Delphi CxGrid 汇总（3）

列  
解决：
      <aColumn>.GroupIndex   :=   -1;  
      <aColumn>.Visible   :=   True;
****************************************************************************
39 保存修改到数据库
解决：
procedure   <aForm>.FormClose(Sender:   TObject;   var   Action:   TCloseAction);  
begin  
if   (<aGrid>.FocusedView <> nil)
and   (<aGrid>.FocusedView.DataController.EditState <> []) then  
          <aGrid>.FocusedView.DataController.Post;  
end;
****************************************************************************
40 设置内置右键菜单
解决：
内置右键菜单包括二个菜单:cxGridStdHeaderMenu,   TcxGridStdFooterMenu  

 uses   cxGridStdPopupMenu;

 procedure   TForm1.cxGridPopupMenu1Popup(ASenderMenu:   TComponent;
       AHitTest:   TcxCustomGridHitTest;   X,   Y:   Integer;   var   AllowPopup:   Boolean);
 begin
       if   ASenderMenu   is   TcxGridStdHeaderMenu   then
           TcxGridStdHeaderMenu(ASenderMenu).OnPopup   :=   StdHeaderMenuPopup;
 end;

 procedure   TForm1.StdHeaderMenuPopup(Sender:   TObject);
 var
       I:   Integer;
 begin
       with   TcxGridStdHeaderMenu(Sender).Items   do
           for   I   :=   0   to   Count   -   1   do
               if   Items[I].Caption   =   'Group   By   Box'   then
               begin
                   Items[I].Enabled   :=   False;
                   System.Break;
               end
 end;

****************************************************************************
41 得到选中记录的值
解决：

 1)   View.DataController.DataModeController.GridMode   =   False时

       RecIdx   :=   View.Controller.SelectedRecords[i].RecordIndex;
       ColIdx   :=   View.DataController.GetItemByFieldName(AFieldName).Index;
       OutputVal   :=   View.DataController.Values[RecIdx,   ColIdx];

       //RecID   :=   View.DataController.GetRecordId(RecIdx);
       //OutputVal   :=   ADataSet.Lookup(View.DataController.KeyFieldNames,   RecID,   AFieldName);

 2)   View.DataController.DataModeController.GridMode   =   True时
       Bkm   :=   View.DataController.GetSelectedBookmark(ASelectedRecordIndex);
       if   ADataSet.BookmarkValid(TBookmark(Bkm))   then
       begin
           ADataSet.Bookmark   :=   TBookmark(Bkm);
           OutputVal   :=   ADataSet.FieldByName(AFieldName).Value;
       end;

       View.BeginUpdate;
       View.DataController.BeginLocate;
       try
           //   make   changes   here…
       finally
           View.DataController.EndLocate;
           View.EndUpdate;
       end;

****************************************************************************
42 在GridMode禁用内置的右键Footer菜单
解决：
uses   cxGridStdPopupMenu;  
   
procedure   cxGridPopupMenuOnPopup(...)  
begin  
      if   (ASenderMenu   is   TcxGridStdFooterMenu)   and  
              <GridView>.DataController.DataModeController.GridMode   then  
          AllowPopup   :=   False;  
end;
****************************************************************************
43 主从表任何时候只能展开一个组
解决：

 procedure   TForm1.ADetailDataControllerCollapsin(  ADataController:  TcxCustomDataController;

 ARecordIndex:   Integer;  var   AAllow:   Boolean);
 var
       I:   Integer;
       C:   Integer;
 begin
       AAllow   :=   False;
       C   :=   0;
       for   I   :=   0   to   ADataController.RecordCount   -   1   do
       begin
           if   ADataController.GetDetailExpanding(I)   then
               Inc(C);
           if   C   >   1   then
               AAllow   :=   True;
         end;
 end;

 procedure   TForm1.ADetailDataControllerExpanding(
       ADataController:   TcxCustomDataController;   ARecordIndex:   Integer;
       var   AAllow:   Boolean);
 begin
       ADataController.CollapseDetails;
 end;

 procedure   TForm1.FormCreate(Sender:   TObject);
 begin        cxGrid1DBTableView1.DataController.OnDetailExpanding:=ADetailDataControllerExpanding;         cxGrid1DBTableView1.DataController.OnDetailCollapsing:=ADetailDataControllerCollapsing;
 end;
 ****************************************************************************
 44 动态创建层次(Level)和视图(View)
 解决：
 var
       Grid:   TcxGrid;
       Level:   TcxGridLevel;
       View:   TcxGridDBTableView;
 begin
       //   Creates   a   Grid   instance
       Grid   :=   TcxGrid.Create(SomeOwner);
       Grid.Parent   :=   SomeParent;
       //   Creates   a   Level
       Level   :=   Grid.Levels.Add;
       Level.Name   :=   'SomeLevelName';
       //   Creates   a   View
       View   :=   Grid.CreateView(TcxGridDBTableView)   as   TcxGridDBTableView;
       View.Name   :=   'SomeViewName';
       //   …   and   binds   it   to   the   Level
       Level.GridView   :=   View;
       //   Hooks   up   the   View   to   the   data
       View.DataController.DataSource   :=   SomeDataSource;
       //   …   and   creates   all   columns
       View.DataController.CreateAllItems;
 end;

****************************************************************************
45 获得Group   Footer合计行对应的记录
解决：

 procedure   TForm1.cxGrid1DBTableView1CustomDrawFooterCell(
       Sender:   TcxGridTableView;   ACanvas:   TcxCanvas;
       AViewInfo:   TcxGridColumnHeaderViewInfo;   var   ADone:   Boolean);
 var
       ALevel,   ADataGroupIndex:   Integer;
       AGridRecord,   AGroupRecord:   TcxCustomGridRecord;
 begin
       if   AViewInfo   is   TcxGridRowFooterCellViewInfo   and    //   Row   footer
             (TcxGridDBColumn(AViewInfo.Column).DataBinding.FieldName   =   'Area')   then     //   Area   column
    begin
         AGridRecord:=   TcxGridRowFooterCellViewInfo(AViewInfo).GridRecord;
         ALevel:= TcxGridRowFooterCellViewInfo(AViewInfo).Container.GroupLevel;
 ADataGroupIndex:=Sender.DataController.Groups.DataGroupIndexByRowIndex[AGridRecord.Index];
          if   ADataGroupIndex   <>   -1   then
          begin
             AGroupRecord   :=   AGridRecord;
             while   AGroupRecord.Level   <>   ALevel   do
             AGroupRecord   :=   AGroupRecord.ParentRecord;
             AViewInfo.Text   :=   AGroupRecord.DisplayTexts[0];
          end;
      end;
 end;

****************************************************************************
46 访问过滤之后的记录
解决：
var  
      I:   Integer;  
begin  
      Memo1.Lines.Clear;  
      with   cxGrid1DBTableView1.DataController   do  
          for   I   :=   0   to   FilteredRecordCount   -   1   do  
              Memo1.Lines.Add(DisplayTexts[FilteredRecordIndex[I],   0]);  
end;

****************************************************************************
47 获得单元的Font
解决：
cxGrid1DBTableView1.ViewInfo.RecordsViewInfo.Items[1].GetCellViewInfoByItem(  
      cxGrid1DBTableView1Company).EditViewInfo.Font;
****************************************************************************
48 根据Level名称找到Level对象
解决：

 function   GetLevelByName(AGrid:   TcxGrid;   ALevelName:   string):   TcxGridLevel;

       function   LoopThroughLevels(ALevel:   TcxGridLevel;   ALevelName:   string):   TcxGridLevel;
       var
           I:   Integer;
       begin
           Result   :=   nil;
           for   I   :=   0   to   ALevel.Count   -   1   do
           begin
               if   ALevel[I].Name   =   ALevelName   then
               begin
                   Result   :=   ALevel[I];
                   Exit;
               end;
               if   ALevel[I].Count   >   0   then
               begin
                   Result   :=   LoopThroughLevels(ALevel[I],   ALevelName);
                   if   Result   <>   nil   then
                       Exit;
               end;
           end;
       end;

 var
       I:   Integer;
 begin
       Result   :=   nil;
       for   I   :=   0   to   AGrid.Levels.Count   -   1   do
       begin
           if   AGrid.Levels[I].Name   =   ALevelName   then
           begin
               Result   :=   AGrid.Levels[I];
               Exit;
           end;
           if   AGrid.Levels[I].Count   >   0   then
           begin
               Result   :=   LoopThroughLevels(AGrid.Levels[I],   ALevelName);
               if   Result   <>   nil   then
                   Exit;
           end;
       end;
 end;

****************************************************************************

 49 指定Filter   Builder打开/保存过滤文件的默认路径
解决：
uses  
      ...,   cxFilterControlDialog;  
   
procedure   TForm.GridView1FilterControlDialogShow(  
      Sender:   TObject);  
begin  
      TfmFilterControlDialog(Sender).OpenDialog.InitialDir   :=   'D:/'  
end;