我的活动应在纵向模式下显示两个Fragments，在横向模式下显示一个Fragment。在正常状态下一切都很好。但是当我从横向旋转到纵向时，空白UI仅显示。片段都有数据，附加到活动但显示时UI是空白的。检查了许多SO答案但没有解决我的问题。
StepDetailActivity.java：
package com.example.codelabs.baking.ui.activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.widget.FrameLayout;
import android.widget.ImageButton;
import android.widget.Toast;
import com.example.codelabs.baking.R;
import com.example.codelabs.baking.model.Recipe;
import com.example.codelabs.baking.model.Step;
import com.example.codelabs.baking.ui.fragment.StepDetailFragment;
import com.example.codelabs.baking.ui.fragment.VideoPlayerFragment;
import com.example.codelabs.baking.utils.RecipeUtils;
import com.google.android.exoplayer2.SimpleExoPlayer;
import com.google.android.exoplayer2.ui.SimpleExoPlayerView;
public class StepDetailActivity extends AppCompatActivity implements StepDetailFragment.TextClicked {
public static final String EXTRA_STEP_POSITION = "stepclickedPosition";
public static final String EXTRA_RECIPE_ID = "clickedrecipeid";
public static final String KEY_STEP_POSITION = "keystepclickedPosition";
public static final String KEY_RECIPE_ID = "keyclickedrecipeid";
public static final String KEY_VIDEO_PLAYER_FRAGMENT = "keyvideoplayerfragment";
public static final String KEY_STEP_DETAIL_FRAGMENT = "keystepdetailfragment";
FrameLayout fm;
SimpleExoPlayerView playerView;
SimpleExoPlayer player;
ImageButton mPreviousButton;
ImageButton mNextButton;
int currentId, previousId, nextId = 0;
VideoPlayerFragment videoPlayerfragment;
StepDetailFragment stepDetailFragment;
FragmentManager fragmentManager;
FragmentTransaction fragmentTransaction;
private Step mStepObject, mStepObjectBackup;
private Recipe mClickedRecipe, mClickedRecipeBackup;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_step_detail);
Intent stepIntent = getIntent();
mStepObject = mStepObjectBackup = stepIntent.getParcelableExtra(EXTRA_STEP_POSITION);
mClickedRecipe = mClickedRecipeBackup = stepIntent.getParcelableExtra(EXTRA_RECIPE_ID);
getSupportActionBar().setTitle(mClickedRecipe.getmRecipeName());
if (this.getResources().getBoolean(R.bool.isTablet) && RecipeUtils.isLandscape(this)) {
finish();
}
fragmentManager = getSupportFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
if (savedInstanceState == null) {
videoPlayerfragment = new VideoPlayerFragment();
videoPlayerfragment.setmStepObject(mStepObject);
videoPlayerfragment.setMediaUrl(mStepObject.getmVideoUrl());
stepDetailFragment = new StepDetailFragment();
stepDetailFragment.setStepObject(mStepObject);
stepDetailFragment.setStepClickedRecipeObject(mClickedRecipe);
if (!(RecipeUtils.isLandscape(StepDetailActivity.this))) {
fragmentTransaction.replace(R.id.frame_media_playerView, videoPlayerfragment, "video_player_fragment");
fragmentTransaction.replace(R.id.frame_description, stepDetailFragment, "step_detail_fragment");
} else {
fragmentTransaction.replace(R.id.frame_media_playerView, videoPlayerfragment, "video_player_fragment");
}
} else {
mStepObject = savedInstanceState.getParcelable(EXTRA_STEP_POSITION);
mClickedRecipe = savedInstanceState.getParcelable(EXTRA_RECIPE_ID);
if (getSupportFragmentManager().findFragmentByTag("video_player_fragment") != null) {
videoPlayerfragment = (VideoPlayerFragment) getSupportFragmentManager().getFragment(savedInstanceState, KEY_VIDEO_PLAYER_FRAGMENT);
} else {
videoPlayerfragment = new VideoPlayerFragment();
videoPlayerfragment.setmStepObject(mStepObject);
videoPlayerfragment.setMediaUrl(mStepObject.getmVideoUrl());
}
if (getSupportFragmentManager().findFragmentByTag("step_detail_fragment") != null) {
stepDetailFragment = (StepDetailFragment) getSupportFragmentManager().getFragment(savedInstanceState, KEY_STEP_DETAIL_FRAGMENT);
} else {
stepDetailFragment = new StepDetailFragment();
stepDetailFragment.setStepClickedRecipeObject(mClickedRecipe);
stepDetailFragment.setStepObject(mStepObject);
}
if (!(RecipeUtils.isLandscape(StepDetailActivity.this))) {
fragmentTransaction.replace(R.id.frame_media_playerView, videoPlayerfragment);
fragmentTransaction.replace(R.id.frame_description, stepDetailFragment);
} else {
fragmentTransaction.replace(
R.id.frame_media_playerView, videoPlayerfragment);
}
}
fragmentTransaction.commit();
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
if (videoPlayerfragment.isAdded())
getSupportFragmentManager().putFragment(outState, KEY_VIDEO_PLAYER_FRAGMENT, videoPlayerfragment);
if (stepDetailFragment.isAdded())
getSupportFragmentManager().putFragment(outState, KEY_STEP_DETAIL_FRAGMENT, stepDetailFragment);
outState.putParcelable(KEY_STEP_POSITION, mStepObject);
outState.putParcelable(KEY_RECIPE_ID, mClickedRecipe);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
fragmentManager = getSupportFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
if (savedInstanceState.getParcelable(KEY_STEP_POSITION) != null) {
mStepObject = savedInstanceState.getParcelable(KEY_STEP_POSITION);
} else {
mStepObject = mStepObjectBackup;
}
if (savedInstanceState.getParcelable(KEY_RECIPE_ID) != null) {
mClickedRecipe = savedInstanceState.getParcelable(KEY_RECIPE_ID);
} else {
mClickedRecipe = mClickedRecipeBackup;
}
if (getSupportFragmentManager().findFragmentByTag("video_player_fragment") != null) {
videoPlayerfragment = (VideoPlayerFragment) getSupportFragmentManager().getFragment(savedInstanceState, KEY_VIDEO_PLAYER_FRAGMENT);
// videoPlayerfragment.setmStepObject(mStepObject);
// videoPlayerfragment.setMediaUrl(mStepObject.getmVideoUrl());
} else {
videoPlayerfragment = new VideoPlayerFragment();
videoPlayerfragment.setmStepObject(mStepObject);
videoPlayerfragment.setMediaUrl(mStepObject.getmVideoUrl());
}
if (getSupportFragmentManager().findFragmentByTag("step_detail_fragment") != null) {
stepDetailFragment = (StepDetailFragment) getSupportFragmentManager().getFragment(savedInstanceState, KEY_STEP_DETAIL_FRAGMENT);
// stepDetailFragment.setStepClickedRecipeObject(mClickedRecipe);
// stepDetailFragment.setStepObject(mStepObject);
} else {
stepDetailFragment = new StepDetailFragment();
stepDetailFragment.setStepClickedRecipeObject(mClickedRecipe);
stepDetailFragment.setStepObject(mStepObject);
}
if (!(RecipeUtils.isLandscape(StepDetailActivity.this))) {
Toast.makeText(this, "ls elsuu stepid" + mStepObject.getmId(), Toast.LENGTH_LONG).show();
fragmentTransaction.replace(R.id.frame_media_playerView, videoPlayerfragment);
fragmentTransaction.replace(R.id.frame_description, stepDetailFragment);
if (videoPlayerfragment.isAdded()) {
Toast.makeText(this, "vp fragment irukku", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "vp fragment illa", Toast.LENGTH_SHORT).show();
}
//clearBackStack();
if (videoPlayerfragment.isAdded()) {
Toast.makeText(this, "sd fragment irukku", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "sd fragment illa", Toast.LENGTH_SHORT).show();
}
} else {
mStepObject = savedInstanceState.getParcelable(KEY_STEP_POSITION);
mClickedRecipe = savedInstanceState.getParcelable(KEY_RECIPE_ID);
fragmentTransaction.replace(R.id.frame_media_playerView, videoPlayerfragment);
//fragmentTransaction.show(stepDetailFragment);
//clearBackStack();
}
fragmentTransaction.commit();
}
@Override
public void sendVideoUrl(Step mStepooo) {
videoPlayerfragment.trigger(mStepooo.getmVideoUrl());
}
@Override
public void sendDescription(Step mStepObject) {
stepDetailFragment.setDescription(mStepObject.getmDescription());
}
}
Github链接：