我想根据上一个爬行器的选定项在爬行器中添加项?如何添加？

Question

我在我的application.one(旋转器1)中有2个旋转器用于选择资质，另一个( spinner2 )是根据在旋转器1中选择的资质来显示课程。如何在旋转器1中选择的项目的基础上在spinner2中添加项目。

Answer 1

尝试此代码：

Java类

package com.example.spinnerexam;
    import java.util.ArrayList;
    import java.util.List;

    import android.annotation.TargetApi;
    import android.app.Activity;
    import android.os.Build;
    import android.os.Bundle;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.AdapterView.OnItemSelectedListener;
    import android.widget.ArrayAdapter;
    import android.widget.Spinner;

    @TargetApi(Build.VERSION_CODES.HONEYCOMB)
    public class SpinnerExample extends Activity  implements OnItemSelectedListener{

        private Spinner qualificationSpinner, coursesSpinner;
        ArrayAdapter<String> courseAdapter;

        List<ArrayList<String>>  allCoursesList;
        CustomOnItemSelectedListener pCustomOnItemSelectedListener;
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            qualificationSpinner = (Spinner) findViewById(R.id.spinner1);
            coursesSpinner = (Spinner) findViewById(R.id.spinner2);

            List<String> qualificationList = new ArrayList<String>();  
            qualificationList.add("B.tech");
            qualificationList.add("M.tech");
            qualificationList.add("MCA");

            ArrayList<String> cources_Btech = new ArrayList<String>();  
            cources_Btech.add("Btechcourse1");
            cources_Btech.add("Btechcourse2");
            cources_Btech.add("Btechcourse3");

            ArrayList<String> cources_Mtech = new ArrayList<String>();  
            cources_Mtech.add("Mtechcourse1");
            cources_Mtech.add("Mtechcourse2");
            cources_Mtech.add("Mtechcourse3");

            ArrayList<String> cources_MCA = new ArrayList<String>();  
            cources_MCA.add("MCAcourse1");
            cources_MCA.add("MCAcourse2");
            cources_MCA.add("MCAcourse3");

            allCoursesList = new ArrayList<ArrayList<String>>(); 
            allCoursesList.add(cources_Btech);
            allCoursesList.add(cources_Mtech);
            allCoursesList.add(cources_MCA);




            ArrayAdapter<String> qualificationAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, qualificationList);

            qualificationAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

            qualificationSpinner.setAdapter(qualificationAdapter);


            courseAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item);  
            courseAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            coursesSpinner.setAdapter(courseAdapter);

            addListenerOnSpinnerItemSelection();


        }

        // Add spinner data

        public void addListenerOnSpinnerItemSelection(){

            qualificationSpinner.setOnItemSelectedListener(this);
            coursesSpinner.setOnItemSelectedListener(this);
        }


        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int pos,  long id) {
            courseAdapter.clear();
            courseAdapter.addAll(allCoursesList.get(pos));
            courseAdapter.notifyDataSetChanged();
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {

        }

    }

XML布局

 <?xml version="1.0" encoding="utf-8"?>
        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="vertical" >

            <Spinner
                android:id="@+id/spinner1"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:prompt="@string/spinner_prompt" />

             <Spinner
                android:id="@+id/spinner2"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:prompt="@string/spinner_prompt" />

        </LinearLayout>