activity 中 TabLayout 内片段的约束问题
Constraint issue with fragments inside TabLayout in activity
我正在尝试在我的应用程序开始时实施分步教程。我创建了 3 个用户可以滚动浏览的片段实例。它们使用 FragmentPagerAdapter 组合，设置并添加到 TabLayout，以便将片段视为选项卡。选项卡指示符被赋予了自定义样式，因此它们显示为点。
我遇到的问题是，在设计视图中一切看起来都很好，但是当在模拟器中部署应用程序时，约束布局没有得到遵守，片段中视图控件的定位和大小最终变为一个不稳定的配置。 activity 仅设置为纵向，因此显示方向不是问题。
这是片段在设计视图中的显示方式：
在 WebView 个实例中加载了 3 个单独的 GIF（出于这个问题的目的，它们是随机的）。
这是模拟器中实际出现的一切：
可以看到，WebView是整个片段的大小，TextView和Button是找不到的，即使WebView 已删除。
这是完整的代码和 Android Studio 项目 与问题相关：https://github.com/mathusummut/WhosebugQuestionCode1
这是最相关的代码：
TutorialActivity.java:
package mathusummut.dabtest;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class TutorialActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tutorial);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
Fragment currentPage = new TutorialFragment();
Bundle currentBundle = new Bundle();
currentBundle.putString("tutorialText", "1. Turn the volume up ↑");
currentBundle.putString("tutorialGif", "file:///android_asset/volume.gif");
currentPage.setArguments(currentBundle);
adapter.addFragment(currentPage, "");
currentPage = new TutorialFragment();
currentBundle = new Bundle();
currentBundle.putString("tutorialText", "2. Grab the phone in one hand...");
currentBundle.putString("tutorialGif", "file:///android_asset/step2.gif");
currentPage.setArguments(currentBundle);
adapter.addFragment(currentPage, "");
currentPage = new TutorialFragment();
currentBundle = new Bundle();
currentBundle.putString("tutorialText", "Dab...");
currentBundle.putString("tutorialGif", "file:///android_asset/step3.gif");
currentPage.setArguments(currentBundle);
adapter.addFragment(currentPage, "");
ViewPager viewPager = findViewById(R.id.viewpager);
viewPager.setOffscreenPageLimit(3);
viewPager.setAdapter(adapter);
((TabLayout) findViewById(R.id.tabs)).setupWithViewPager(viewPager);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId()== android.R.id.home) {
finish();
return true;
} else
return super.onOptionsItemSelected(item);
}
public class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> fragmentList = new ArrayList<>();
private final List<String> fragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
@Override
public int getCount() {
return fragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
fragmentList.add(fragment);
fragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return fragmentTitleList.get(position);
}
}
}
fragment_tutorial.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/black"
tools:context="mathusummut.dabtest.TutorialFragment">
<WebView
android:id="@+id/tutorialGifView"
android:layout_width="330dp"
android:layout_height="346dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="100dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</WebView>
<TextView
android:id="@+id/tutorialTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="36dp"
android:text="Instructions"
android:textAlignment="center"
android:textSize="36sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.502"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/nextButton"
android:layout_width="124dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="456dp"
android:layout_x="69dp"
android:layout_y="386dp"
android:background="@android:color/holo_red_dark"
android:text="Next"
android:textAlignment="center"
android:textAllCaps="false"
android:textSize="24sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
activity_tutorial.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/coordinatorLayout2"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="@+id/appBarLayout2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_constraintBottom_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="@+id/appBarLayout2"
app:layout_constraintTop_toTopOf="@+id/appBarLayout2">
</android.support.v4.view.ViewPager>
<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:tabBackground="@drawable/tab_selector"
app:tabGravity="center"
app:tabMode="fixed"
app:tabIndicatorHeight="0dp"/>
</android.support.constraint.ConstraintLayout>
我试过使用 RelativeLayout 而不是 ConstraintLayout，但更改似乎对结果没有影响。请问我该怎么做才能解决这个问题？
这是您完成我所需更改的代码。
enter image description here
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View currentFragment = inflater.inflate(R.layout.fragment_tutorial, container, false);
WebView view = currentFragment.findViewById(R.id.tutorialGifView);
Bundle passedArguments = getArguments();
((TextView) currentFragment.findViewById(R.id.tutorialTextView)).setText(passedArguments.getString("tutorialText"));
view.loadDataWithBaseURL(null, TEMPLATE_HTML.replace("gif", passedArguments.getString("tutorialGif")), "text/html", "utf-8", null);
view.setBackgroundColor(Color.TRANSPARENT);
view.setInitialScale(1);
view.getSettings().setJavaScriptEnabled(true);
view.getSettings().setLoadWithOverviewMode(true);
view.getSettings().setUseWideViewPort(true);
view.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
view.setScrollbarFadingEnabled(false);
return currentFragment;
}
}˚
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/black"
android:orientation="vertical"
tools:context="mathusummut.dabtest.TutorialFragment">
<TextView
android:id="@+id/tutorialTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="30dp"
android:text="Instructions"
android:textAlignment="center"
android:textSize="36sp" />
<WebView
android:id="@+id/tutorialGifView"
android:layout_width="330dp"
android:layout_height="300dp"
android:layout_gravity="center"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="30dp" />
<Button
android:id="@+id/nextButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="20dp"
android:background="@android:color/holo_red_dark"
android:text="Next"
android:textAlignment="center"
android:textAllCaps="false"
android:textSize="24sp" />
我从 GitHub 中提取代码。我认为它没问题，对你来说工作正常。
我给你做一个单独的分支推送 GitHub.
我正在尝试在我的应用程序开始时实施分步教程。我创建了 3 个用户可以滚动浏览的片段实例。它们使用 FragmentPagerAdapter 组合，设置并添加到 TabLayout，以便将片段视为选项卡。选项卡指示符被赋予了自定义样式，因此它们显示为点。
我遇到的问题是，在设计视图中一切看起来都很好，但是当在模拟器中部署应用程序时，约束布局没有得到遵守，片段中视图控件的定位和大小最终变为一个不稳定的配置。 activity 仅设置为纵向，因此显示方向不是问题。
这是片段在设计视图中的显示方式：
在 WebView 个实例中加载了 3 个单独的 GIF（出于这个问题的目的，它们是随机的）。
这是模拟器中实际出现的一切：
可以看到，WebView是整个片段的大小，TextView和Button是找不到的，即使WebView 已删除。
这是完整的代码和 Android Studio 项目 与问题相关：https://github.com/mathusummut/WhosebugQuestionCode1
这是最相关的代码：
TutorialActivity.java:
package mathusummut.dabtest;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class TutorialActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tutorial);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
Fragment currentPage = new TutorialFragment();
Bundle currentBundle = new Bundle();
currentBundle.putString("tutorialText", "1. Turn the volume up ↑");
currentBundle.putString("tutorialGif", "file:///android_asset/volume.gif");
currentPage.setArguments(currentBundle);
adapter.addFragment(currentPage, "");
currentPage = new TutorialFragment();
currentBundle = new Bundle();
currentBundle.putString("tutorialText", "2. Grab the phone in one hand...");
currentBundle.putString("tutorialGif", "file:///android_asset/step2.gif");
currentPage.setArguments(currentBundle);
adapter.addFragment(currentPage, "");
currentPage = new TutorialFragment();
currentBundle = new Bundle();
currentBundle.putString("tutorialText", "Dab...");
currentBundle.putString("tutorialGif", "file:///android_asset/step3.gif");
currentPage.setArguments(currentBundle);
adapter.addFragment(currentPage, "");
ViewPager viewPager = findViewById(R.id.viewpager);
viewPager.setOffscreenPageLimit(3);
viewPager.setAdapter(adapter);
((TabLayout) findViewById(R.id.tabs)).setupWithViewPager(viewPager);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId()== android.R.id.home) {
finish();
return true;
} else
return super.onOptionsItemSelected(item);
}
public class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> fragmentList = new ArrayList<>();
private final List<String> fragmentTitleList = new ArrayList<>();
public ViewPagerAdapter(FragmentManager manager) {
super(manager);
}
@Override
public Fragment getItem(int position) {
return fragmentList.get(position);
}
@Override
public int getCount() {
return fragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
fragmentList.add(fragment);
fragmentTitleList.add(title);
}
@Override
public CharSequence getPageTitle(int position) {
return fragmentTitleList.get(position);
}
}
}
fragment_tutorial.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/black"
tools:context="mathusummut.dabtest.TutorialFragment">
<WebView
android:id="@+id/tutorialGifView"
android:layout_width="330dp"
android:layout_height="346dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="100dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</WebView>
<TextView
android:id="@+id/tutorialTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="36dp"
android:text="Instructions"
android:textAlignment="center"
android:textSize="36sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.502"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/nextButton"
android:layout_width="124dp"
android:layout_height="wrap_content"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="456dp"
android:layout_x="69dp"
android:layout_y="386dp"
android:background="@android:color/holo_red_dark"
android:text="Next"
android:textAlignment="center"
android:textAllCaps="false"
android:textSize="24sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
activity_tutorial.xml:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/coordinatorLayout2"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:id="@+id/appBarLayout2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:layout_constraintBottom_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="@+id/viewpager"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintStart_toStartOf="@+id/appBarLayout2"
app:layout_constraintTop_toTopOf="@+id/appBarLayout2">
</android.support.v4.view.ViewPager>
<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:tabBackground="@drawable/tab_selector"
app:tabGravity="center"
app:tabMode="fixed"
app:tabIndicatorHeight="0dp"/>
</android.support.constraint.ConstraintLayout>
我试过使用 RelativeLayout 而不是 ConstraintLayout，但更改似乎对结果没有影响。请问我该怎么做才能解决这个问题？
这是您完成我所需更改的代码。
enter image description here
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View currentFragment = inflater.inflate(R.layout.fragment_tutorial, container, false);
WebView view = currentFragment.findViewById(R.id.tutorialGifView);
Bundle passedArguments = getArguments();
((TextView) currentFragment.findViewById(R.id.tutorialTextView)).setText(passedArguments.getString("tutorialText"));
view.loadDataWithBaseURL(null, TEMPLATE_HTML.replace("gif", passedArguments.getString("tutorialGif")), "text/html", "utf-8", null);
view.setBackgroundColor(Color.TRANSPARENT);
view.setInitialScale(1);
view.getSettings().setJavaScriptEnabled(true);
view.getSettings().setLoadWithOverviewMode(true);
view.getSettings().setUseWideViewPort(true);
view.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
view.setScrollbarFadingEnabled(false);
return currentFragment;
}
}˚
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/black"
android:orientation="vertical"
tools:context="mathusummut.dabtest.TutorialFragment">
<TextView
android:id="@+id/tutorialTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="30dp"
android:text="Instructions"
android:textAlignment="center"
android:textSize="36sp" />
<WebView
android:id="@+id/tutorialGifView"
android:layout_width="330dp"
android:layout_height="300dp"
android:layout_gravity="center"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="30dp" />
<Button
android:id="@+id/nextButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="20dp"
android:background="@android:color/holo_red_dark"
android:text="Next"
android:textAlignment="center"
android:textAllCaps="false"
android:textSize="24sp" />