安卓：下拉列表spinner的联动

结果展示：

即点击第一个下拉列表内容时，第二个下拉列表的内容那个会根据第一个下拉列表内容改变而改变

代码部分

xml：
activity_spinner_test.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
  >
    <TextView
        android:text="请选择学院："
        android:textSize="50dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Spinner
        android:id="@+id/spinnerDepartment"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

    </Spinner>
    <TextView
        android:text="请选择班级："
        android:textSize="50dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <Spinner
        android:id="@+id/spinnerClass"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

    </Spinner>
    <TextView
        android:id="@+id/txtResult"

        android:textSize="50dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    </LinearLayout>

item_select.xml 下拉列表初始风格

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:textSize="40dp"
    android:typeface="serif"
    android:gravity="center"
    android:textColor="#000000"
    android:layout_height="match_parent"
    android:background="@color/colorAccent"
    android:orientation="vertical">
</TextView>

item_drop.xml 列表下拉后的风格

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="5dp"
    android:background="@color/colorPrimary"
    android:gravity="center"
    android:orientation="vertical"
    android:textColor="#000000"
    android:textSize="40dp">
</TextView>

java部分
SpinnerTestActivity.java

package com.example.firstapplication.spinner;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

import com.example.firstapplication.R;


public class SpinnerTestActivity extends Activity {

    Spinner spinnerDepartment, spinnerClass;
    TextView txtResult;
    String[] department = {"计算机学院", "土木学院", "信电学院"};
    String[][] class1 = {{"计科151", "计科152", "计科153"}, {"土木151", "土木152", "土木153"}, {"信电151", "信电152", "信电153"}};

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_spinner_test);

        spinnerDepartment = (Spinner) findViewById(R.id.spinnerDepartment);
        spinnerClass = (Spinner) findViewById(R.id.spinnerClass);
        txtResult = (TextView) findViewById(R.id.txtResult);

        ArrayAdapter adapterDepartment = new ArrayAdapter(SpinnerTestActivity.this, R.layout.item_select, department);
        adapterDepartment.setDropDownViewResource(R.layout.item_drop);
        spinnerDepartment.setAdapter(adapterDepartment);
        spinnerDepartment.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                ArrayAdapter adapterClass = new ArrayAdapter(SpinnerTestActivity.this, R.layout.item_select, class1[position]);
                adapterClass.setDropDownViewResource(R.layout.item_drop);
                spinnerClass.setAdapter(adapterClass);
            }

            public void onNothingSelected(AdapterView<?> parent) {
            }
        });
        spinnerClass.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                txtResult.setText("你选择的是" + spinnerClass.getSelectedItem().toString());
            }

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

            }
        });


    }

}

java代码分析：

1、为下拉列表设置新的下拉项目数据

//String[] department = {"计算机学院", "土木学院", "信电学院"};
//SpinnerTestActivity  java项目本身
//R.layout.item_select   R.layout_item_drop上面讲过

ArrayAdapter adapterDepartment = new ArrayAdapter(SpinnerTestActivity.this, R.layout.item_select, department);
        adapterDepartment.setDropDownViewResource(R.layout.item_drop);
        spinnerDepartment.setAdapter(adapterDepartment);

2、两个下拉列表联动关键代码块

spinnerDepartment.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                ArrayAdapter adapterClass = new ArrayAdapter(SpinnerTestActivity.this, R.layout.item_select, class1[position]);
                adapterClass.setDropDownViewResource(R.layout.item_drop);
                spinnerClass.setAdapter(adapterClass);
            }

            public void onNothingSelected(AdapterView<?> parent) {
            }
        });

3、下拉列表项目的选定

   spinnerClass.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                txtResult.setText("你选择的是" + spinnerClass.getSelectedItem().toString());
            }

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

            }
        });