Android开发之Fragment与Activity的数据交互通过回调机制实现（源代码分享）

  上一篇文章简单介绍了Android的回调机制的使用，这一篇博文将重点介绍Fragment碎片与activity的数据交互，fragment在Android开发中起着至关重要的作用，通过官方Android api我们可以看到，fragment有着自己的生命周期并依赖于它绑定的activity的生命周期而存在，那样activity与fragment怎样进行数据交互呢，请看此篇博文。

MainActiivity的代码

package com.example.f08_fragment03;

import com.example.f08_fragment03.Fragment02.Callback;

import android.os.Bundle;
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {
	private FragmentManager manager;// 创建fragment管理
	private FragmentTransaction transaction;// 创建fragment的事物
	private EditText editText;
	private Button button;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		editText = (EditText) this.findViewById(R.id.editText2);
		button = (Button) this.findViewById(R.id.button1);
		manager = getFragmentManager();
		transaction = manager.beginTransaction();
		final Fragment02 fragment02 = new Fragment02();
		transaction.add(R.id.left, fragment02, "left");
		transaction.commit();
		// 不管要实现怎样的功能都必须调用以下三个方法
		// manager=getFragmentManager();
		//transaction=manager.beginTransaction();
		// transaction.commit();提交数据
		button.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				//通过callback机制得到fragment的数据
				fragment02.getString(new Callback() {

					@Override
					public void getString(String msg) {
						// TODO Auto-generated method stub
						editText.setText(msg);
					}
				});
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

Fragment02的代码

package com.example.f08_fragment03;

import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;

public class Fragment02 extends Fragment {
	private Button button;
	private EditText editText;

	@Override
	public void onAttach(Activity activity) {
		// TODO Auto-generated method stub
		super.onAttach(activity);
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
	}

	// 在该方法中更新UI
	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
			Bundle savedInstanceState) {
		// TODO Auto-generated method stub

		View view = inflater.inflate(R.layout.left, null);
		button = (Button) view.findViewById(R.id.button1);
		editText = (EditText) view.findViewById(R.id.editText1);
		button.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View arg0) {
				//通过getActivity方法得到activity的控件，以此可以得到数据
				EditText eText = (EditText) getActivity().findViewById(
						R.id.editText2);
				Log.i("info", "------->" + eText.getText().toString());
				editText.setText(eText.getText().toString());

			}
		});
		return view;
	}

	@Override
	public void onStart() {
		// TODO Auto-generated method stub
		super.onStart();
	}

	@Override
	public void onResume() {
		// TODO Auto-generated method stub
		super.onResume();
	}

	@Override
	public void onPause() {
		// TODO Auto-generated method stub
		super.onPause();
	}
    //实现数据传递
	public void getString(Callback callback) {
		String msg = editText.getText().toString();
		callback.getString(msg);
	}
    //创建接口
	public interface Callback {
		public void getString(String msg);
	}

}

main的xml

<RelativeLayout 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"

    tools:context=".MainActivity" >

    <LinearLayout
        android:id="@+id/left"
        android:layout_width="200dp"
        android:layout_height="match_parent"
        android:background="#cbcbcb"
        android:orientation="vertical" >
    </LinearLayout>

    <LinearLayout
        android:id="@+id/right"
         android:layout_width="200dp"
        android:layout_height="match_parent"
        android:orientation="vertical" 
        >
        
        
    </LinearLayout>

    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_marginTop="14dp"
        android:layout_toRightOf="@+id/left"
        android:ems="10"
        android:inputType="textPassword" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editText2"
        android:layout_toRightOf="@+id/left"
        android:text="得到Fragment的数据" />

</RelativeLayout>

fragment的xml

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

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="text"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="得到Activity的数据" />

</LinearLayout>

      这样就大功告成了，点击fragment的button就可以在其editText控件显示activity的editText控件的文字，点击activity的button就可以得到fragment的编辑控件的数据！