try 
    { 
        this.DataGrid1.DataBind(); 
    } 
    catch 
    { 
        //判斷當前頁的索引是否正確 
        if(DataGrid1.CurrentPageIndex < 0 || DataGrid1.CurrentPageIndex>=DataGrid1.PageCount) 
        { 
            DataGrid1.CurrentPageIndex = DataGrid1.CurrentPageIndex -1; 
        } 
        this.DataGrid1.DataBind(); 
    }