无法启动活动组件信息：java.lang.NullPointerException
我正在为我的学位构建一个android应用程序。我需要从电话中获取所有联系人 开始申请（稍后我还需要收到电子邮件等）。所以我用了两门课 敏感度无法启动活动组件信息：java.lang.NullPointerException,java,android,Java,Android,我正在为我的学位构建一个android应用程序。我需要从电话中获取所有联系人 开始申请（稍后我还需要收到电子邮件等）。所以我用了两门课 敏感度 public class Degree_thesisActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.o
public class Degree_thesisActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
GetFromPhone gf = new GetFromPhone();
gf.getContacts();
}
class GetFromPhone extends Activity {
public void getContacts() {
// TODO Auto-generated method stub
/**Declare a Contacts Cursor which have a list of all contacts*/
Cursor cursor = getContentResolver().query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
/**Move while cursor has another istance to process*/
while(cursor.moveToNext()){
/**Get the contact name pointed by cursor at that time*/
cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
String contactID = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
/**show the contact pointed.THIS WILL BE MODIFIED FURTHER!!!!*/
new AlertDialog.Builder(this)
.setMessage(contactID)
.setNeutralButton("ok", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// TODO Auto-generated method stub
}
})
.show();
}
}
为什么？任何人都可以帮助我？由于类
GetFromPhone活动new活动