嗨，大家好，我正在开发一个应用程序。我想让使用者从微调器中选择他/她的生日。我将根据spinner3更改天数。如果用户选择一个有30天的月份，则我的应用程序需要将微调框4设置为仅包含不超过30的数字。当用户选择某个微调框3时，我需要此设置。但是，当我打开应用程序时，它崩溃了。如果我注释掉这一行，它不会崩溃：
spinner3.setOnItemSelectedListener（this）; （解决了）
新问题：仅运行onItemSelected（AdapterView parent，View view，int pos，long id）
希望您能找到问题所在。谢谢
SignUp2.java：
package com.geniboys.sosyaaal;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import android.app.ActionBar;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
public class SignUp2 extends Activity implements
AdapterView.OnItemSelectedListener {
Spinner spinner4 = (Spinner) findViewById(R.id.spinner4);
Spinner spinner2 = (Spinner) findViewById(R.id.spinner2);
Spinner spinner3 = (Spinner) findViewById(R.id.spinner3);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_up2);
ActionBar actionBar = getActionBar();
actionBar.hide();
List<String> list = new ArrayList<String>();
Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
for(int i = 1972; i <= year+4; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner2.setAdapter(dataAdapter);
spinner3.setOnItemSelectedListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.sign_up2, menu);
return true;
}
public void onItemSelected(AdapterView<?> parent, View view, int pos, long id)
{
// An item was selected. You can retrieve the selected item using
String ay = (String) parent.getItemAtPosition(pos);
List<String> list = new ArrayList<String>();
if( ay == "Ocak" || ay == "Mart" || ay == "Mayıs" || ay == "Temmuz" || ay == "Ekim" || ay == "Aralık")
{
for(int i = 1; i<=31; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
if( ay == "Şubat" )
{
for(int i = 1; i<=28; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
else
{
for(int i = 1; i<=30; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(SignUp2.this, android.R.layout.simple_spinner_item, list);
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner4.setAdapter(dataAdapter);
}
@Override
public void onNothingSelected(AdapterView<?> arg0)
{
}
public void geri( View view )
{
super.onBackPressed();
}
public void ileri( View view)
{
}
}
activity_sign_up2.xml：
<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/registerbackground"
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=".SignUpActivity" >
<Button
android:id="@+id/button2"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/textView4"
android:layout_alignRight="@+id/editText1"
android:onClick="ileri"
android:text="@string/layoutIleri"
android:textColor="#ffffff" />
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="28dp"
android:layout_marginTop="70dp"
android:text="@string/loginTanim"
android:textColor="#ffffff"
android:textSize="20sp" />
<TextView
android:id="@+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="30dp"
android:text="@string/loginKayit"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textColor="#ffffff" />
<Button
android:id="@+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/textView4"
android:layout_alignLeft="@+id/textView1"
android:onClick="geri"
android:text="@string/layoutGeri"
android:textColor="#ffffff" />
<EditText
android:id="@+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/textView1"
android:layout_toRightOf="@+id/textView1"
android:ems="10"
android:hint="@string/loginAdhint"
android:textColor="#ffffff" />
<Spinner
android:id="@+id/spinner2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/editText1"
android:layout_alignTop="@+id/textView3"
android:layout_toRightOf="@+id/textView3"
android:textColor="#ffffff" />
<EditText
android:id="@+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="@+id/textView2"
android:layout_alignLeft="@+id/textView1"
android:layout_alignRight="@+id/textView2"
android:textColor="#ffffff"
android:ems="10" >
</EditText>
<EditText
android:id="@+id/editText3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_toRightOf="@+id/editText2"
android:textColor="#ffffff"
android:ems="10" />
<requestFocus />
<Spinner
android:id="@+id/spinner1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/spinner2"
android:layout_alignTop="@+id/textView2"
android:entries="@array/loginSehirler"
android:prompt="@string/loginMemlekethint"
android:textColor="#ffffff" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/TextView01"
android:layout_below="@+id/editText3"
android:layout_marginTop="24dp"
android:text="@string/loginMemleket"
android:textColor="#ffffff"
android:textSize="20sp" />
<TextView
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/spinner2"
android:layout_toLeftOf="@+id/spinner2"
android:text="@string/loginDogumTarihi"
android:textColor="#ffffff"
android:textSize="20sp" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/textView4"
android:layout_below="@+id/spinner1"
android:text="@string/loginMezuniyet"
android:textColor="#ffffff"
android:textSize="20sp" />
<Spinner
android:id="@+id/spinner3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/TextView01"
android:layout_marginTop="11dp"
android:layout_toLeftOf="@+id/editText3"
android:entries="@array/loginAylar"
android:prompt="@string/loginAylarhint" />
<Spinner
android:id="@+id/spinner5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/spinner4"
android:layout_alignLeft="@+id/spinner2"
android:layout_alignParentRight="true" />
<Spinner
android:id="@+id/spinner4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/spinner3"
android:layout_alignTop="@+id/spinner3"
android:layout_toLeftOf="@+id/spinner5"
android:layout_toRightOf="@+id/spinner3" />
</RelativeLayout>
编辑：添加LogCat：
01-23 18:31:49.730: W/InputEventReceiver(28607): Attempted to finish an input event but the input event receiver has already been disposed.
01-23 18:31:49.730: W/InputEventReceiver(28607): Attempted to finish an input event but the input event receiver has already been disposed.
01-23 18:31:53.150: W/InputEventReceiver(28607): Attempted to finish an input event but the input event receiver has already been disposed.
01-23 18:31:57.930: W/InputEventReceiver(28607): Attempted to finish an input event but the input event receiver has already been disposed.
01-23 18:32:00.270: W/InputEventReceiver(28607): Attempted to finish an input event but the input event receiver has already been disposed.
01-23 18:32:10.310: W/InputEventReceiver(28607): Attempted to finish an input event but the input event receiver has already been disposed.
编辑：添加答案
我不能回答我的问题。请将此屁股添加为答案：
在此处更改if语句：
if( ay == "Ocak" || ay == "Mart" || ay == "Mayıs" || ay == "Temmuz" || ay == "Ekim" || ay == "Aralık")
{
for(int i = 1; i<=31; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
if( ay == "Şubat" )
{
for(int i = 1; i<=28; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
else
{
for(int i = 1; i<=30; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
至
if( ay.equals("Ocak") || ay.equals("Mart") || ay.equals("Mayıs") || ay.equals("Temmuz") || ay.equals("Ekim") || ay.equals("Aralık"))
{
for(int i = 1; i<=31; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
else if( ay.equals("Şubat") )
{
for(int i = 1; i<=28; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
else
{
for(int i = 1; i<=30; ++i )
{
String foo = Integer.toString(i);
list.add(foo);
}
}
并在方法中声明微调框可以解决该问题。谢谢大家的帮助。
最佳答案
您不能在方法外部初始化Views。这将尝试在设置layout之前初始化它们，这意味着它们将成为null，因为它们存在于您的layout中。更改为
public class SignUp2 extends Activity implements
AdapterView.OnItemSelectedListener {
//declare here
Spinner spinner4;
Spinner spinner2;
Spinner spinner3;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_up2);
//initialize here after you have called setContentView()
spinner4 = (Spinner) findViewById(R.id.spinner4);
spinner2 = (Spinner) findViewById(R.id.spinner2);
spinner3 = (Spinner) findViewById(R.id.spinner3);
脱离主题在某些时候，您将需要学习为
View和其他变量指定更具体，有意义的名称。您有3个Spinners，并且知道哪个实际上会做些什么，例如，当它们表示truckSpinner之类的东西时会有所帮助，例如，因为当我看到此名称时，我知道这是我指定为选择卡车的Spinner 。