MainActivity如下:

package cn.testcallback;

import android.os.Bundle;

import android.app.Activity;

/**

 * Demo描述:

 * Android中回调接口的使用

 */

public class MainActivity extends Activity {

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.main);

		testCallBack();

	}

	private void testCallBack(){

		AskQuestion askQuestion=new AskQuestion();

		String questionString="Do you love me ?";

		System.out.println("The question is : "+questionString);

		askQuestion.askQuestion(questionString);

	}

}

CallBackInterface如下:

package cn.testcallback;

/**

 * 定义一个接口

 * 接口中有一方法

 */

public interface CallBackInterface {

	public void answerQuestion(String result);

}

AskQuestion如下:

package cn.testcallback;

public class AskQuestion implements CallBackInterface{

    public void askQuestion(final String questionString){

    	new Thread(){

    		public void run() {

    			AnswerQuestion answerQuestion=new AnswerQuestion();

    			answerQuestion.receiveQuestion(AskQuestion.this, questionString);

    		};

    	}.start();

    }

	@Override

	public void answerQuestion(String result) {

        System.out.println("The answter is : "+result);

	}

}

AnswerQuestion如下:

package cn.testcallback;

public class AnswerQuestion {

   public void receiveQuestion(CallBackInterface callBackInterface,String questionString){

		try {

            Thread.sleep(3000);

		} catch (Exception e) {

		}

		String result="YES!!!";

		callBackInterface.answerQuestion(result);

   }

}

main.xml如下:

<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"

   >

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="回调的使用"

        android:layout_centerInParent="true"

    />

</RelativeLayout>