CXGrid的使用技巧

排序后移到第一行

可以设置DataController.Options.FocusTopRowAfterSorting := True，也可以使用如下的代码：

uses
cxCustomData;

procedure TYour_Form.Your_ViewDataControllerSortingChanged(Sender: TObject);
begin
TcxCustomDataController(Sender).FocusedRowIndex := 0;
end;

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判断当前行是否第一行或最后一行

可以使用DataController的IsBOF, IsEOF方法，或者：
<AView>.Controller.Controller.FocusedRow.IsFirst
<AView>.Controller.Controller.FocusedRow.IsLast

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根据指定值查找记录

DataController提供了好几个方法来得到指定值对应的RecordIndex
对于Bound View可以使用FindRecordIndexByKeyValue方法

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编辑和显示Blob字段

该字段的Properties设置为BlobEdit，并将BlobPaintStyle 属性设为 bpsText

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得到可见行数

<View>.ViewInfo.VisibleRecordCount

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保存后的行设置为当前行

const
CM_SETFOCUSEDRECORD = WM_USER + 1002;

type
TForm1 = class(TForm)
cxGrid1DBTableView1: TcxGridDBTableView;
cxGrid1Level1: TcxGridLevel;
cxGrid1: TcxGrid;
dxMemData1: TdxMemData;
dxMemData1Field1: TStringField;
dxMemData1Field2: TIntegerField;
DataSource1: TDataSource;
cxGrid1DBTableView1RecId: TcxGridDBColumn;
cxGrid1DBTableView1Field1: TcxGridDBColumn;
cxGrid1DBTableView1Field2: TcxGridDBColumn;
Timer1: TTimer;
CheckBox1: TCheckBox;
procedure Timer1Timer(Sender: TObject);
procedure dxMemData1AfterPost(DataSet: TDataSet);
procedure CheckBox1Click(Sender: TObject);
private
procedure CMSetFocusedRecord(var Msg: TMessage); message CM_SETFOCUSEDRECORD;
public
{ Public declarations }
end;

var
Form1: TForm1;
FocusedIdx: Integer;

implementation

{$R *.dfm}

procedure TForm1.Timer1Timer(Sender: TObject);
begin
dxMemData1.AppendRecord(['', IntToStr(Random(1000)), Random(1000)]);
end;

procedure TForm1.dxMemData1AfterPost(DataSet: TDataSet);
begin
PostMessage(Handle, CM_SETFOCUSEDRECORD, Integer(cxGrid1DBTableView1), MakeLParam(cxGrid1DBTableView1.Controller.FocusedRowIndex, cxGrid1DBTableView1.Controller.TopRowIndex));
end;

procedure TForm1.CMSetFocusedRecord(var Msg: TMessage);
begin
TcxGridDBTableView(msg.WParam).Controller.FocusedRowIndex := Msg.LParamLo;
TcxGridDBTableView(msg.WParam).Controller.TopRowIndex := Msg.LParamHi;
end;

procedure TForm1.CheckBox1Click(Sender: TObject);
begin
Timer1.Enabled := TCheckBox(Sender).Checked;
end;

end.

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删除记录并获得焦点

procedure TForm1.BtnDeleteClick(Sender: TObject);
var
FocusedRow, TopRow: Integer;
View: TcxGridTableView;
DataController: TcxGridDataController;
begin
View := cxGrid1.FocusedView as TcxGridTableView;
DataController := View.DataController;

// Remember the top row (the vertical scrollbar position)
TopRow := View.Controller.TopRowIndex;
// Remember the focused row(!) index
FocusedRow := DataController.FocusedRowIndex;

DataController.DeleteFocused;

// After deletion the same row must be focused,
// although it will correspond to a different data record
DataController.FocusedRowIndex := FocusedRow;
// Restore the top row
View.Controller.TopRowIndex := TopRow;
end;
 

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