我正在以测验的形式开发这个简单的应用程序，用户可以获得问题和 4 个选项。这些问题是从 SQLite DB 中获取的。在我的 succ.java 活动中，我显示问题并在单击下一个按钮时获取下一个问题。
现在在模拟器上运行它时，如果我没有选择 4 个单选按钮中的任何一个，我的应用程序最终会停止，我必须强制关闭。为了解决这个问题，我想在我的 succ.java 页面中检查，如果两个选项 ae 都没有选择从 db 中获取具有相同问题 ID 的问题，并且如果我选择了任何一个选项来获取具有下一个问题 ID 的问题。
但这仍然行不通，我已经尝试了我可以做的一切。我附上了我的 succ.java。还有logcat。
成功的java
public class succ extends Activity {
private static String[] response = new String[10];
RadioButton op1,op2,op3,op4;
private int token_page;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mainquespage);
int qno=0;
String ques="";
String ans1="";
String ans2="";
String ans3="";
String ans4="";
//int token=0;
Bundle extras=getIntent().getExtras();
//token=extras.getInt("SESS_ID");
ques=extras.getString("KEY_QUES");
ans1=extras.getString("KEY_ANS1");
ans2=extras.getString("KEY_ANS2");
ans3=extras.getString("KEY_ANS3");
ans4=extras.getString("KEY_ANS4");
qno=extras.getInt("KEY_ID");
token_page=qno+1;
TextView quesnumber=(TextView)findViewById(R.id.quesIDTEXT);
quesnumber.setText("QUESTION: "+ qno );
TextView quescont=(TextView)findViewById(R.id.quesContText);
quescont.setText(ques);
TextView opt1=(TextView)findViewById(R.id.op1Text);
opt1.setText(ans1);
TextView opt2=(TextView)findViewById(R.id.op2Text);
opt2.setText(ans2);
TextView opt3=(TextView)findViewById(R.id.op3Text);
opt3.setText(ans3);
TextView opt4=(TextView)findViewById(R.id.op4Text);
opt4.setText(ans4);
}
public void onRadioButtonClicked(View view) {
op1 = (RadioButton) findViewById(R.id.op1Text);
op2 = (RadioButton) findViewById(R.id.op2Text);
op3 = (RadioButton) findViewById(R.id.op3Text);
op4 = (RadioButton) findViewById(R.id.op4Text);
if(op1.isChecked())
{
response[token_page-2]=op1.getText().toString();
}
else if(op2.isChecked()){
response[token_page-2]=op2.getText().toString();
}
else if(op3.isChecked()){
response[token_page-2]=op3.getText().toString();
}
else if(op4.isChecked()){
response[token_page-2]=op4.getText().toString();
}
else
response[token_page-2]="";
}
public void nextClick(View view)
{
final Context context=this;
Question question=new Question();
MyAdapter questionAdapter=new MyAdapter(this);
if(token_page!=11)
{
questionAdapter.open();
if(op1.isChecked()||op2.isChecked()||op3.isChecked()||op4.isChecked())
{
question=questionAdapter.showQues(token_page);
}
else
{
question=questionAdapter.showQues(token_page-1);
}
//please note when i'm just writing: question=questionAdapter.showQues(token_page) //without checking for the selection of radio buttons i get the error i the end after the //last question is answered but when i'm checking it here and using if els then am getting //an error on the same screen. i'm stuck on this since forever. HELP !!
questionAdapter.close();
int qno;
String ques;
String ans1;
String ans2;
String ans3;
String ans4;
qno=question.getQno();
ques=question.getQues();
ans1=question.getAns1();
ans2=question.getAns2();
ans3=question.getAns3();
ans4=question.getAns4();
Intent intent=new Intent(context, succ.class);
intent.putExtra("KEY_ID", qno);
intent.putExtra("KEY_QUES",ques);
intent.putExtra("KEY_ANS1",ans1);
intent.putExtra("KEY_ANS2",ans2);
intent.putExtra("KEY_ANS3",ans3);
intent.putExtra("KEY_ANS4",ans4);
startActivity(intent);
}//token_page
else
{
Toast.makeText(this, "FINISHED", Toast.LENGTH_LONG).show();
Bundle b=new Bundle();
b.putStringArray("ARRAY", response);
Intent i=new Intent(context, result.class);
i.putExtras(b);
startActivity(i);
}
}
}
LOGCAT
06-26 11:26:48.401: D/opendb(357): EXIST
06-26 11:26:52.321: W/KeyCharacterMap(357): No keyboard for id 0
06-26 11:26:52.321: W/KeyCharacterMap(357): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
06-26 11:26:53.781: D/dalvikvm(357): GC_EXTERNAL_ALLOC freed 122K, 51% free 2699K/5447K, external 2128K/2137K, paused 63ms
06-26 11:26:59.923: W/KeyCharacterMap(357): No keyboard for id 0
06-26 11:26:59.923: W/KeyCharacterMap(357): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
06-26 11:29:49.512: D/opendb(478): EXIST
06-26 11:29:58.981: D/AndroidRuntime(478): Shutting down VM
06-26 11:29:58.981: W/dalvikvm(478): threadid=1: thread exiting with uncaught exception (group=0x40015560)
06-26 11:29:59.011: E/AndroidRuntime(478): FATAL EXCEPTION: main
06-26 11:29:59.011: E/AndroidRuntime(478): java.lang.IllegalStateException: Could not execute method of the activity
06-26 11:29:59.011: E/AndroidRuntime(478): at android.view.View$1.onClick(View.java:2144)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.view.View.performClick(View.java:2485)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.view.View$PerformClick.run(View.java:9080)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.os.Handler.handleCallback(Handler.java:587)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.os.Handler.dispatchMessage(Handler.java:92)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.os.Looper.loop(Looper.java:123)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.app.ActivityThread.main(ActivityThread.java:3683)
06-26 11:29:59.011: E/AndroidRuntime(478): at java.lang.reflect.Method.invokeNative(Native Method)
06-26 11:29:59.011: E/AndroidRuntime(478): at java.lang.reflect.Method.invoke(Method.java:507)
06-26 11:29:59.011: E/AndroidRuntime(478): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
06-26 11:29:59.011: E/AndroidRuntime(478): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
06-26 11:29:59.011: E/AndroidRuntime(478): at dalvik.system.NativeStart.main(Native Method)
06-26 11:29:59.011: E/AndroidRuntime(478): Caused by: java.lang.reflect.InvocationTargetException
06-26 11:29:59.011: E/AndroidRuntime(478): at java.lang.reflect.Method.invokeNative(Native Method)
06-26 11:29:59.011: E/AndroidRuntime(478): at java.lang.reflect.Method.invoke(Method.java:507)
06-26 11:29:59.011: E/AndroidRuntime(478): at android.view.View$1.onClick(View.java:2139)
06-26 11:29:59.011: E/AndroidRuntime(478): ... 11 more
06-26 11:29:59.011: E/AndroidRuntime(478): Caused by: java.lang.NullPointerException
06-26 11:29:59.011: E/AndroidRuntime(478): at my.pkg.newquiz.succ.nextClick(succ.java:98)
06-26 11:29:59.011: E/AndroidRuntime(478): ... 14 more
06-26 11:30:02.821: I/Process(478): Sending signal. PID: 478 SIG: 9