使用多个微调器（android）

Question

so im really new to the world of android and im trying to code some very basic stuff.I would like to know whats the code to display and make multiple spinner works; so far I did this but I get an error "The type new AdapterView.OnItemSelectedListener(){} must implement the inherited abstract method AdapterView.OnItemSelectedListener.onNothingSelected(AdapterView)".Heres XML:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.example.spinnertest.MainActivity" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

</TextView>

<EditText
    android:id="@+id/editText1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/spinner3"
    android:layout_below="@+id/textView1"
    android:layout_marginLeft="68dp"
    android:ems="10"
    android:inputType="number" >

    <requestFocus />
</EditText>

<Spinner
    android:id="@+id/spinner2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/spinner3"
    android:layout_toRightOf="@+id/editText1"
    android:entries="@array/Type" />

<Spinner
    android:id="@+id/spinner1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/editText1"
    android:layout_alignParentLeft="true"
    android:entries="@array/Produits" />

<EditText
    android:id="@+id/editText2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@+id/textView1"
    android:ems="10"
    android:inputType="number" />

<EditText
    android:id="@+id/editText3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/editText1"
    android:layout_toLeftOf="@+id/editText2"
    android:ems="10"
    android:inputType="number" />

<EditText
    android:id="@+id/editText4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@+id/spinner2"
    android:ems="10"
    android:inputType="number" />

<Spinner
    android:id="@+id/spinner3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignRight="@+id/editText4"
    android:layout_below="@+id/spinner4" />

<Spinner
    android:id="@+id/spinner4"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/editText3"
    android:layout_toRightOf="@+id/editText1" />

<TextView
    android:id="@+id/textView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/editText3"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="23dp"
    android:text="TextView" />

<Spinner
    android:id="@+id/spinner5"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignTop="@+id/editText4"
    android:layout_toRightOf="@+id/button1" />

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/textView2"
    android:layout_marginLeft="93dp"
    android:layout_toRightOf="@+id/textView2"
    android:text="Button" />

</RelativeLayout>

and heres java code:

package com.example.spinnerTest;


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



public class MainActivity extends Activity {


Spinner s1,s2;
TextView txt;

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

s1 = (Spinner) findViewById(R.id.spinner1);
    txt = (TextView) findViewById(R.id.textView2);

    s1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
            String val = s1.getSelectedItem().toString();
            txt.setText(val);
        }

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

        }
    });

    s2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
            String val = s2.getSelectedItem().toString();
            txt.setText(val);
        }

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

        }
    });}}

So im just trying to make 2 spinner(and more after) to display and works at the same time.I also gets these errors when launching it on emulated device:

10-12 15:39:19.388: E/Trace(831): error opening trace file: No such file or directory (2)
10-12 15:39:20.269: D/AndroidRuntime(831): Shutting down VM
10-12 15:39:20.269: W/dalvikvm(831): threadid=1: thread exiting with uncaught exception         (group=0x40a13300)
10-12 15:39:20.279: E/AndroidRuntime(831): FATAL EXCEPTION: main
10-12 15:39:20.279: E/AndroidRuntime(831): java.lang.RuntimeException: Unable to start activity     ComponentInfo{com.example.spinnertest/com.example.spinnertest.MainActivity}:     java.lang.NullPointerException
10-12 15:39:20.279: E/AndroidRuntime(831):  at     android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.ActivityThread.access$600(ActivityThread.java:130)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.os.Looper.loop(Looper.java:137)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.ActivityThread.main(ActivityThread.java:4745)
10-12 15:39:20.279: E/AndroidRuntime(831):  at java.lang.reflect.Method.invokeNative(Native Method)
10-12 15:39:20.279: E/AndroidRuntime(831):  at java.lang.reflect.Method.invoke(Method.java:511)
10-12 15:39:20.279: E/AndroidRuntime(831):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-12 15:39:20.279: E/AndroidRuntime(831):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-12 15:39:20.279: E/AndroidRuntime(831):  at dalvik.system.NativeStart.main(Native Method)
10-12 15:39:20.279: E/AndroidRuntime(831): Caused by: java.lang.NullPointerException
10-12 15:39:20.279: E/AndroidRuntime(831):  at com.example.spinnertest.MainActivity.onCreate(MainActivity.java:40)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.Activity.performCreate(Activity.java:5008)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
10-12 15:39:20.279: E/AndroidRuntime(831):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
10-12 15:39:20.279: E/AndroidRuntime(831):  ... 11 more

Thanks!

Answer 1

You are missing the @Override annotations above the methods of the anonymous classes.

Also you need you must implement both methods for interface to work.

s1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
        String val = s1.getSelectedItem().toString();
        txt.setText(val);
    }

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

    }
});

s2.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
        String val = s2.getSelectedItem().toString();
        txt.setText(val);
    }

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

    }
});