活动释放片段 [英] Activity Releasing Fragment
本文介绍了活动释放片段的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个在Fragment中运行的自定义相机.调用OnPictureTaken函数时，Activity会释放Fragment，因此getActivity返回NULL并显示"Fragment Not Attached To Activity".
I have a custom camera running in a Fragment. When the OnPictureTaken function is called the Activity releases the Fragment hence getActivity is returning NULL and "Fragment Not Attached To Activity".
成功拍摄照片.onPictureTaken被调用.我要在那里开始一个活动.
As the picture is successfully taken. onPictureTaken is called. There I want to start an Activity.
@Override
public void onAttach(Context context) {
super.onAttach(context);
mOrientationListener = new CameraOrientationListener(context);
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
mOrientationListener = new CameraOrientationListener(activity);
activity2 = activity;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Restore your state here because a double rotation with this fragment
// in the backstack will cause improper state restoration
// onCreate() -> onSavedInstanceState() instead of going through onCreateView()
if (savedInstanceState == null) {
mCameraID = getBackCameraID();
mFlashMode = CameraSettingPreferences.getCameraFlashMode(getActivity());
mImageParameters = new ImageParameters();
} else {
mCameraID = savedInstanceState.getInt(CAMERA_ID_KEY);
mFlashMode = savedInstanceState.getString(CAMERA_FLASH_KEY);
mImageParameters = savedInstanceState.getParcelable(IMAGE_INFO);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.squarecamera__fragment_camera_demo, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mOrientationListener.enable();
mPreviewView = (SquareCameraPreview) view.findViewById(R.id.camera_preview_view);
mPreviewView.getHolder().addCallback(CameraFragment.this);
final View topCoverView = view.findViewById(R.id.cover_top_view);
final View btnCoverView = view.findViewById(R.id.cover_bottom_view);
mImageParameters.mIsPortrait =
getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT;
if (savedInstanceState == null) {
ViewTreeObserver observer = mPreviewView.getViewTreeObserver();
observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
mImageParameters.mPreviewWidth = mPreviewView.getWidth();
mImageParameters.mPreviewHeight = mPreviewView.getHeight();
mImageParameters.mCoverWidth = mImageParameters.mCoverHeight
= mImageParameters.calculateCoverWidthHeight();
// Log.d(TAG, "parameters: " + mImageParameters.getStringValues());
// Log.d(TAG, "cover height " + topCoverView.getHeight());
resizeTopAndBtmCover(topCoverView, btnCoverView);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
mPreviewView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
} else {
mPreviewView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
}
});
} else {
if (mImageParameters.isPortrait()) {
topCoverView.getLayoutParams().height = mImageParameters.mCoverHeight;
btnCoverView.getLayoutParams().height = mImageParameters.mCoverHeight;
} else {
topCoverView.getLayoutParams().width = mImageParameters.mCoverWidth;
btnCoverView.getLayoutParams().width = mImageParameters.mCoverWidth;
}
}
final ImageView swapCameraBtn = (ImageView) view.findViewById(R.id.change_camera);
swapCameraBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mCameraID == CameraInfo.CAMERA_FACING_FRONT) {
mCameraID = getBackCameraID();
} else {
mCameraID = getFrontCameraID();
}
restartPreview();
}
});
final View changeCameraFlashModeBtn = view.findViewById(R.id.flash);
changeCameraFlashModeBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mFlashMode.equalsIgnoreCase(Camera.Parameters.FLASH_MODE_AUTO)) {
mFlashMode = Camera.Parameters.FLASH_MODE_ON;
} else if (mFlashMode.equalsIgnoreCase(Camera.Parameters.FLASH_MODE_ON)) {
mFlashMode = Camera.Parameters.FLASH_MODE_OFF;
} else if (mFlashMode.equalsIgnoreCase(Camera.Parameters.FLASH_MODE_OFF)) {
mFlashMode = Camera.Parameters.FLASH_MODE_AUTO;
}
setupFlashMode();
setupCamera();
}
});
final ImageView takePhotoBtn = (ImageView) view.findViewById(R.id.capture_image_button);
takePhotoBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
takePicture();
}
});
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode != Activity.RESULT_OK) return;
switch (requestCode) {
case 1:
Uri imageUri = data.getData();
break;
default:
super.onActivityResult(requestCode, resultCode, data);
}
}
//This is the Function Where it lands after the Picture is taken
/**
* A picture has been taken
* @param data
* @param camera
*/
@Override
public void onPictureTaken(byte[] data, Camera camera) {
rotation = getPhotoRotation();
DisplayPicFragment.newInstance(data, rotation,mImageParameters.createCopy());
startActivity(new Intent(getActivity(), DisplayPicActivity.class));
// if(isAdded()){
// startActivity(new Intent(activity2, DisplayPicActivity.class));
// }
setSafeToTakePhoto(true);
}
推荐答案
在您的 DisplayPicActivity 中，我知道您要显示图片.
From your DisplayPicActivity I understand that you want to display the picture.
有一种解决方法- setPreviewDisplay(SurfaceHolder持有人) .
There is a method for that - setPreviewDisplay (SurfaceHolder holder).
这篇关于活动释放片段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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