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通用查询组件设计(续)
作者:武汉SEO闵涛  文章来源:敏韬网  点击数1837  更新时间:2009/4/23 18:35:32  文章录入:mintao  责任编辑:mintao
FOriginalVariables.Add(TDBVariable.Create(TQuery(FDataSet).Params[i].Name, TQuery(FDataSet).Params[i].Value)); //定义参数数据变量类

  SetFields;//设置字段

end;

 

恢复SQL

procedure TDBFilterDialog.RestoreSQL;

var

  i : Integer;

begin

//恢复SQL语句

  // Disable the controls while we are working

  FDataSet.DisableControls;

  FDataSet.Close;

  // clear the existing SQL and variable declarations

  // restore the original SQL and variables

  SetOrdProp(FDataSet, SQLProp, Integer(FOriginalSQL));

  if FDataSet is TDataSet then

    for i := 0 to FOriginalVariables.Count - 1 do

      TQuery(FDataSet).ParamByName(TDBVariable(FOriginalVariables[i]).VariableName).Value :=

         TDBVariable(FOriginalVariables[i]).VariableValue

  else

    for i := 0 to FOriginalVariables.Count - 1 do

      TQuery(FDataSet).ParamByName(TdBVariable(FOriginalVariables[i]).VariableName).Value :=

         TDBVariable(FOriginalVariables[i]).VariableValue;

  FDataSet.Open;

  SetFields;

  FDataSet.EnableControls;

  FModifiedSQL.Assign(TStrings(GetOrdProp(FDataSet, SQLProp)));

end;

 

保存参数值

procedure TDBFilterDialog.SaveParamValues;

var

  i : Integer;

begin

//保存参数值

   if FDataSet is TDataSet then

    for i := 0 to FOriginalVariables.Count - 1 do

      TDBVariable(FOriginalVariables[i]).VariableValue :=

        TQuery(FDataSet).ParamByName(TDBVariable(FOriginalVariables[i]).VariableName).Value

  else

    for i := 0 to FOriginalVariables.Count - 1 do

      TDBVariable(FOriginalVariables[i]).VariableValue :=

        TQuery(FDataSet).ParamByName(TDBVariable(FOriginalVariables[i]).VariableName).Value;

end;

 

装载过滤对话框

procedure TDBFilterDialog.Loaded;

var

  i : Integer;

begin

  inherited;

  if Assigned(FDataSet) and not (csDesigning in ComponentState) then

  begin

    SetFields;

    OriginalSQL.Assign(TStrings(GetOrdProp(FDataSet, SQLProp)));

    for i := 0 to TQuery(FDataSet).Params.Count - 1 do

        FOriginalVariables.Add(TDBVariable.Create(TQuery(FDataSet).Params[i].Name,

          TQuery(FDataSet).Params[i].Value));

  end;

end;

 

传送消息

procedure TDBFilterDialog.Notification(AComponent: TComponent;

  Operation: TOperation);

begin

  inherited;

  if (AComponent = FDataset) and (Operation = opRemove) then

    FDataset := nil;

end;

 

构造函数

constructor TDBFilterDialog.Create(AOwner: TComponent);

begin

//构造函数

  inherited Create(AOwner);

  FDialog := TMyDBFilterDialog.Create(self);

  FOptions := [fdShowCaseSensitive, fdShowNonMatching];

  FDefaultMatchType := fdMatchStart;

  Caption := SDBFilterCaption;

  FFields := TStringList.Create;

  FOriginalSQL := TStringList.Create;

  FModifiedSQL := TStringList.Create;

  FOriginalVariables := TList.Create;

end;

析构函数

destructor TDBFilterDialog.Destroy;

var

  i : Integer;

begin

  FDialog.Free;

  F

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