瘋狂 Android 講義, 4/e – 下拉式選單(Spinner & TextView & AdapterView)範例 P120~P121
瘋狂 Android 講義, 4/e – 下拉式選單(Spinner & TextView & AdapterView)範例 P120~P121
資料來源:
https://github.com/daichangya/book/tree/master/android
https://pan.baidu.com/s/1d_xYJI0UQ_1tQzSj_V_NIg 提取码:70ch
https://hjwang520.pixnet.net/blog/post/405000676-%5Bandroid-studio%5D%E4%B8%8B%E6%8B%89%E5%BC%8F%E9%81%B8%E5%96%AE%28spinner%29%E7%AD%86%E8%A8%98
XML Code
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!-- 定义了一个Spinner组件-->
<Spinner
android:id="@+id/spinner"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="TextView" />
</LinearLayout>
Java Code
package com.example.as_test01;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.AdapterView;
import android.view.View;
public class MainActivity extends AppCompatActivity {
private TextView textView;
// 定义一个数组
public String[] arr = new String[]{"孙悟空", "猪八戒", "唐僧"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.textView);
// 获取界面布局文件中的Spinner组件
Spinner spinner = findViewById(R.id.spinner);
String[] arr = new String[]{"孙悟空", "猪八戒", "唐僧"};
// 创建ArrayAdapter对象
ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_spinner_dropdown_item, arr);//android.R.layout.simple_list_item_multiple_choice
// 为Spinner设置Adapter
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(spnOnItemSelected);
textView.setText("選項:"+spinner.getSelectedItem().toString());
}
private AdapterView.OnItemSelectedListener spnOnItemSelected = new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> parent, View view,
int pos, long id) {
String sPos=String.valueOf(pos);
String sInfo=parent.getItemAtPosition(pos).toString();
//String sInfo=parent.getSelectedItem().toString();
textView.setText("選項"+sPos+":"+sInfo);
}
public void onNothingSelected(AdapterView<?> parent) {
//
}
};
}