1. 新增公用單元檔案com..java

package com.example.myapplication;

import android.app.AlertDialog;
import android.content.Context;
import android.widget.Toast;

public class com {

	//提示資訊
	public static void ShowMsg(String msg,Context context) {
        AlertDialog.Builder dlg = new AlertDialog.Builder(context);
        dlg.setTitle("提示");
        dlg.setMessage(msg);
        dlg.setPositiveButton("確定",null);
        dlg.show();
	}
	
	//閃現提示
	public static void DisplayToast(String msg,Context context) {
		Toast.makeText(context, msg, Toast.LENGTH_SHORT).show();
	}
}
 

3.MainActivity.java新建方法名btn_clicked並呼叫com.java的方法

    public void btn_clicked(View view){
        com.ShowMsg("這是提示框",MainActivity.this);
        com.DisplayToast("這是閃現提示",getBaseContext());
    }