この1行でアプリがクラッシュするのはなぜですか？それは、クリック可能なセットでも起こります。線がなければ、それは問題ありませんが、それがあれば、それは活動にさえ入りません。
continueButton.setEnabled(false);
これがlogcatです。
09-30 16:05:09.352: E/AndroidRuntime(755): FATAL EXCEPTION: main
09-30 16:05:09.352: E/AndroidRuntime(755): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mangodeveloper.mcathomie/com.mangodeveloper.mcathomie.McatActivityGame}: java.lang.NullPointerException
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.os.Handler.dispatchMessage(Handler.java:99)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.os.Looper.loop(Looper.java:123)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.ActivityThread.main(ActivityThread.java:3683)
09-30 16:05:09.352: E/AndroidRuntime(755): at java.lang.reflect.Method.invokeNative(Native Method)
09-30 16:05:09.352: E/AndroidRuntime(755): at java.lang.reflect.Method.invoke(Method.java:507)
09-30 16:05:09.352: E/AndroidRuntime(755): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
09-30 16:05:09.352: E/AndroidRuntime(755): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
09-30 16:05:09.352: E/AndroidRuntime(755): at dalvik.system.NativeStart.main(Native Method)
09-30 16:05:09.352: E/AndroidRuntime(755): Caused by: java.lang.NullPointerException
09-30 16:05:09.352: E/AndroidRuntime(755): at com.mangodeveloper.mcathomie.McatActivityGame.onCreate(McatActivityGame.java:40)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-30 16:05:09.352: E/AndroidRuntime(755): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
09-30 16:05:09.352: E/AndroidRuntime(755): ... 11 more
これが今のところ全体の活動です：
package com.mangodeveloper.mcathomie;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;
public class McatActivityGame extends Activity {
private static int GAME_PREFERENCES_MAXROUNDS = 1, GAME_PREFERENCES_CURRENTROUND;
private Cursor c;
private RadioGroup radioGrp;
private Button continueButton, pauseButton, explainButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
radioGrp = (RadioGroup) findViewById(R.id.radioGroup1);
continueButton = (Button) findViewById(R.id.button_continue);
pauseButton = (Button) findViewById(R.id.button_pause);
explainButton = (Button)findViewById(R.id.button_explanation);
setContentView(R.layout.activity_game);
McatDatabase dbHelper = new McatDatabase(this);
c = dbHelper.getQuestions();
c.moveToFirst();
fillQuestions();
continueButton.setEnabled(false);
// radioGrp.setOnClickListener(new OnClickListener() {
//
// public void onClick(View v) {
// continueButton.setEnabled(true);
// }
// });
// continueButton.setOnClickListener(new OnClickListener() {
// public void onClick(View v) {
// int selectedId = radioGrp.getCheckedRadioButtonId();
// RadioButton radioBttnSelected = (RadioButton) findViewById(selectedId);
// if (radioBttnSelected.getText() == answer1) {
// Toast.makeText(McatActivityGame.this, "Correct Answer!", Toast.LENGTH_SHORT).show();
// }else{Toast.makeText(McatActivityGame.this, "Not correct, please try again", Toast.LENGTH_SHORT).show();
// }
// }
// });
// nextquestionButton.setOnClickListener(new OnClickListener() {
//
// public void onClick(View v) {
// GAME_PREFERENCES_CURRENTROUND++;
// GAME_PREFERENCES_MAXROUNDS = getIntent().getExtras().getInt("MAXROUNDS");
//
// if (GAME_PREFERENCES_CURRENTROUND > GAME_PREFERENCES_MAXROUNDS) {
// Toast.makeText(McatActivityGame.this, "Alert Dialog stuff", Toast.LENGTH_SHORT).show();
// }else{
// c.moveToNext();
// fillQuestions();
// }
// }
// });
//
}
private void fillQuestions() {
// shuffle questions
List<String> shuffAnswr = new ArrayList<String>(4);
shuffAnswr.add(c.getString(3));
shuffAnswr.add(c.getString(4));
shuffAnswr.add(c.getString(5));
shuffAnswr.add(c.getString(6));
Collections.shuffle(shuffAnswr);
// instantiate
TextView questionTv = (TextView) findViewById(R.id.textView0);
RadioButton rd0 = (RadioButton)findViewById(R.id.radio0),
rd1 = (RadioButton)findViewById(R.id.radio1),
rd2 = (RadioButton)findViewById(R.id.radio2),
rd3 = (RadioButton)findViewById(R.id.radio3);
// set questions
questionTv.setText(c.getString(2));
rd0.setText(shuffAnswr.get(0));
rd1.setText(shuffAnswr.get(1));
rd2.setText(shuffAnswr.get(2));
rd3.setText(shuffAnswr.get(3));
}
}