小编use*_*725的帖子

我正在尝试在我的onClick(View v)XML中调用该方法,但不能与Fragment一起使用.这是错误.

01-17 12:38:36.840: E/AndroidRuntime(4171): java.lang.IllegalStateException: 
Could not find a method insertIntoDb(View) in the activity class main.MainActivity 
for onClick handler on view class android.widget.Button with id 'btn_conferma'

MainActivity.java

public void insertIntoDb(View v) {
...
} 

xml代码

<Button
        android:id="@id/btn_conferma"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0.0dip"
        android:layout_height="45dp"
        android:layout_marginLeft="2dp"
        android:layout_weight="1.0"
        android:background="@drawable/bottoni"
        android:gravity="center_horizontal|center_vertical"
        android:onClick="insertIntoDb"
        android:text="SALVA"
        android:textColor="#ffffff"
        android:textSize="16sp" />

我有一个DatePickerDialog,我想只查看月和年.我该如何更改此代码？

public void chooseDate2(View v) {
    new DatePickerDialog(
        act.this,
        d1,
        dateAndTime1.get(Calendar.YEAR) + 2,
        dateAndTime1.get(Calendar.MONTH),
        dateAndTime1.get(Calendar.DAY_OF_MONTH)
    ).show();
}
private void updateLabel2() {
    scadenza.setText(fmtDateAndTime.format(dateAndTime1.getTime()));           
}
DatePickerDialog.OnDateSetListener d1=new DatePickerDialog.OnDateSetListener() {
    public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        dateAndTime1.set(Calendar.YEAR, year);
        dateAndTime1.set(Calendar.MONTH, monthOfYear);
        dateAndTime1.set(Calendar.DAY_OF_MONTH, dayOfMonth);
        updateLabel2();
    }
};

谢谢

我有一个查询从2个表中获取数据.它可以工作,但是如果没有值,则两个SUM返回NULL.我怎样才能得到零呢？

SELECT SUM(g.field1), 
       SUM(g.field2), 
       c._id, 
       c.field_1, 
       c.field_3 
  FROM Table1 g 
  JOIN Tabel2 c 
 WHERE ( c.field_1 = g.field5 )