Android课程---关于下拉列表与状态栏提示的学习

activity_ui7.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.hanqi.test5.UIActivity7"
    android:orientation="vertical">
 
    <AutoCompleteTextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="自动完成的文本编辑框"
        android:id="@+id/actv_1"/>
 
    <Spinner
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/sp_1"></Spinner>
    <!--Spinner:下拉列表-->
 
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="显示状态栏提示"
        android:onClick="notification_OnClick"/>
 
</LinearLayout>

UIActivity7.java

package com.hanqi.test5;
 
import android.app.Notification;
import android.app.NotificationManager;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Spinner;
import android.widget.Toast;
 
public class UIActivity7 extends AppCompatActivity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ui7);
 
        AutoCompleteTextView actv_1 = (AutoCompleteTextView)findViewById(R.id.actv_1);
 
        //设置自动完成的数据源
        String[] strings = {"China","Child","Chile","Chinese","Add","All","Class"};
 
        ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,R.layout.layout_array,strings);
 
        actv_1.setAdapter(arrayAdapter);
 
        //下拉列表
        Spinner sp_1 = (Spinner)findViewById(R.id.sp_1);
        sp_1.setAdapter(arrayAdapter);
        sp_1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(UIActivity7.this, "position = " + position, Toast.LENGTH_SHORT).show();
            }
 
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                Toast.makeText(UIActivity7.this, "什么也没选", Toast.LENGTH_SHORT).show();
 
            }
        });
 
    }
    public void notification_OnClick(View v)
    {
        //获取状态栏消息管理器  产生状态栏提示
        NotificationManager nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
 
        //构造状态栏消息
        Notification nt = new Notification.Builder(this)
                .setContentTitle("这是一条通知")
                .setContentText("这是通知内容:明天要休息了")
                .setTicker("显示在状态栏的新通知")
                .setSmallIcon(R.drawable.vipflower)
                .setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_SOUND)
 
                .build();
 
        //交给管理器发通知
        nm.notify(0,nt);
 
    }
}

显示效果如下：