Handler嵌套--可以

package com.example.handlernestdemo;

import android.support.v7.app.ActionBarActivity;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;

import android.view.View;
import android.widget.Button;
import android.widget.Toast;

@SuppressLint("HandlerLeak")
public class MainActivity extends ActionBarActivity {
    private Handler mHandler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case 1:
                Message msg1 = obtainMessage();
                msg1.what = 1;
                // myHandler再次发送
                myHandler.sendMessage(msg1);
                break;

            default:
                break;
            }
            super.handleMessage(msg);
        }
    };
    private Handler myHandler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
            case 1:
                Toast.makeText(getApplicationContext(), "嵌套实现了。", Toast.LENGTH_LONG).show();
                break;

            default:
                break;
            }

            super.handleMessage(msg);
        }

    };

    private Button button1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button1 = (Button) findViewById(R.id.button1);
        button1.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Message message = new Message();
                message.what = 1;
                // mHandler按钮发送一个message
                mHandler.sendMessage(message);

            }
        });
    }

}