我已经构建了一个应用程序,当您触摸预览时拍摄照片.
我可以拍摄很多照片,但有时候,当我触摸预览拍摄照片时,没有快门音,整个应用程序冻结.此外,在此之后,如果我尝试启动内置相机应用程序,我会收到一条消息,指出相机不能使用.
我可以拍摄很多照片,但有时候,当我触摸预览拍摄照片时,没有快门音,整个应用程序冻结.此外,在此之后,如果我尝试启动内置相机应用程序,我会收到一条消息,指出相机不能使用.
我不知道这个行为的原因,它是随机发生的,当它发生时,我必须重新启动设备(Samsung Galaxy S)才能再次使用相机.
在DDM中,崩溃后我可以看到以下行：keyDispatchingTimedOut
以下是相关代码：
CameraActivity类：
public class CameraActivity extends Activity {
private static final String TAG = "CameraDemo";
Preview preview;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
preview = new Preview(this);
((FrameLayout) findViewById(R.id.preview)).addView(preview);
((FrameLayout) findViewById(R.id.preview)).setOnTouchListener(preview);
Log.d(TAG,"Camera Activity Created.");
}
}
预览课程：
class Preview extends SurfaceView implements SurfaceHolder.Callback,OnTouchListener {
private static final String TAG = "Preview";
SurfaceHolder mHolder;
public Camera camera;
Context ctx;
boolean previewing = false;
Preview(Context context) {
super(context);
ctx = context;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
// Called once the holder is ready
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created,acquire the camera and tell it where
// to draw.
camera = Camera.open();
}
// Called when the holder is destroyed
public void surfaceDestroyed(SurfaceHolder holder) {
if (camera != null) {
camera.setPreviewCallback(null);
camera.stopPreview();
camera.release();
camera = null;
}
previewing = false;
}
// Called when holder has changed
public void surfaceChanged(SurfaceHolder holder,int format,int w,int h) {
if(previewing){
camera.stopPreview();
previewing = false;
}
if (camera != null){
try {
camera.setDisplayOrientation(90);
camera.setPreviewDisplay(holder);
camera.setPreviewCallback(new PreviewCallback() {
// Called for each frame previewed
public void onPreviewFrame(byte[] data,Camera camera) {
Log.d(TAG,"onPreviewFrame called at: " + System.currentTimeMillis());
Preview.this.invalidate();
}
});
camera.startPreview();
previewing = true;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public boolean onTouch(View v,MotionEvent event) {
camera.takePicture(shutterCallback,rawCallback,jpegCallback);
return false;
}
// Called when shutter is opened
ShutterCallback shutterCallback = new ShutterCallback() {
public void onShutter() {
Log.d(TAG,"onShutter'd");
}
};
// Handles data for raw picture
PictureCallback rawCallback = new PictureCallback() {
public void onPictureTaken(byte[] data,Camera camera) {
Log.d(TAG,"onPictureTaken - raw");
}
};
// Handles data for jpeg picture
PictureCallback jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data,Camera camera) {
FileOutputStream outStream = null;
try {
// Write to SD Card
outStream = new FileOutputStream(String.format("/sdcard/TVguide/Detection/detected.jpg",System.currentTimeMillis())); // <9>
outStream.write(data);
outStream.close();
Log.d(TAG,"onPictureTaken - wrote bytes: " + data.length);
} catch (FileNotFoundException e) { // <10>
//Toast.makeText(ctx,"Exception #2",Toast.LENGTH_LONG).show();
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {}
Log.d(TAG,"onPictureTaken - jpeg");
Toast.makeText(ctx,"SAVED",Toast.LENGTH_SHORT).show();
camera.startPreview();
}
};
}
请帮忙,我正在尝试几天,了解问题在哪里,没有成功
的Eyal
解决方法
我不知道是什么原因导致这个错误,如果从发生此错误的时间发布了loggcat输出,这将真的有帮助.
但是,我可以做一些gusesses.看起来相机被锁定(内置相机不起作用).如果您的应用程序强制关闭,相机锁定可能是由于Samsung相机HAL中的错误处理引起的.特别是在像Galaxy S这样的老旧手机中,他们在处理错误或者不是标准的API调用时都没有做最好的工作.
以下是可能导致此行为的一些建议：
>你应该添加一个护照来拍摄.现在,如果您触摸屏幕并拍摄照片,则可以在照片拍摄完成之前再次触摸屏幕.所以,camera.takePicture()将被调用两次.第二个会失败.这是我最好的猜测.
添加一些布尔值isTakingPicture = false变量然后：
public boolean onTouch(View v,MotionEvent event) {
if (!isTakingPicture) {
camera.takePicture(shutterCallback,jpegCallback);
isTakingPicture = true;
}
return false;
}
...
public void onPictureTaken(byte[] data,Camera camera) {
isTakingPicture = false;
...
>你使用previewCallback做什么？我在这里没有任何有用的东西.有时候,预览回调有时会导致一些痛苦,尽管你的代码对我来说看起来不错.你可以试试删除它,并检查是否有帮助.
