将数据从一个设计选项卡传递到另一选项卡 [英] Pass data from one design tab to another tab

问题描述

我正在使用以下材料设计选项卡:

I am using material design tabs as follows :

以下是我的MainActivity.class:

Following is my 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:

My ViewPagerAdapter is as follows :

    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:

This is my first fragment name is 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:

and here is another fragment with name FragmentTwo :

 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，但是它添加了与前一个视图的另一个视图. 看到图片:

In the second fragment i am getting data buts its adding another view with previous one. see the image :

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
时传递数据 2.当我滑动到FragmentTwo时，应该传递数据

so I want to pass data from FragmentOne to FragmentTwo in two scenario :
1. I want to pass the data when i click on button and
2. When I swipe to FragmentTwo data should be passed

当我尝试滑动到FragmentTwo时，在FragmentTwo中什么也没有被调用吗?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?

Also when I try to swipe to FragmentTwo nothing gets called in FragmentTwo ? why is it so ? Also when I click to second tab nothing gets called . Please help me how should i pass data to FragmentTwo on button click ?

以下是布局文件: 这是fragment_one

following are layout files: here is 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:

and second fragment , 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" />

推荐答案

每个片段都与父活动相关联.因此您无法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".

Each fragment is associated with the parent activity. so you can't directly communicate from one fragment to another fragment. You will need to go through Parent Activity using interface.

检查此文档: https://developer.android.com/training/basics/fragments/communicating.html

在按钮上单击，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.

On button click pass the value to methods in your custom interface and access those methods in second fragment.

当我尝试滑动到FragmentTwo时，在FragmentTwo中什么都没叫

when I try to swipe to FragmentTwo nothing gets called in FragmentTwo

为此，您需要实现片段生命周期- https://developer .android.com/reference/android/app/Fragment.html

For this you need to implement fragment life cycle - 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-

Done with some modification in you code, just look at the foll. code -

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");
    }

}

布局文件中没有更改.只需尝试上面的代码-它完全可以按照您想要的方式工作.希望对您有所帮助！

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