在我的应用程序中，我正在尝试使用单选按钮实现小测验，我正在尝试在 viewpager 中实现，现在我的问题是我在 viewpager 中显示了问题，我试图在移动到下一页之前检查条件，需要根据条件显示 toast 消息。但是我遇到了错误并且应用程序崩溃了。 我在下面发布了我的代码部分
t_vPager.setOnPageChangeListener(new OnPageChangeListener()
{
@Override
public void onPageSelected(int position)
{
// TODO Auto-generated method stub
System.out.println("checking");
switch(position)
{
case 0:
System.out.println("question1 ");
id=radioanswergroup.getCheckedRadioButtonId();
radioanswerButton = (RadioButton)findViewById(id);
System.out.println("answer--"+radioanswerButton.getText());
break;
case 1:
System.out.println("question2 ");
break;
case 2:
System.out.println("question3 ");
break;
case 3:
System.out.println("question4 ");
break;
}
}
else
{
System.out.println("verify the answer");
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2)
{
// TODO Auto-generated method stub
}
@Override
public void onPageScrollStateChanged(int arg0)
{
// TODO Auto-generated method stub
}
});
日志错误
03-31 13:34:18.743: E/InputEventReceiver(11605): Exception dispatching input event.
03-31 13:34:18.743: E/MessageQueue-JNI(11605): Exception in MessageQueue callback: handleReceiveCallback
03-31 13:34:18.758: E/MessageQueue-JNI(11605): java.lang.NullPointerException
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at com.example.instantenglish.Todaytest$Dailytask$1.onPageSelected(Todaytest.java:234)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.support.v4.view.ViewPager.scrollToItem(ViewPager.java:567)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:551)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2015)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.View.dispatchTouchEvent(View.java:7350)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2412)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2147)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2139)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1476)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.app.Activity.dispatchTouchEvent(Activity.java:2487)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2087)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.View.dispatchPointerEvent(View.java:7535)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3415)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3347)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4456)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4434)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4538)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.os.MessageQueue.nativePollOnce(Native Method)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.os.MessageQueue.next(MessageQueue.java:125)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.os.Looper.loop(Looper.java:124)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at android.app.ActivityThread.main(ActivityThread.java:4921)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at java.lang.reflect.Method.invokeNative(Native Method)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at java.lang.reflect.Method.invoke(Method.java:511)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
03-31 13:34:18.758: E/MessageQueue-JNI(11605): at dalvik.system.NativeStart.main(Native Method)
03-31 13:34:18.763: D/AndroidRuntime(11605): Shutting down VM
03-31 13:34:18.763: W/dalvikvm(11605): threadid=1: thread exiting with uncaught exception (group=0x41e0b2a0)
03-31 13:34:18.773: E/AndroidRuntime(11605): FATAL EXCEPTION: main
03-31 13:34:18.773: E/AndroidRuntime(11605): java.lang.NullPointerException
03-31 13:34:18.773: E/AndroidRuntime(11605): at com.example.instantenglish.Todaytest$Dailytask$1.onPageSelected(Todaytest.java:234)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.support.v4.view.ViewPager.scrollToItem(ViewPager.java:567)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:551)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2015)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.View.dispatchTouchEvent(View.java:7350)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2412)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2147)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2418)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2161)
03-31 13:34:18.773: E/AndroidRuntime(11605): at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2139)
03-31 13:34:18.773: E/AndroidRuntime(11605): at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1476)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.app.Activity.dispatchTouchEvent(Activity.java:2487)
03-31 13:34:18.773: E/AndroidRuntime(11605): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2087)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.View.dispatchPointerEvent(View.java:7535)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewRootImpl.deliverPointerEvent(ViewRootImpl.java:3415)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:3347)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:4456)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:4434)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:4538)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:171)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.os.MessageQueue.nativePollOnce(Native Method)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.os.MessageQueue.next(MessageQueue.java:125)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.os.Looper.loop(Looper.java:124)
03-31 13:34:18.773: E/AndroidRuntime(11605): at android.app.ActivityThread.main(ActivityThread.java:4921)
03-31 13:34:18.773: E/AndroidRuntime(11605): at java.lang.reflect.Method.invokeNative(Native Method)
03-31 13:34:18.773: E/AndroidRuntime(11605): at java.lang.reflect.Method.invoke(Method.java:511)
03-31 13:34:18.773: E/AndroidRuntime(11605): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1027)
03-31 13:34:18.773: E/AndroidRuntime(11605): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)
03-31 13:34:18.773: E/AndroidRuntime(11605): at dalvik.system.NativeStart.main(Native Method)
这是我的完整代码
import java.util.ArrayList;
import java.util.Collections;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Switch;
import android.widget.Toast;
import android.widget.RadioGroup.OnCheckedChangeListener;
import android.widget.TextView;
public class Todaytest extends Activity implements OnClickListener
{
//urls
String url="link";
//json array
JSONArray jarray;
//Array list
ArrayList<String> tst_alquestion = new ArrayList<String>();
ArrayList<String> tst_alcorrectanswer = new ArrayList<String>();
ArrayList<String> tst_alwronganswer1 = new ArrayList<String>();
ArrayList<String> tst_alwronganswer2 = new ArrayList<String>();
ArrayList<String> tst_alwronganswer3 = new ArrayList<String>();
ArrayList<String> tst_alwronganswer4 = new ArrayList<String>();
ArrayList<String> shufanswer=new ArrayList<String>();
//Radio button
RadioGroup radioanswergroup;
RadioButton radioanswerButton,btn1,btn2,btn3,btn4;
int id,qid=0;
//text view
TextView question;
ViewPager t_vPager;
PagerAdapter t_padapter;
@Override
protected void onCreate(Bundle savedInstanceState)
{
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.test);
t_vPager = (ViewPager) findViewById(R.id.ttpager);
question=(TextView)findViewById(R.id.qst);
radioanswergroup=(RadioGroup)findViewById(R.id.radioanswer);
btn1=(RadioButton)findViewById(R.id.btn1);
btn2=(RadioButton)findViewById(R.id.btn2);
btn3=(RadioButton)findViewById(R.id.btn3);
btn4=(RadioButton)findViewById(R.id.btn4);
new Dailytask().execute();
//questionview();
}
@Override
public void onClick(View v)
{
// TODO Auto-generated method stub
}
private class Dailytask extends AsyncTask<String, String, JSONObject>
{
private ProgressDialog pDialog;
@Override
protected void onPreExecute()
{
super.onPreExecute();
pDialog = new ProgressDialog(Todaytest.this);
pDialog.setMessage("Loading Assessment ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected JSONObject doInBackground(String... args)
{
Json j = new Json();
// Getting JSON from URL
JSONObject json = j.getJSONFromUrl(url);
return json;
}
@Override
protected void onPostExecute(JSONObject json)
{
System.out.println("---------------return today test json------------"+json);
pDialog.dismiss();
try
{
// Getting JSON Array from URL
JSONObject jobj = json.getJSONObject("response");
jarray = jobj.getJSONArray("Test");
System.out.println("json array length"+jarray.length());
for (int i = 0; i < jarray.length(); i++)
{
JSONObject data = jarray.getJSONObject(i);
// Storing JSON item in a Variable
tst_alquestion.add(data.getString("question"));
tst_alcorrectanswer.add(data.getString("correctanswer"));
tst_alwronganswer1.add(data.getString("wronganswer1"));
tst_alwronganswer2.add(data.getString("wronganswer2"));
tst_alwronganswer3.add(data.getString("wronganswer3"));
tst_alwronganswer4.add(data.getString("wronganswer4"));
System.out.println("correct answer------------>"+tst_alcorrectanswer);
System.out.println("wroang ans1------------>"+tst_alwronganswer1);
System.out.println("wroang ans2------------>"+tst_alwronganswer2);
System.out.println("wroang ans3------------>"+tst_alwronganswer3);
System.out.println("wroang ans4------------>"+tst_alwronganswer4);
}
}
catch(Exception e)
{
}
t_padapter = new testadapter(Todaytest.this, tst_alquestion,tst_alcorrectanswer ,tst_alwronganswer1,tst_alwronganswer2,tst_alwronganswer3,tst_alwronganswer4);
t_vPager.setAdapter(t_padapter);
t_vPager.setOnPageChangeListener(new OnPageChangeListener()
{
@Override
public void onPageSelected(int position)
{
// TODO Auto-generated method stub
System.out.println("checking"+position);
//Toast.makeText(getApplicationContext(), "please answer for above questions",Toast.LENGTH_SHORT ).show();
switch(position)
{
case 0:
System.out.println("question1 ");
id=radioanswergroup.getCheckedRadioButtonId();
radioanswerButton = (RadioButton)findViewById(id);
System.out.println("answer--"+radioanswerButton.getText());
break;
case 1:
System.out.println("question2 ");
break;
case 2:
System.out.println("question3 ");
break;
case 3:
System.out.println("question4 ");
break;
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2)
{
// TODO Auto-generated method stub
}
@Override
public void onPageScrollStateChanged(int arg0)
{
// TODO Auto-generated method stub
}
});
}
}
}
测试.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:background="#F5DA81" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="15dp"
android:background="#FFFFFF"
android:orientation="vertical" >
<android.support.v4.view.ViewPager
android:id="@+id/ttpager"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
//测试适配器
package com.example.instantenglish;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import org.apache.http.util.ByteArrayBuffer;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Parcelable;
import android.os.StrictMode;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;
public class testadapter extends PagerAdapter
{
// Declare Variables
Context context;
ArrayList<String> question;
ArrayList<String> answer;
ArrayList<String> ans1;
ArrayList<String> ans2;
ArrayList<String> ans3;
ArrayList<String> ans4;
int[] flag;
LayoutInflater inflater;
public testadapter(Todaytest tt, ArrayList<String> tst_alquestion,
ArrayList<String> tst_alcorrectanswer,
ArrayList<String> tst_alwronganswer1,
ArrayList<String> tst_alwronganswer2,
ArrayList<String> tst_alwronganswer3,
ArrayList<String> tst_alwronganswer4)
{
// TODO Auto-generated constructor stub
this.context=tt;
this.question=tst_alquestion;
this.answer=tst_alcorrectanswer;
this.ans1=tst_alwronganswer1;
this.ans2=tst_alwronganswer2;
this.ans3=tst_alwronganswer3;
this.ans4=tst_alwronganswer4;
}
@Override
public int getCount() {
return question.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == ((LinearLayout) object);
}
@Override
public Object instantiateItem(ViewGroup container, int position)
{
// Declare Variables
TextView txtquestion;
RadioButton radioanswerButton,btn1,btn2,btn3,btn4,btn5; //TextView txtpopulation;
RadioGroup radioanswergroup;
inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View itemView = inflater.inflate(R.layout.todaytest, container,
false);
// Locate the TextViews in viewpager_item.xml
txtquestion = (TextView) itemView.findViewById(R.id.qst);
radioanswergroup=(RadioGroup)itemView.findViewById(R.id.radioanswer);
btn1=(RadioButton)itemView.findViewById(R.id.btn1);
btn2=(RadioButton)itemView.findViewById(R.id.btn2);
btn3=(RadioButton)itemView.findViewById(R.id.btn3);
btn4=(RadioButton)itemView.findViewById(R.id.btn4);
btn5=(RadioButton)itemView.findViewById(R.id.btn5);
// Capture position and set to the TextViews
txtquestion.setText(question.get(position));
btn1.setText(answer.get(position));
btn2.setText(ans1.get(position));
btn3.setText(ans2.get(position));
btn4.setText(ans3.get(position));
btn5.setText(ans4.get(position));
//txtpopulation.setText(population[position]);
// Locate the ImageView in viewpager_item.xml
// Add viewpager_item.xml to ViewPager
((ViewPager) container).addView(itemView);
return itemView;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
// Remove viewpager_item.xml from ViewPager
((ViewPager) container).removeView((LinearLayout) object);
}
@Override
public void restoreState(Parcelable arg0, ClassLoader arg1) {
// TODO Auto-generated method stub
}
@Override
public Parcelable saveState() {
// TODO Auto-generated method stub
return null;
}
@Override
public void startUpdate(View arg0) {
// TODO Auto-generated method stub
}
}
测试适配器 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"
android:background="#F5DA81">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="#FFFFFF" >
<TextView
android:id="@+id/qst"
android:layout_width="200dp"
android:layout_height="50dp"
android:layout_gravity="center"
android:layout_marginTop="20dp"
android:background="@drawable/txtview"
android:gravity="center"
android:text="Questions"
android:textColor="#000000"
android:textStyle="bold" />
<TableRow
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginLeft="25dp"
android:layout_marginRight="25dp"
android:layout_marginTop="25dp" >
<RadioGroup
android:id="@+id/radioanswer"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<RadioButton
android:id="@+id/btn1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/rbtn1"
android:textColor="#000000"/>
<RadioButton
android:id="@+id/btn2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="@string/rbtn2"
android:textColor="#000000" />
<RadioButton
android:id="@+id/btn3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="@string/rbtn3"
android:textColor="#000000" />
<RadioButton
android:id="@+id/btn4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="@string/rbtn4"
android:textColor="#000000" />
<RadioButton
android:id="@+id/btn5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="@string/rbtn5"
android:textColor="#000000" />
</RadioGroup>
</TableRow>
</LinearLayout>
</LinearLayout>
最佳答案
如您的详细信息所示，您正在使用 getCheckedRadioButtonId() 但在您的 xml 中没有检查 RadioButton。所以只需检查如下所示的 RedioButton
<RadioButton
android:id="@+id/btn3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"
android:text="@string/rbtn3"
android:checked="true"
android:textColor="#000000" />
并且在获取带有选中 id 的按钮之前也使用条件。像下面这样使用
int id=radioanswergroup.getCheckedRadioButtonId();
if(id>0)
radioanswerButton = (RadioButton)findViewById(id);
关于android - 如何在移动到 viewpager 中的下一页之前检查条件，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22755806/