Question

我正在尝试在我的应用开始时实施分步教程。我创建了3个用户可以滚动的片段实例。它们使用FragmentPagerAdapter进行组合，设置并添加到TabLayout，以便将片段视为制表符。选项卡指示器具有自定义样式，以便它们显示为点。

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，不会遵守约束布局，并且片段内视图控件的定位和大小调整最终会变得难以理解组态。活动仅设置为纵向，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（出于此问题的目的，它们是随机的）。

这就是模拟器中实际出现的一切：

正如您所看到的，WebView是整个片段的大小，TextView和Button无处可寻，即使{{1>已删除。

以下是与问题相关的整个代码和 Android Studio项目：https://github.com/mathusummut/StackOverflowQuestionCode1

以下是最相关的代码：

TutorialActivity.java：

WebView

fragment_tutorial.xml：

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);
        }
    }
}

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/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>

我尝试使用<?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>而不是RelativeLayout，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？

Answer 1

这是你完成了我需要的更改的代码。

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中提取你的代码。我认为它没问题并且对你很好。我为你做了一个单独的分支推送GitHub。

在活动中TabLayout内的片段的约束问题

1 个答案: