Why spinner activity is not running? Error:Unfortunately spinnerapp has been stopped

Why spinner activity is not running? Error:Unfortunately spinnerapp has been stopped

我的问题是,当我 运行 微调器代码时,它显示错误

"Unfortunately spinnerApp has been stopped"

下面是我的 XML 文件:

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


<Spinner
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:layout_alignParentStart="true"
    android:layout_alignParentTop="true"
    android:layout_marginTop="113dp"
    android:layout_alignParentLeft="true" />
</RelativeLayout>

下面是我的strings.xml:

<resources>
    <string name="app_name">SpinnerApp</string>
    <string-array name="myarray">
        <item value="Oswald">Oswald</item>
        <item value="Noddy">Noddy</item>
        <item value="Shinchan">Shinchan</item>
        <item value="Doraemon">Doraemon</item>
        <item value="Detective Conan">Detective Conan</item>
        <item value="Power puff girls">Power puff girls</item>
        <item value="Ojarumaru">Ojarumaru</item>
        <item value="Bob the builder">Bob the builder</item>
        <item value="Asari chan">Asari chan</item>
        <item value="Maruko chan">Maruko chan</item>
        <item value="Mighty masked cat niyander">Mighty masked cat niyander</item>

    </string-array>
</resources>

下面是我的 .java 文件:

package com.example.mypc.spinnerapp;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.*;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    Spinner sp;
    ArrayAdapter adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sp=(Spinner)findViewById(R.id.spinner);
        List<String> list=new ArrayList<String>();
        list.add("Hello");
        list.add("World");
        list.add("How");
        list.add("are");
        list.add("you");

        String []arr=getResources().getStringArray(R.array.myarray);
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,list);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        sp.setAdapter(adapter);
        sp.setOnItemClickListener(new AdapterView.OnItemClickListener() {
           @Override
           public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
               sp.setSelection(position);
           }
       });
    }
}

我的代码有什么问题?

根本原因:

Caused by: java.lang.RuntimeException: setOnItemClickListener cannot be used with a spinner.

解决方法:改用setOnItemSelectedListener

更改您的代码:

来自

sp.setOnItemClickListener(new AdapterView.OnItemClickListener() {
       @Override
       public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
           sp.setSelection(position);
       }
});

sp.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    }

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

    }
});