此 android 活动未运行。谁能帮帮我。它显示以下错误。当我单击它开始另一个活动时,它不会运行。
我找不到这个错误。
任何人都可以解决它?
错误:致命异常:主要
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testingandroid/com.example.testingandroid.SumsMain}: java.lang.NullPointerException
07-26 12:57:22.958: E/AndroidRuntime(791): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
代码
package com.example.testingandroid;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.RadioButton;
public class SelectTitle extends Activity implements android.view.View.OnClickListener{
public int entryNo;
RadioButton r1;RadioButton r2;RadioButton r3;RadioButton r4;
RadioButton r5;RadioButton r6;RadioButton r7;RadioButton r8;
RadioButton r9;RadioButton r10;RadioButton r11;RadioButton r12;
RadioButton r13;
int determiner;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_select_title);
r1 = (RadioButton) findViewById(R.id.MasteryPack);
r2 = (RadioButton) findViewById(R.id.Simplification);
r3 = (RadioButton) findViewById(R.id.FractionsandRatios);
r4 = (RadioButton) findViewById(R.id.Number);
r5 = (RadioButton) findViewById(R.id.Average);
r6 = (RadioButton) findViewById(R.id.TimeandWork);
r7 = (RadioButton) findViewById(R.id.TimeandDistance);
r8 = (RadioButton) findViewById(R.id.Interest);
r9 = (RadioButton) findViewById(R.id.Measurement);
r10 = (RadioButton) findViewById(R.id.Percentage);
r11 = (RadioButton) findViewById(R.id.BoatandTrain);
r12 = (RadioButton) findViewById(R.id.Practice);
r1.setOnClickListener(this);
r2.setOnClickListener(this);
r3.setOnClickListener(this);
r4.setOnClickListener(this);
r5.setOnClickListener(this);
r6.setOnClickListener(this);
r7.setOnClickListener(this);
r8.setOnClickListener(this);
r9.setOnClickListener(this);
r10.setOnClickListener(this);
r11.setOnClickListener(this);
r12.setOnClickListener(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.select_title, menu);
return true;
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.MasteryPack:
Intent nextScreen = new Intent(getApplicationContext(), SumsMain.class);
nextScreen.putExtra("determiner", 1);
startActivity(nextScreen);
break;
case R.id.Simplification:
Intent nextScreen1 = new Intent(getApplicationContext(), SumsMain.class);
//String "determiner" = null;
nextScreen1.putExtra("determiner", 2);
startActivity(nextScreen1);
break;
case R.id.FractionsandRatios:
Intent nextScreen2 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen2.putExtra("determiner", 3);
startActivity(nextScreen2);
break;
case R.id.Number:
Intent nextScreen3 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen3.putExtra("determiner", 4);
startActivity(nextScreen3);
break;
case R.id.Average:
Intent nextScreen4 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen4.putExtra("determiner", 5);
startActivity(nextScreen4);
break;
case R.id.TimeandWork:
Intent nextScreen5 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen5.putExtra("determiner", 6);
startActivity(nextScreen5);
break;
case R.id.TimeandDistance:
Intent nextScreen6 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen6.putExtra("determiner", 7);
startActivity(nextScreen6);
break;
case R.id.Interest:
Intent nextScreen7 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen7.putExtra("determiner", 8);
startActivity(nextScreen7);
break;
case R.id.Measurement:
Intent nextScreen8 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen8.putExtra("determiner", 9);
startActivity(nextScreen8);
break;
case R.id.Percentage:
Intent nextScreen9 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen9.putExtra("determiner", 10);
startActivity(nextScreen9);
break;
case R.id.BoatandTrain:
Intent nextScreen10 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen10.putExtra("determiner", 11);
startActivity(nextScreen10);
break;
case R.id.Practice:
Intent nextScreen11 = new Intent(getApplicationContext(), SumsMain.class);
nextScreen11.putExtra("determiner", 12);
startActivity(nextScreen11);
break;
}
}
}