我正在处理 fragment

我正在尝试实现的用例::

• 我正在使用动态 fragment
• 我在一个 Activity 中使用了三个 fragment
• 我的目标是在所有三个 fragment 之间进行通信
• 我正在使用 fragment 的支持包

每个 fragment 都有一个小部件

• my_fragment1 有 edittext
• my_fragment2 有 按钮
• my_fragment3 有 TextView

点击 button 来自 edittext 的文本必须显示在 textview

到目前为止，我已经尝试过构建以下大部分场景

Top_Fragment.java

public class Top_Fragment extends Fragment{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub

        View view=inflater.inflate(R.layout.my_fragment1, container, false);

        return view;
    }
}

Middle_Fragment.java

package com.example.deleteme;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;

public class Middle_Fragment extends Fragment{

    View view;
    Button btn;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub

        view=inflater.inflate(R.layout.my_fragment2, container, false);
        btn=(Button) view.findViewById(R.id.button1);
        btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub



            }
        });
        return view;
    }
}

Bottom_Fragment.java

public class Bottom_Fragment extends Fragment{

    View view;
    TextView display_text;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        view=inflater.inflate(R.layout.my_fragment3, container,false);
        display_text=(TextView) view.findViewById(R.id.editText1);
        return view;
    }

    public void setName(String Name){
        display_text.setText("Result::" + Name);
    }



}

MainActivity.java

public class MainActivity extends FragmentActivity {

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

        Top_Fragment frg=new Top_Fragment();//create the fragment instance for the top fragment
        Middle_Fragment frg1=new Middle_Fragment();//create the fragment instance for the middle fragment
        Bottom_Fragment frg2=new Bottom_Fragment();//create the fragment instance for the bottom fragment

        FragmentManager manager=getSupportFragmentManager();//create an instance of fragment manager

        FragmentTransaction transaction=manager.beginTransaction();//create an instance of Fragment-transaction

        transaction.add(R.id.My_Container_1_ID, frg, "Frag_Top_tag");
        transaction.add(R.id.My_Container_2_ID, frg1, "Frag_Middle_tag");
        transaction.add(R.id.My_Container_3_ID, frg2, "Frag_Bottom_tag");


        transaction.commit();

    }


}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    tools:context=".MainActivity" 
    android:background="@color/black">

    <FrameLayout
        android:id="@+id/My_Container_1_ID"
        android:layout_width="fill_parent"
        android:layout_height="150dp" 
        android:background="@color/yellow">
    </FrameLayout>

    <FrameLayout
        android:id="@+id/My_Container_2_ID"
        android:layout_width="fill_parent"
        android:layout_height="150dp"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/My_Container_1_ID"
        android:background="@color/Orange" >
    </FrameLayout>

    <FrameLayout
        android:id="@+id/My_Container_3_ID"
        android:layout_width="fill_parent"
        android:layout_height="150dp"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/My_Container_2_ID"
        android:background="@color/purple" >
    </FrameLayout>

</RelativeLayout>

my_fragment1.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/green" >

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:ems="10"
        android:textColor="#000000"
        android:singleLine="true" >

        <requestFocus />
    </EditText>

</RelativeLayout>

my_fragment2.xml

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

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:background="@color/black"
        android:text="Button"
        android:textColor="#FFFFFF" />

</RelativeLayout>

my_fragment3.xml

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

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="TextView"
        android:textColor="#000000"
        android:textSize="30dp" />

</RelativeLayout>

我的输出如下所示::

我在实现方面遇到的问题::

• 我无法将从 edit text 获得的值设置为 textview 点击按钮

有什么想法吗？

最佳答案

所有 Fragment 到 Fragment 的通信都是通过关联的 Activity 完成的。两个 Fragment 永远不应该直接通信。

http://developer.android.com/training/basics/fragments/communicating.html

test.java//在你的情况下是它的 MainActivity

public class test extends FragmentActivity implements textEntered {

    String value;
    boolean check = false;
    BottomFragment frg2;
    FragmentTransaction transaction;

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

        Top_Fragment frg = new Top_Fragment();
        frg2 = new BottomFragment();

        FragmentManager manager = getSupportFragmentManager();
        transaction = manager.beginTransaction();
        transaction.add(R.id.My_Container_1_ID, frg, "Frag_Top_tag");
        transaction.add(R.id.My_Container_3_ID, frg2, "Frag_Bottom_tag");
        transaction.commit();
    }

    @Override
    public void setValue(String editextvalue) {
        value = editextvalue;
        if (frg2 != null) {
            frg2.setName(value);
        } else {
            Toast.makeText(getApplicationContext(), "fragment 2  is null", 1000).show();
        }
    }

}    

Top_Fragment.java

public class Top_Fragment extends Fragment {
    textEntered mCallback;
    Button b;
    EditText ed;

    public interface textEntered {
        public void setValue(String editextvalue);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
        // TODO Auto-generated method stub

        View view = inflater.inflate(R.layout.my_fragment1, container, false);
        ed = (EditText) view.findViewById(R.id.editText1);


        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onActivityCreated(savedInstanceState);
        b = (Button) getView().findViewById(R.id.button1);
        b.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String s = ed.getText().toString();
                mCallback.setValue(s);
            }

        });
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);

        // This makes sure that the container activity has implemented
        // the callback interface. If not, it throws an exception
        try {
            mCallback = (textEntered) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString() +
                " must implement textEntered");
        }
    }
}

my_fragment1.xml

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

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:ems="10"
        android:textColor="#000000"
        android:singleLine="true" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editText1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:text="Button" />

</RelativeLayout>

改成

 display_text=(TextView) view.findViewById(R.id.textView1);
 // id is textView 1 not editText1

在底部 fragment 中

抓拍

关于java - 在单个 Activity 中动态实现多个 fragment ，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/19722979/