Cursor cursor = db.rawQuery( //空指针
"select * from user_info where username=?",
new String[] { text });
while (cursor.moveToNext()) {
TextView username=(TextView)findViewById(R.id.nickname);
username.setText(cursor.getString(1));
EditText phone=(EditText)findViewById(R.id.phone);
phone.setText(cursor.getString(4));
cursor.close();
}