Android深入探究-- 实现即时拍照并上传
使用摄像头拍照
?
1. 使用 SurfaceView 控件来显示摄像头捕捉到的画面
?????? <SurfaceView android:layout_width="fill_parent" android:layout_height="240dip" android:id="@+id/surfaceView" />
?
2. 具体细节
?????? /* 获取 SurfaceView 控件 */
?????? SurfaceView surfaceView = (SurfaceView)this.findViewById(R.id.surfaceView);
?????? /* 设置分辨率 */
?????? surfaceView.getHolder().setFixedSize(176, 144);
?????? /*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/
?????? surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
?????? /* 打开摄像头，注意这里是 android.hardware.Camera */
?????? Camera camera = Camera.open();
?????
?????? /* 为 Camera 设置摄像参数 */
?????? Camera.Parameters parameters = camera.getParameters();
?????
?????? /* 设置预览照片的大小，此处设置为全屏 */
?????? WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE); // 获取当前屏幕管理器对象
?????? Display display = wm.getDefaultDisplay();????????????????????????????????????? // 获取屏幕信息的描述类
?????? parameters.setPreviewSize(display.getWidth(), display.getHeight());????????? // 设置
?????
?????? /* 每秒从摄像头捕获5帧画面， */
?????? parameters.setPreviewFrameRate(5);
?????? /* 设置照片的输出格式:jpg */
?????? parameters.setPictureFormat(PixelFormat.JPEG);
?????? /* 照片质量 */
?????? parameters.set("jpeg-quality", 85);
?????? /* 设置照片的大小：此处照片大小等于屏幕大小 */
?????? parameters.setPictureSize(display.getWidth(), display.getHeight());
?????? /* 将参数对象赋予到 camera 对象上 */
?????? camera.setParameters(parameters);
?????
?????? /* 设置用 SurfaceView 作为承载镜头取景画面的显示 */
?????? camera.setPreviewDisplay(surfaceView.getHolder());
?????? /* 开始预览 */
?????? camera.startPreview();
?????? /* 自动对焦 */
?????? camera.autoFocus(null);
?????? /* 拍照片 */
?????? camera.takePicture(null, null, null, jpegCallback);
?????? /* 停止预览 */
?????? camera.stopPreview();
?????? /* 释放摄像头 */
?????? camera.release();
?
3. 添加使用摄像头的权限
?????? <uses-permission android:name="android.permission.CAMERA"/>
?
4. 测试: 目前模拟器不支持拍照环境的模拟，必须使用真实手机测试。
?
5. 代码清单
?????? ** string values : strings.xml
???????????? view plaincopy to clipboardprint?
<?xml version="1.0" encoding="utf-8"?>?
<resources>?
??? <string name="app_name">手机拍照程序</string>?
</resources>?
<?xml version="1.0" encoding="utf-8"?>
<resources>
??? <string name="app_name">手机拍照程序</string>
</resources>
?????
?????? ** AndroidManifest.xml
???????????? view plaincopy to clipboardprint?
<?xml version="1.0" encoding="utf-8"?>?
<manifest xmlns:android="http://schemas.android.com/apk/res/android"?
????? package="wjh.android.takepicture"?
????? android:versionCode="1"?
????? android:versionName="1.0">?
??? <application android:icon="@drawable/icon" android:label="@string/app_name">?
??????? <!-- android:screenOrientation="landscape" 表示横向界面 -->?
??????? <activity android:name=".MainActicity" android:label="@string/app_name"? android:screenOrientation="landscape">?
??????????? <intent-filter>?
??????????????? <action android:name="android.intent.action.MAIN" />?
??????????????? <category android:name="android.intent.category.LAUNCHER" />?
??????????? </intent-filter>?
??????? </activity>?
??? </application>?
??? <uses-sdk android:minSdkVersion="8" />?
??? <!-- 在SDCard中创建与删除文件权限 -->?
??? <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>?
??? <!-- 往SDCard写入数据权限 -->?
??? <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>?
??? <!-- 申请使用摄像头的权限 -->?
??? <uses-permission android:name="android.permission.CAMERA"/>?
</manifest>?
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
????? package="wjh.android.takepicture"
????? android:versionCode="1"
????? android:versionName="1.0">
??? <application android:icon="@drawable/icon" android:label="@string/app_name">
???? <!-- android:screenOrientation="landscape" 表示横向界面 -->
??????? <activity android:name=".MainActicity" android:label="@string/app_name"? android:screenOrientation="landscape">
??????????? <intent-filter>
??????????????? <action android:name="android.intent.action.MAIN" />
??????????????? <category android:name="android.intent.category.LAUNCHER" />
??????????? </intent-filter>
??????? </activity>
??? </application>
??? <uses-sdk android:minSdkVersion="8" />
??? <!-- 在SDCard中创建与删除文件权限 -->
?<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
?<!-- 往SDCard写入数据权限 -->
?<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
??? <!-- 申请使用摄像头的权限 -->
?<uses-permission android:name="android.permission.CAMERA"/>
</manifest>
?
?????
?????? ** main.xml
???????????? view plaincopy to clipboardprint?
<?xml version="1.0" encoding="utf-8"?>?
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"?
??? android:orientation="vertical"?
??? android:layout_width="fill_parent"?
??? android:layout_height="fill_parent"?
??? >?
<SurfaceView android:id="@+id/surfaceView"?
??? android:layout_width="fill_parent"???
??? android:layout_height="fill_parent"???
??? />?
??????
</LinearLayout>?
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
??? android:orientation="vertical"
??? android:layout_width="fill_parent"
??? android:layout_height="fill_parent"
??? >
<SurfaceView android:id="@+id/surfaceView"
??? android:layout_width="fill_parent"
??? android:layout_height="fill_parent"
??? />
???
</LinearLayout>
?
?????
?????? ** MainActicity
????????????? view plaincopy to clipboardprint?
public class MainActicity extends Activity {??
??? private Camera camera;???
??? private boolean preview? = false ;??
??? @Override?
??? public void onCreate(Bundle savedInstanceState) {??
??????? super.onCreate(savedInstanceState);??
??????????
??????? /*?
???????? *设置窗口属性：一定要在 setContentView(R.layout.main) 之前?
???????? */?
??????? // 窗口标题??
??????? requestWindowFeature(Window.FEATURE_NO_TITLE);??
??????? // 全屏???
??????? getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);??
??????????
??????? setContentView(R.layout.main);??
??????????
?????? SurfaceView surfaceView =? (SurfaceView) findViewById(R.id.surfaceView);??
?????? surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);??
?????? surfaceView.getHolder().setFixedSize(176, 164);??
?????????
?????? surfaceView.getHolder().addCallback(new SurfaceViewCallback());??
??? }??
??????
??? private final class SurfaceViewCallback implements Callback {??
??????? /**?
???????? * surfaceView 被创建成功后调用此方法?
???????? */?
??????? @Override?
??????? public void surfaceCreated(SurfaceHolder holder) {??
??????????? /*??
???????????? * 在SurfaceView创建好之后 打开摄像头?
???????????? * 注意是 android.hardware.Camera?
???????????? */?
??????????? camera = Camera.open();??
??????????? Camera.Parameters parameters = camera.getParameters();??
??????????? /* 设置预览照片的大小，此处设置为全屏 */?
??????????? WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE); // 获取当前屏幕管理器对象??
??????????? Display display = wm.getDefaultDisplay();??????????????????????? // 获取屏幕信息的描述类??
??????????? parameters.setPreviewSize(display.getWidth(), display.getHeight());????????? // 设置??
??????????????
??????????? /* 每秒从摄像头捕获5帧画面， */?
??????????? parameters.setPreviewFrameRate(5);??
??????????? /* 设置照片的输出格式:jpg */?
??????????? parameters.setPictureFormat(PixelFormat.JPEG);??
??????????? /* 照片质量 */?
??????????? parameters.set("jpeg-quality", 85);??
??????????? /* 设置照片的大小：此处照片大小等于屏幕大小 */?
??????????? parameters.setPictureSize(display.getWidth(), display.getHeight());??
??????????? /* 将参数对象赋予到 camera 对象上 */?
??????????? camera.setParameters(parameters);??
??????????? preview = true;??
??????? }??
??????? @Override?
??????? public void surfaceChanged(SurfaceHolder holder, int format, int width,??
??????????????? int height) {??
??????? }??
??????? /**?
???????? * SurfaceView 被销毁时释放掉 摄像头?
???????? */?
??????? @Override?
??????? public void surfaceDestroyed(SurfaceHolder holder) {??
??????????? if(camera != null) {??
??????????????? /* 若摄像头正在工作，先停止它 */?
??????????????? if(preview) {??
??????????????????? camera.stopPreview();??
??????????????????? preview = false;??
??????????????? }?????????
??????????????? camera.release();??
??????????? }??
??????? }??
??????????
??? }??
??????
??????
??? /**?
???? * 手机键盘按键事件?
???? * 返回 true, 将阻止事件继续传递,例如搜索键，他默认会触发和打开系统的搜索引擎。返回true后，将不会触发。?
???? */?
??? @Override?
??? public boolean onKeyDown(int keyCode, KeyEvent event) {??
??????? /*?
???????? * event.getRepeatCount() 为重复按键的次数，例如，快速地对某个键连续按了两次，则此值为一，表示重复了一次。往上可以累推。?
???????? * 按键只被按了一次，则此值为 0。?
???????? * 这有点类似于鼠标的 "单击" 和 "双击"。?
???????? */?
??????? if(camera != null && event.getRepeatCount() == 0 ) {??
??????????? switch (keyCode) {??
??????????? case KeyEvent.KEYCODE_SEARCH: // 搜索键??
??????????????? /* 按下搜索键自动对焦 , 如果要关注它的事件，?
???????????????? * 可以实现 AutoFocusCallback 接口，并实例化其对象传入 */?
??????????????? camera.autoFocus(null);??
??????????????? break;??
??????????? case KeyEvent.KEYCODE_CAMERA: // 拍照键??
??????????? case KeyEvent.KEYCODE_DPAD_CENTER: // 中间确认键??
??????????????? /*?
???????????????? * @param shutter : 照片被捕获之后的回调对象?
???????????????? * @param raw : 此回调对象可以生产为压缩的图片数据?
???????????????? * @param jpeg : 此回调对象可以产生压缩后的图片数据，其onPictureTaken将被调用?
???????????????? */?
??????????????? camera.takePicture(null, null, new TakePictureCallback());??
??????????????????
??????????????? /* 拍完照后回到预览状态，继续取景 -- 错误的方式 */?
??????????????? // camera.startPreview();必须写在 onPictureTaken 方法内部，因为 takePicture 内部是另开了一条线程异步的完成保存照片等操作。??
??????????????? // 虽然 takePicture 方法完成了，但是并不代表其内部的工作全部完成，也不代表摄像头以及从上一次“拍照”任务中工作完毕??
??????????????? break;??
??????????? default:??
??????????????? break;??
??????????? }??
??????????? return true;??
??????? }??
??????????
??????? return super.onKeyDown(keyCode, event);??
??? }??
??????
??? /**?
???? * 处理照片被拍摄之后的事件?
???? */?
??? private final class TakePictureCallback implements PictureCallback {??
??????? @Override?
??????? public void onPictureTaken(byte[] data, Camera camera) {??
??????????? Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);??
??????????????
??????????? /* 照片将被保存到? SD 卡跟目录下，文件名为系统时间，后缀名为".jpg" */?
??????????? File file = new File(Environment.getExternalStorageState(), System.currentTimeMillis() + ".jpg");??
??????????? try {??
??????????????? FileOutputStream fos = new FileOutputStream(file);??
??????????????????
??????????????? /* 位图格式为JPEG?
???????????????? * 参数二位 0-100 的数值，100为最大值，表示无损压缩??
???????????????? * 参数三传入一个输出流对象，将图片数据输出到流中??
???????????????? */?
??????????????? bitmap.compress(CompressFormat.JPEG, 100, fos);??
??????????????? fos.close();??
??????????????????
??????????????? /* 拍完照后回到预览状态，继续取景 */?
??????????????? camera.startPreview();??
??????????? } catch (IOException e) {??
??????????????? e.printStackTrace();??
??????????? }??
??????? }??
??? }??
}
?
?
本文来自CSDN博客，出处：http://blog.csdn.net/hwl1314/archive/2011/04/16/6327565.aspx
