2010.11.16———android Camera 拍照的两个问题

2010.11.16———android Camera 拍照的两个问题

1、setParameters failed 异常信息如下

11-16 11:21:33.902: WARN/System.err(27218): java.lang.RuntimeException: setParameters failed11-16 11:21:33.902: WARN/System.err(27218):     at android.hardware.Camera.native_setParameters(Native Method)......

原因在于

parameters.setPreviewSize()//设置预览照片的大小parameters.setPictureSize()//设置照片的大小

这两个属性如果这两个属性设置的和真实手机的不一样时，就会报上面的错误很是郁闷

最好的方法就是不设置这两项

2、java.lang.NullPointerException

11-16 13:33:39.801: ERROR/AndroidRuntime(5676): FATAL EXCEPTION: main11-16 13:33:39.801: ERROR/AndroidRuntime(5676): java.lang.NullPointerException11-16 13:33:39.801: ERROR/AndroidRuntime(5676):     at com.huitu.project.PicActivity.onKeyDown(PicActivity.java:87)11-16 13:33:39.801: ERROR/AndroidRuntime(5676):     at android.view.KeyEvent.dispatch(KeyEvent.java:1257)11-16 13:33:39.801: ERROR/AndroidRuntime(5676):     at android.app.Activity.dispatchKeyEvent(Activity.java:2075)

其实这个原因是因为

@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if(event.getRepeatCount()==0 && camera!=null){switch (keyCode) {case KeyEvent.KEYCODE_SEARCH://按下的是搜索键camera.autoFocus(null);//自动对焦return true;case KeyEvent.KEYCODE_CAMERA:case KeyEvent.KEYCODE_DPAD_CENTER:camera.takePicture(null, null, new MyPictureCallback());Intent data = new Intent();data.putExtra("picFile", picFile.getAbsolutePath());setResult(100, data);finish();return true;}}return super.onKeyDown(keyCode, event);}private final class MyPictureCallback implements PictureCallback{private String name = "pic";public void onPictureTaken(byte[] data, Camera camera) {try {Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);picFile = new File(Environment.getExternalStorageDirectory(), name + System.currentTimeMillis()+".jpg");FileOutputStream outStream = new FileOutputStream(picFile);bitmap.compress(CompressFormat.JPEG, 100, outStream);outStream.close();//camera.startPreview();} catch (Exception e) {e.printStackTrace();}}}

camera.takePicture(null, null, new MyPictureCallback());

这个方法是异步执行的也就是说

new MyPictureCallback()还没有执行完成，

Intent data = new Intent();data.putExtra("picFile", picFile.getAbsolutePath());setResult(100, data);finish();

下面的代码就开始执行了这时候 picFile就是空的所以就会报空指针异常

解决方法把

Intent data = new Intent();data.putExtra("picFile", picFile.getAbsolutePath());setResult(100, data);finish();放到MyPictureCallback()里面 最后执行即可

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