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;