Question

我构建了一个具有活动和以下布局的应用程序：

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fitsSystemWindows="true"
android:orientation="vertical" >

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:orientation="vertical" >

<TextView
    android:id="@+id/textView"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:scrollbars="vertical"
    android:textSize="18sp" />

<com.jjoe64.graphview.GraphView
    android:id="@+id/graph"
    android:layout_width="match_parent"
    android:layout_height="175dip" />

<RelativeLayout
    android:layout_width="match_parent"
    android:fitsSystemWindows="true"
    android:layout_height="60dp" >

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/send"
        android:layout_marginRight="80dp"
        android:layout_marginBottom="0dp"
        android:hint="Comment anything important about the next measurement(s)"
        android:singleLine="false" />

    <Button
        android:id="@+id/send"
        style="@style/button_text"
        android:layout_alignParentBottom="true"
        android:layout_width="80dp"
        android:layout_height="60dp"
        android:layout_alignParentRight="true"
        android:layout_marginRight="6dp"
        android:layout_toLeftOf="@id/editText"
        android:background="@drawable/red_button"
        android:text="Send" />

</RelativeLayout>

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="185dip"
    tools:context="com.example.mapwithmarker.MapsMarkerActivity" />


</LinearLayout>
</ScrollView>

我想将布局分为3个不同的选项卡，一个选项卡具有textView和按钮，一个选项卡具有graphView和一个地图。我想我必须对ViewPager做些事情，但是我不理解android指南（https://developer.android.com/training/implementing-navigation/lateral）上的示例，因为它在Fragment对象的集合上滑动，而不是我想要的不同布局。

我应该怎么做？还有其他方法可以解决吗？

更新的问题：

我遵循BenjyTec的建议，因此在活动中添加了代码，并进行了以下3种xml布局：

fragment1.xml

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
    android:id="@+id/textView"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:scrollbars="vertical"
    android:textSize="18sp" />

<RelativeLayout
    android:layout_width="match_parent"
    android:fitsSystemWindows="true"
    android:layout_height="60dp" >

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/send"
        android:layout_marginRight="80dp"
        android:layout_marginBottom="0dp"
        android:hint="Comment anything important about the next measurement(s)"
        android:singleLine="false" />

    <Button
        android:id="@+id/send"
        style="@style/button_text"
        android:layout_alignParentBottom="true"
        android:layout_width="80dp"
        android:layout_height="60dp"
        android:layout_alignParentRight="true"
        android:layout_marginRight="6dp"
        android:layout_toLeftOf="@id/editText"
        android:background="@drawable/red_button"
        android:text="Send" />

</RelativeLayout>

</LinearLayout>

fragment2.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<com.jjoe64.graphview.GraphView
    android:id="@+id/graph"
    android:layout_width="match_parent"
    android:layout_height="175dip" />

</LinearLayout>

fragment3.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="185dip"
    tools:context="com.example.mapwithmarker.MapsMarkerActivity" />

</LinearLayout>

因此，主布局（second.xml）现在是：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fitsSystemWindows="true"
android:orientation="vertical">

<android.support.v4.view.ViewPager
    android:id="@+id/viewPager"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

</LinearLayout>

但是现在当我运行应用程序时，它崩溃并显示以下错误：

java.lang.RuntimeException：无法启动活动 ComponentInfo {com.redbear.chat/com.redbear.chat.Chat}： java.lang.NullPointerException：尝试调用虚拟方法'void com.google.android.gms.maps.SupportMapFragment.getMapAsync（com.google.android.gms.maps.OnMapReadyCallback）' 在空对象引用上在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2426）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2490）在android.app.ActivityThread.-wrap11（ActivityThread.java）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1354）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:148）在android.app.ActivityThread.main（ActivityThread.java:5443）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:728）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:618）原因：java.lang.NullPointerException：尝试调用虚拟方法'void com.google.android.gms.maps.SupportMapFragment.getMapAsync（com.google.android.gms.maps.OnMapReadyCallback）' 在空对象引用上在com.redbear.chat.Chat.onCreate（Chat.java:185）在android.app.Activity.performCreate（Activity.java:6245）在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1130）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2379）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2490）在android.app.ActivityThread.-wrap11（ActivityThread.java）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1354）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:148）在android.app.ActivityThread.main（ActivityThread.java:5443）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:728）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:618）

我的活动如下：

public class Chat extends FragmentActivity implements OnMapReadyCallback {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second);

    ViewPager viewPager = findViewById(R.id.viewPager);
    viewPager.setOffscreenPageLimit(2);  //number of ViewPager pages that will be kept in storage while swiping
    ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager());
    viewPager.setAdapter(viewPagerAdapter);

    SupportMapFragment mapFragment = (SupportMapFragment) this.getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);

    graph = (GraphView) findViewById(R.id.graph);
    tv = (TextView) findViewById(R.id.textView);
    tv.setMovementMethod(ScrollingMovementMethod.getInstance());
    et = (EditText) findViewById(R.id.editText);
    btn = (Button) findViewById(R.id.send);
}

public class ViewPagerAdapter extends FragmentPagerAdapter {

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position) {
            case 0:
                return new FragmentA();
            case 1:
                return new FragmentB();
            case 2:
                return new FragmentC();
        }
        return new FragmentA();
    }

    @Override
    public int getCount() {
        return 3;  //number of Fragments inside the ViewPager
    }

}

public static class FragmentA extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        ViewGroup rootView = (ViewGroup) inflater.inflate(
                R.layout.fragment1, container, false);

        return rootView;
    }
}

public static class FragmentB extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        ViewGroup rootView = (ViewGroup) inflater.inflate(
                R.layout.fragment2, container, false);

        return rootView;
    }
}

public static class FragmentC extends Fragment  {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        ViewGroup rootView = (ViewGroup) inflater.inflate(
                R.layout.fragment3, container, false);

        return rootView;
    }
}

private GoogleMap mMap;

@Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;

    // Add a marker in Sydney, Australia, and move the camera.
    LatLng patras = new LatLng(38.246639, 21.734573);
    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(patras, 14));
    updateLocationUI();
    UiSettings set = mMap.getUiSettings();
    set.setZoomControlsEnabled(true);
}

private void updateLocationUI() {
    if (mMap == null) {
        return;
    }
    try {
        mMap.setMyLocationEnabled(true);
        mMap.getUiSettings().setMyLocationButtonEnabled(true);
    } catch (SecurityException e)  {
        Log.e("Exception: %s", e.getMessage());
    }
}

}

Answer 1

您可以按照文档中的示例创建具有三种不同布局的三个片段，并将它们添加到ViewPager中。假设您有三个片段FragmentA，FragmentB和FragmentC，它们的布局分别是TextView和Button，布局a_fragment.xml，GraphView和{{1} }}包含地图。

现在在您的activity_main.xml布局中：

b_fragment.xml

像这样在MainActivity.java中设置ViewPager：

c_fragment.xml

最后像这样创建一个ViewPagerAdapter类：

<androidx.constraintlayout.widget.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:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
</androidx.constraintlayout.widget.ConstraintLayout>

现在将用于设置TextView，Button，GraphView，Map的代码移到相应的Fragments中。例如，ViewPager viewPager = findViewById(R.id.viewPager); viewPager.setOffscreenPageLimit(2); //number of ViewPager pages that will be kept in storage while swiping ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager()); viewPager.setAdapter(viewPagerAdapter);的{{1}}内部的代码如下：

public class ViewPagerAdapter extends FragmentPagerAdapter {

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position) {
            case 0:
                return new FragmentA();
            case 1:
                return new FragmentB();
            case 2:
                return new FragmentC();
        }
        return new FragmentA();
    }

    @Override
    public int getCount() {
        return 3;  //number of Fragments inside the ViewPager
    }

}

以同样的方式，将Map的所有代码移动到相应的Fragment中，在您的情况下为onCreateView。

如何在3种不同的滑动视图中拆分布局

1 个答案: