控件--spinner(列表选项框)

1. 关键点

1). Spinner的菜单显示方式

它有两种显示形式,一种是下拉菜单,一种是弹出框,菜单显示形式是spinnerMode属性决定的:

android:spinnerMode="dropdown"

android:spinnerMode="dialog"

 

下面是Theme.Light和Theme.Holo.Light下Spinner在不同模式下的效果对比图。 

 

 

2). 在Spinner的xml属性

其实上面已经提到了Spinner的两个属性:

1 entries: 直接在xml布局文件中绑定数据源(可以不设置,即可以在Activity中动态绑定)

2 spinnerMode: Spinner的显示形式

 

2. 代码

 activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example2.spinner.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
    <Spinner
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:entries="@array/language"
        android:id="@+id/spinner"></Spinner>
</android.support.constraint.ConstraintLayout>

 

 \res\values\arrays.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="language">
        <item >C语言</item>
        <item >JAVA</item>
        <item >C++</item>
        <item >PHP</item>
        <item >其他</item>
    </string-array>
</resources>

 

MainActivity.java
package com.example2.spinner;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Spinner spinner = (Spinner)findViewById(R.id.spinner);
        //设置监听
        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                String[] res = getResources().getStringArray(R.array.language);
                Toast.makeText(MainActivity.this,"点击为"+res[i],Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
    }
}

 

 

posted on 2017-11-22 10:57  maogefff  阅读(2505)  评论(0编辑  收藏  举报

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