下状态 -->
4. <item android:state_focused="true" android:state_pressed="true"><shape android:shape="oval">
5. <gradient android:angle="0" android:centerColor="#FF00FF00" android:endColor="#000000" android:gradientRadius="8" android:startColor="#FFFF0000" android:type="radial" />
6. <size android:height="20dip" android:width="20dip"></size>
7. </shape></item>
8. </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：

1. package yan.guoqi.camera;
2. import java.io.BufferedOutputStream;
3. import java.io.File;
4. import java.io.FileOutputStream;
5. import java.io.IOException;
6. import java.util.List;
7. import yan.guoqi.rectphoto.R;
8. import android.app.Activity;
9. import android.content.Context;
10. import android.graphics.Bitmap;
11. import android.graphics.BitmapFactory;
12. import android.graphics.ColorMatrixColorFilter;
13. import android.graphics.Matrix;
14. import android.graphics.PixelFormat;
15. import android.hardware.Camera;
16. import android.hardware.Camera.AutoFocusCallback;
17. import android.hardware.Camera.Parameters;
18. import android.hardware.Camera.PictureCallback;
19. import android.hardware.Camera.PreviewCallback;
20. import android.hardware.Camera.ShutterCallback;
21. import android.os.Bundle;
22. import android.util.Log;
23. import android.view.Display;
24. import android.view.MotionEvent;
25. import android.view.SurfaceHolder;
26. import android.view.SurfaceView;
27. import android.view.View;
28. import android.view.View.OnClickListener;
29. import android.view.View.OnTouchListener;
30. import android.view.ViewGroup.LayoutParams;
31. import android.view.Window;
32. import android.view.WindowManager;
33. import android.widget.ImageButton;
34. import android.widget.SeekBar;
35. import android.widget.SeekBar.OnSeekBarChangeListener;
36. public class StandardCamera extends Activity implements SurfaceHolder.Callback, PreviewCallback{
37. private static final String tag="StandardCamera";
38. private boolean isPreview = false;
39. private SurfaceView mPreviewSV = null; //棰勮SurfaceView
40. private SurfaceHolder mySurfaceHolder = null;
41. private ImageButton mPhotoImgBtn = null;
42. private Camera myCamera = null;
43. private Bitmap mBitmap = null;
44. private AutoFocusCallback myAutoFocusCallback = null;
45. boolean flag = true;
46. private SeekBar mZoomBar = null;
47. @Override
48. public void onCreate(Bundle savedInstanceState) {
49. super.onCreate(savedInstanceState);
50. requestWindowFeature(Window.FEATURE_NO_TITLE);
51. int flag = WindowManager.LayoutParams.FLAG_FULLSCREEN;
52. Window myWindow = this.getWindow();
53. myWindow.setFlags(flag, flag);
54. setContentView(R.layout.activity_rect_photo);
55. initView();
56. mySurfaceHolder = mPreviewSV.getHolder();
57. mySurfaceHolder.setFormat(PixelFormat.TRANSLUCENT);
58. mySurfaceHolder.addCallback(this);
59. mySurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
60. myAutoFocusCallback = new AutoFocusCallback() {
61. public void onAutoFocus(boolean success, Camera camera) {
62. // TODO Auto-generated method stub
63. if(success)
64. {
65. Log.i(tag, "myAutoFocusCallback: success...");
66. }
67. else
68. {
69. Log.i(tag, "myAutoFocusCallback: 澶辫触浜�?.");
70. }
71. }
72. };
73. //添加ZoomBar
74. mZoomBar = (SeekBar)findViewById(R.id.seekbar_zoom);
75. mZoomBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
76. public void onStopTrackingTouch(SeekBar seekBar) {
77. // TODO Auto-generated method stub
78. }
79. public void onStartTrackingTouch(SeekBar seekBar) {
80. // TODO Auto-generated method stub
81. }
82. public void onProgressChanged(SeekBar seekBar, int progress,
83. boolean fromUser) {
84. // TODO Auto-generated method stub
85. Parameters p = myCamera.getParameters();
86. p.setZoom(progress);
87. myCamera.setParameters(p);
88. }
89. });
90. }
91. public void initView(){
92. mPreviewSV = (SurfaceView)findViewById(R.id.previewSV);
93. WindowManager wm = (WindowManager)getSystemService(Context.WINDOW_SERVICE);
94. Display display = wm.getDefaultDisplay();
95. LayoutParams lpSV = mPreviewSV.getLayoutParams();
96. lpSV.width = display.getWidth();
97. lpSV.height = (int) ((float)display.getHeight()*0.75);
98. mPreviewSV.setLayoutParams(lpSV);
99. mPhotoImgBtn = (ImageButton)findViewById(R.id.photoImgBtn);
100. LayoutParams lp = mPhotoImgBtn.getLayoutParams();
101. lp.width = 240;
102. lp.height = 240;
103. mPhotoImgBtn.setLayoutParams(lp);
104. mPhotoImgBtn.setOnClickListener(new PhotoOnClickListener());
105. mPhotoImgBtn.setOnTouchListener(new MyOnTouchListener());
106. }
107. public void surfaceChanged(SurfaceHolder holder, int format, int width,int height)
108. {
109. // TODO Auto-generated method stub
110. Log.i(tag, "SurfaceHolder.Callback:surfaceChanged!");
111. initCamera();
112. }
113. public void surfaceCreated(SurfaceHolder holder)
114. {
115. // TODO Auto-generated method stub
116. myCamera = Camera.open();
117. try {
118. myCamera.setPreviewDisplay(mySurfaceHolder);
119. Log.i(tag, "SurfaceHolder.Callback: surfaceCreated!");
120. } catch (IOException e) {
121. // TODO Auto-generated catch block
122. if(null != myCamera){
123. myCamera.release();
124. myCamera = null;
125. }
126. e.printStackTrace();
127. }
128. }
129. public void surfaceDestroyed(SurfaceHolder holder)
130. {
131. // TODO Auto-generated method stub
132. Log.i(tag, "SurfaceHolder.Callback锛歋urface Destroyed");
133. if(null != myCamera)
134. {
135. myCamera.setPreviewCallback(null);
136. myCamera.stopPreview();
137. isPreview = false;
138. myCamera.release();
139. myCamera = null;
140. }
141. }
142. public void initCamera(){
143. if(isPreview){
144. myCamera.stopPreview();
145. }
146. if(null != myCamera){
147. Camera.Parameters myParam = myCamera.getParameters();
148. myParam.setPictureFormat(PixelFormat.JPEG);//璁剧疆鎷嶇収鍚庡瓨鍌ㄧ殑鍥剧墖鏍煎紡
149. //List<Size> pictureSizes = myParam.getSupportedPictureSizes();
150. //List<Size> previewSizes = myParam.getSupportedPreviewSizes();
151. //          for(int i=0; i<pictureSizes.size(); i++){
152. //              Size size = pictureSizes.get(i);
153. //              Log.i(tag, "initCamera:pictureSizes: width = "+size.width+"height = "+size.height);
154. //          }
155. //          for(int i=0; i<previewSizes.size(); i++){
156. //              Size size = previewSizes.get(i);
157. //              Log.i(tag, "initCamera:鎽勫儚澶存敮鎸佺殑previewSizes: width = "+size.width+"height = "+size.height);
158. //
159. //          }
160. myParam.setPictureSize(1280, 960);  //
161. myParam.setPreviewSize(960, 720);   //
162. //myParam.set("rotation", 90);
163. myCamera.setDisplayOrientation(90);
164. List<String> focuseMode = (myParam.getSupportedFocusModes());
165. for(int i=0; i<focuseMode.size(); i++){
166. Log.i(tag, focuseMode.get(i));
167. if(focuseMode.get(i).contains("continuous")){
168. myParam.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
169. }
170. else{
171. myParam.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
172. }
173. }
174. //设置mZoomBar的最大值
175. mZoomBar.setMax(myParam.getMaxZoom());
176. myCamera.setParameters(myParam);
177. myCamera.startPreview();
178. myCamera.autoFocus(myAutoFocusCallback);
179. isPreview = true;
180. }
181. }
182. ShutterCallback myShutterCallback = new ShutterCallback()
183. {
184. public void onShutter() {
185. // TODO Auto-generated method stub
186. Log.i(tag, "myShutterCallback:onShutter...");
187. }
188. };
189. PictureCallback myRawCallback = new PictureCallback()
190. {
191. public void onPictureTaken(byte[] data, Camera camera) {
192. // TODO Auto-generated method stub
193. Log.i(tag, "myRawCallback:onPictureTaken...");
194. }
195. };
196. PictureCallback myJpegCallback = new PictureCallback()
197. {
198. public void onPictureTaken(byte[] data, Camera camera) {
199. // TODO Auto-generated method stub
200. Log.i(tag, "myJpegCallback:onPictureTaken...");
201. if(null != data){
202. 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();
203. isPreview = false;
204. }
205. Matrix matrix = new Matrix();
206. matrix.postRotate((float)90.0);
207. Bitmap rotaBitmap = Bitmap.createBitmap(mBitmap, 0, 0, mBitmap.getWidth(), mBitmap.getHeight(), matrix, false);
208. if(null != rotaBitmap)
209. {
210. saveJpeg(rotaBitmap);
211. }
212. myCamera.startPreview();
213. isPreview = true;
214. }
215. };
216. public class PhotoOnClickListener implements OnClickListener{
217. public void onClick(View v) {
218. // TODO Auto-generated method stub
219. if(isPreview && myCamera!=null){
220. myCamera.takePicture(myShutterCallback, null, myJpegCallback);
221. }
222. }
223. }
224. public void saveJpeg(Bitmap bm){
225. String savePath = "/mnt/sdcard/rectPhoto/";
226. File folder = new File(savePath);
227. if(!folder.exists()) {
228. folder.mkdir();
229. }
230. long dataTake = System.currentTimeMillis();
231. String jpegName = savePath + dataTake +".jpg";
232. Log.i(tag, "saveJpeg:jpegName--" + jpegName);
233. //File jpegFile = new File(jpegName);
234. try {
235. FileOutputStream fout = new FileOutputStream(jpegName);
236. BufferedOutputStream bos = new BufferedOutputStream(fout);
237. //          Bitmap newBM = bm.createScaledBitmap(bm, 600, 800, false);
238. bm.compress(Bitmap.CompressFormat.JPEG, 100, bos);
239. bos.flush();
240. bos.close();
241. } catch (IOException e) {
242. // TODO Auto-generated catch block
243. e.printStackTrace();
244. }
245. }
246. public class MyOnTouchListener implements OnTouchListener{
247. public final  float[] BT_SELECTED=new float[]
248. { 2, 0, 0, 0, 2,
249. 0, 2, 0, 0, 2,
250. 0, 0, 2, 0, 2,
251. 0, 0, 0, 1, 0 };
252. public final float[] BT_NOT_SELECTED=new float[]
253. { 1, 0, 0, 0, 0,
254. 0, 1, 0, 0, 0,
255. 0, 0, 1, 0, 0,
256. 0, 0, 0, 1, 0 };
257. public boolean onTouch(View v, MotionEvent event) {
258. // TODO Auto-generated method stub
259. if(event.getAction() == MotionEvent.ACTION_DOWN){
260. v.getBackground().setColorFilter(new ColorMatrixColorFilter(BT_SELECTED));
261. v.setBackgroundDrawable(v.getBackground());
262. }
263. else if(event.getAction() == MotionEvent.ACTION_UP){
264. v.getBackground().setColorFilter(new ColorMatrixColorFilter(BT_NOT_SELECTED));
265. v.setBackgroundDrawable(v.getBackground());
266. }
267. return false;
268. }
269. }
270. @Override
271. public void onBackPressed()
272. {
273. // TODO Auto-generated method stub
274. super.onBackPressed();
275. StandardCamera.this.finish();
276. }
277. class UpdateThread implements Runnable{
278. public void run() {
279. // TODO Auto-generated method stub
280. while(flag){
281. if(myCamera!=null && isPreview)
282. myCamera.autoFocus(myAutoFocusCallback); //鑷姩鑱氱劍
283. myCamera.setOneShotPreviewCallback(StandardCamera.this); //onPreviewFrame閲屼細鎺ュ彈鍒版暟鎹�?           myCamera.stopPreview(); //鍋滄棰勮
284. flag = false;
285. try {
286. Thread.sleep(1000);
287. } catch (InterruptedException e) {
288. // TODO Auto-generated catch block
289. e.printStackTrace();
290. }
291. }
292. }
293. }
294. public void onPreviewFrame(byte[] data, Camera camera) {
295. // TODO Auto-generated method stub
296. }
297. }

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！