Android ViewPager没有在xml中显示,也没有在emulator中工作?
我有一个应用程序,其中屏幕的一部分用于显示有关学生的信息,其余部分使用tablayout和viewpager。我的问题是tablayout显示在设计编辑器中,但是viewpager没有。尽管编写了代码,但没有显示任何内容。告诉我哪里出了问题 CAMarksFragment.javaAndroid ViewPager没有在xml中显示,也没有在emulator中工作?,android,android-fragments,layout,android-viewpager,android-tablayout,Android,Android Fragments,Layout,Android Viewpager,Android Tablayout,我有一个应用程序,其中屏幕的一部分用于显示有关学生的信息,其余部分使用tablayout和viewpager。我的问题是tablayout显示在设计编辑器中,但是viewpager没有。尽管编写了代码,但没有显示任何内容。告诉我哪里出了问题 CAMarksFragment.java package com.learn.app; import android.content.Context; import android.content.SharedPreferences; import and
package com.learn.app;
import android.content.Context;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
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.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class CAMarksFragment extends Fragment {
TabLayout tabLayout;
ViewPager viewPager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_camarks, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//you can set the title for your toolbar here for different fragments different titles
getActivity().setTitle("CA Marks");
viewPager=(ViewPager)getActivity().findViewById(R.id.viewPager);
viewPager.setAdapter(new CustomAdapter(getActivity().getSupportFragmentManager(),getActivity().getApplicationContext()));
tabLayout=(TabLayout)getActivity().findViewById(R.id.tabLayout);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
});
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
SharedPreferences pref = getActivity().getApplicationContext().getSharedPreferences("AppStatus", 0); // 0 - for private mode
SharedPreferences.Editor editor = pref.edit();
editor.putBoolean("Home", false);
editor.commit();
}
private class CustomAdapter extends FragmentPagerAdapter {
private String[] fragments={"Theory","Practical"};
public CustomAdapter(FragmentManager supportFragmentManager, Context applicationContext) {
super(supportFragmentManager);
}
@Override
public Fragment getItem(int position) {
switch (position){
case 0:
return new Theory();
case 1:
return new Practical();
default:
return null;
}
}
@Override
public int getCount() {
return fragments.length;
}
@Override
public CharSequence getPageTitle(int position) {
return fragments[position];
}
}
}
package com.learn.app;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Practical extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_layout1, container, false);
}
}
package com.learn.app;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Theory extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_layout, container, false);
}
}
fragments\u camarks.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context="com.learn.app.TestTimeTableFragment">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/tablebackgrounds"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:weightSum="100"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:id="@+id/ca_all"
android:background="@drawable/allbackgrounds"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
>
<ImageButton
android:id="@+id/user_profile_photo"
android:layout_width="120dp"
android:layout_height="120dp"
android:layout_marginTop="10dp"
android:layout_centerHorizontal="true"
android:background="@drawable/profile_circular_border_imageview"
android:padding="20dp"
android:scaleType="centerCrop"
android:src="@drawable/defaultpic" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:text="Hewitt"
android:textStyle="bold"
android:textColor="#ffffff"
android:id="@+id/camarks_name"
android:padding="10dp"
/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="14dp"
android:id="@+id/camarks_dept"
android:text="Master of Computer Application"
android:textColor="#ffffff"
android:padding="10dp"
/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="14dp"
android:id="@+id/camarks_rollno"
android:text="15mx13"
android:textColor="#ffffff"
android:padding="10dp"
/>
</LinearLayout>
</LinearLayout>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:textColor="#ffffff"
android:textStyle="bold"
android:background="#80000000"
android:id="@+id/ca_title"
android:text="CA Marks"
android:gravity="center"
android:padding="10dp"
/>
</LinearLayout>
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/tabLayout"
android:layout_below="@id/ca_all"
android:background="@color/colorPrimaryDark"
app:tabGravity="fill"
app:tabMode="fixed"
>
</android.support.design.widget.TabLayout>
<android.support.v4.view.ViewPager
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/viewPager"
android:layout_below="@id/tabLayout"
android:layout_centerHorizontal="true"
>
</android.support.v4.view.ViewPager>
</RelativeLayout>
</ScrollView>
</FrameLayout>
Theory.java
package com.learn.app;
import android.content.Context;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
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.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class CAMarksFragment extends Fragment {
TabLayout tabLayout;
ViewPager viewPager;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_camarks, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//you can set the title for your toolbar here for different fragments different titles
getActivity().setTitle("CA Marks");
viewPager=(ViewPager)getActivity().findViewById(R.id.viewPager);
viewPager.setAdapter(new CustomAdapter(getActivity().getSupportFragmentManager(),getActivity().getApplicationContext()));
tabLayout=(TabLayout)getActivity().findViewById(R.id.tabLayout);
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
viewPager.setCurrentItem(tab.getPosition());
}
});
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
SharedPreferences pref = getActivity().getApplicationContext().getSharedPreferences("AppStatus", 0); // 0 - for private mode
SharedPreferences.Editor editor = pref.edit();
editor.putBoolean("Home", false);
editor.commit();
}
private class CustomAdapter extends FragmentPagerAdapter {
private String[] fragments={"Theory","Practical"};
public CustomAdapter(FragmentManager supportFragmentManager, Context applicationContext) {
super(supportFragmentManager);
}
@Override
public Fragment getItem(int position) {
switch (position){
case 0:
return new Theory();
case 1:
return new Practical();
default:
return null;
}
}
@Override
public int getCount() {
return fragments.length;
}
@Override
public CharSequence getPageTitle(int position) {
return fragments[position];
}
}
}
package com.learn.app;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Practical extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_layout1, container, false);
}
}
package com.learn.app;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Theory extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_layout, container, false);
}
}
fragment_布局包含带有文本视图的linearlayout。
在emulator中,viewpager不显示,TableLayout保持不可触摸。我在这里出错了。请帮助我继续。提前谢谢
模拟器输出
代码中有很多错误 在xml中:为viewpager添加
android:layout\u height=“match\u parent”
<android.support.v4.view.ViewPager
android:id="@+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/tabLayout"
android:layout_centerHorizontal="true">
这可能是因为您使用的是来自androidx的视图 它有ViewPager和ViewPager2 在build.gradle(:app)文件中添加以下行:
谢谢你的回复。Tablayout有效,我可以在选项卡之间进行选择。现在我需要为每个选项卡显示一个布局文件。你能帮我吗?如何在选择选项卡时更改viewpager的布局。您已经在适配器中调用viewpager片段
getItem()
方法初始化适配器,如:new CustomAdapter(getActivity().getSupportFragmentManager(),getActivity())
我已经尝试了您的建议。但是OnTabSelectedListener似乎不起作用,所以我不会让屏幕被实际或理论片段所取代。每当选择一个选项卡时,我都需要在屏幕上加载特定的片段。现在我所拥有的只是一个空白屏幕,它不会随着选项卡的选择而改变(代码应该可以工作..您是否在viewpager片段中添加了任何视图?将日志放在InAbSelected中,以查看它是否调用。尝试添加一些背景色以查看其加载是否正确?