我使用的材料设计选项卡如下:
以下是我的MainActivity.class:
public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener {
private TabLayout tabLayout;
private ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tabLayout = (TabLayout) findViewById(R.id.tabs);
viewPager = (ViewPager) findViewById(R.id.viewpager);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(this);
tabLayout.setupWithViewPager(viewPager);
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
System.out.println("onPageSelected Called");
}
@Override
public void onPageScrollStateChanged(int state) {
}
}
我的ViewPagerAdapter如下:
public class ViewPagerAdapter extends FragmentPagerAdapter {
private static int count = 2;
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new FragmentOne();
case 1:
return new FragmentTwo();
}
return null;
}
@Override
public int getCount() {
return count;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position)
{
case 0 :
return "Tab One";
case 1 :
return "Tab Two";
}
return null;
}
}
这是我的片段:
这是我的第一个片段名称为FragmentOne:
public class FragmentOne extends Fragment {
private EditText editText;
private Button btnSendData;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
System.out.println("IN FRAGMENT ONE");
View view = inflater.inflate(R.layout.fragment_one,container,false);
editText = (EditText) view.findViewById(R.id.et_name);
btnSendData = (Button) view.findViewById(R.id.btn_send);
btnSendData.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentTwo fragment = new FragmentTwo();
Bundle bundle = new Bundle();
bundle.putString("username",editText.getText().toString());
fragment.setArguments(bundle);
getFragmentManager.beginTransaction.replace(R.id.frag_second,fragment).commit();
}
});
return view;
}
}
这是另一个名为FragmentTwo的片段:
public class FragmentTwo extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
System.out.println("IN FRAGMENT TWO");
View view = inflater.inflate(R.layout.fragment_two,container,false);
Bundle bundle = getArguments();
if(bundle!= null)
{
String value = getArguments().getString("username");
}
return view;
}
@Override
public void onResume() {
super.onResume();
System.out.println("onResume gets called");
}
}
在第二个片段中,我正在获取数据,但是它与先前的视图一起添加了另一个视图。
看到图片:
所以我想在两种情况下将数据从FragmentOne传递给FragmentTwo:
1.我想在单击按钮和
2.当我滑动到FragmentTwo时,应该传递数据
另外,当我尝试滑动到FragmentTwo时,在FragmentTwo中没有调用任何东西吗?为什么会这样呢?
另外,当我单击第二个选项卡时,什么也不会被调用。
请帮助我,如何在单击按钮时将数据传递给FragmentTwo?
以下是布局文件:
这是fragment_one
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical">
<EditText
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:id="@+id/et_name"
android:hint="Username"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<Button
android:padding="16dp"
android:text="Send Data"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:id="@+id/btn_send"
android:layout_height="wrap_content"
android:layout_width="match_parent"/>
第二个片段fragment_second.xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/second_frag"
android:gravity="center">
<TextView
android:textSize="24sp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Fragment Two"
android:id="@+id/textView2" />
最佳答案
每个片段都与父活动相关联。因此您不能直接从一个片段与另一个片段进行通信。您将需要使用界面进行“家长活动”。
检查此文档:https://developer.android.com/training/basics/fragments/communicating.html
单击按钮后,将值传递到自定义界面中的方法,然后在第二个片段中访问这些方法。
当我尝试滑动到FragmentTwo时,在FragmentTwo中什么都没叫
为此,您需要实现片段生命周期-https://developer.android.com/reference/android/app/Fragment.html
更新
在您的代码中进行了一些修改后,只需查看以下内容即可。代码-
Manifex.xml
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity"
android:theme="@style/Theme.AppCompat.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
MainActivity.java
package com.app.onkar.tabdemo;
import android.support.v4.app.Fragment;
import android.support.design.widget.TabLayout;
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.os.Bundle;
import android.support.v7.widget.Toolbar;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener {
private Toolbar toolbar;
private TabLayout tabLayout;
private ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
viewPager = (ViewPager) findViewById(R.id.viewpager);
tabLayout = (TabLayout) findViewById(R.id.tabs);
ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
adapter.addFragment(new FragmentOne(), "ONE");
adapter.addFragment(new FragmentTwo(), "TWO");
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(this);
tabLayout.setupWithViewPager(viewPager);
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
System.out.println("onPageSelected Called");
}
@Override
public void onPageScrollStateChanged(int state) {
}
public static class ViewPagerAdapter extends FragmentPagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();
private static int count = 2;
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new FragmentOne();
case 1:
return new FragmentTwo();
}
return null;
}
@Override
public int getCount() {
return count;
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "Tab One";
case 1:
return "Tab Two";
}
return null;
}
}
}
FragmentOne.java
package com.app.onkar.tabdemo;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
public class FragmentOne extends Fragment {
private EditText editText;
private Button btnSendData;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
System.out.println("IN FRAGMENT ONE");
View view = inflater.inflate(R.layout.fragment_one,container,false);
editText = (EditText) view.findViewById(R.id.et_name);
btnSendData = (Button) view.findViewById(R.id.btn_send);
btnSendData.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentTwo fragment = new FragmentTwo();
Bundle bundle = new Bundle();
bundle.putString("username",editText.getText().toString());
fragment.setArguments(bundle);
getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.second_frag,fragment).commit();
}
});
return view;
}
}
FragmentTwo.java
package com.app.onkar.tabdemo;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class FragmentTwo extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
System.out.println("IN FRAGMENT TWO");
View view = inflater.inflate(R.layout.fragment_two,container,false);
TextView txt2 = (TextView) view.findViewById(R.id.textView2);
Bundle bundle = getArguments();
if(bundle!= null)
{
String value = getArguments().getString("username");
txt2.setText(value);
}
return view;
}
@Override
public void onResume() {
super.onResume();
System.out.println("onResume gets called");
}
}
布局文件没有变化。只需尝试上面的代码-它完全可以按照您的要求工作。希望对您有所帮助!
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