程序代码：

CREATE CURSOR tt (F1 C(10), F2 C(10), F3 I)
INSERT INTO tt VALUES ("ABC", "123456", 101)
INSERT INTO tt VALUES ("DEF", "654321", 202)
INSERT INTO tt VALUES ("GHI", "456123", 303)
GO TOP 
of = CREATEOBJECT("form1")
of.show(1)
RETURN

DEFINE CLASS form1 as Form
    ADD OBJECT grid1 as myGrid
    ADD OBJECT text1 as textbox WITH top = 210    && 增加了一个文本框控件，是为了验证活动控件为文本框时，双击表格行是否能切换到单元格
ENDDEFINE

DEFINE CLASS myGrid as Grid 
    AllowCellSelection = .f.
    DblTimes = 0        && 用于判断是否首次双击
    PROCEDURE DblClick
        LOCAL oo as TextBox,aTemp[1]
        AMOUSEOBJ(aTemp)
        oo = aTemp[1]
        IF VARTYPE(oo) = 'O' AND oo.BaseClass = 'Textbox'
            THIS.AllowCellSelection = .t.
            THIS.ReadOnly = .f.
            oo.Parent.SelectOnEntry = .f.        && 首次双击时不选择单元格，保持与再次双击时效果一致
            oo.SetFocus
        ENDIF
    ENDPROC
    PROCEDURE AfterRowColChange(nColIndex)
        IF THIS.DblTimes != 0
            THIS.AllowCellSelection = .f.
        ENDIF
        THIS.DblTimes = 1  
    ENDPROC
    PROCEDURE When
        THIS.DblTimes = 0    && 表格获得焦点时，初始化双击标识
    ENDPROC
ENDDEFINE