android - java.lang.IllegalStateException : Could not execute method of the activity 错误

Question

我正在以测验的形式开发这个简单的应用程序，用户可以在其中获得问题和 4 个选项。这些问题是从 SQLite 数据库中提取的。在我的 succ.java Activity 中，我显示问题并在单击下一步按钮时获取下一个问题。

现在在模拟器上运行它时，如果我不选择 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，我考虑检查我的 succ.java 页面，如果没有选择 ae 选项，则从具有相同问题 ID 的数据库中获取问题，如果我选择了其中一个，则使用下一个问题 ID 获取问题。

但它仍然无法正常工作，我已经尝试了所有可能的方法。我正在附上我的 succ.java。以及 logcat。

succ.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

Answer 1

if i dont select any of the 4 radio buttons my app ultimately stops and i have to force close.

根据您的代码，它正在按预期发生。

您犯的最大错误是在检查单选按钮时初始化单选按钮。下面是您编写的 fragment 。

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);

因此，如果场景是如果您不选择任何单选按钮，它们都不会被初始化，然后如果单击下一步按钮，您显然会得到 NPE。

if(op1.isChecked()||op2.isChecked()||op3.isChecked()||op4.isChecked())
    {
        question=questionAdapter.showQues(token_page);
    }

所以解决方案是在 onCreate 中初始化所有单选按钮。

下面是修改后的 fragment 。

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);

    op1 = (RadioButton) findViewById(R.id.op1Text);
    op2 = (RadioButton) findViewById(R.id.op2Text);
    op3 = (RadioButton) findViewById(R.id.op3Text);
    op4 = (RadioButton) findViewById(R.id.op4Text); 


    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) {



    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);
    }
}
}