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  • Query1AfterScroll 与 DataSource1DataChange 区别

    这个事件 对每个字段都处理,在窗体退出时,因关闭了数据集,所以这个事件也要执行一次。这样就会造成,内存地址错误。

    procedure TFrmYaoKYPCKBL.DataSource1DataChange(Sender: TObject; Field: TField);
    begin
    inherited;
    ShowMessage('ds');

    if Query1YiJSZ.Value = 1 then
    begin
    TB_Save.Enabled := False;
    TB_ShangZ.Enabled := False;
    TB_Delete.Enabled := False;
    btnSave.Enabled := False;
    btnShangZ.Enabled := False;

    DBComboBox2.Enabled := False;
    DBEdit3.Enabled := False;

    DBGrideh1.readonly := True;
    btnErase.Enabled := False;
    end
    else
    begin
    TB_Save.Enabled := True;
    TB_ShangZ.Enabled := True;
    TB_Delete.Enabled := True;
    btnSave.Enabled := True;
    if not _ChuKMXModified then
    begin
    btnShangZ.Enabled := True;
    end
    else
    begin
    btnShangZ.Enabled := False;
    end;

    end;

    而表的滚动事件,则不会在窗体关闭时执行。只是有数据时才执行。  所处程序除非必要检查特定字段,不要在datasource事件内写东西。

    procedure TFrmYaoKYPCKBL.Query1AfterScroll(DataSet: TDataSet);
    begin
    inherited;

    if Query1YiJSZ.Value = 1 then
    begin
    TB_Save.Enabled := False;
    TB_ShangZ.Enabled := False;
    TB_Delete.Enabled := False;
    btnSave.Enabled := False;
    btnShangZ.Enabled := False;

    DBComboBox2.Enabled := False;
    DBEdit3.Enabled := False;

    DBGrideh1.readonly := True;
    btnErase.Enabled := False;
    end
    else
    begin
    TB_Save.Enabled := True;
    TB_ShangZ.Enabled := True;
    TB_Delete.Enabled := True;
    btnSave.Enabled := True;
    if not _ChuKMXModified then
    begin
    btnShangZ.Enabled := True;
    end
    else
    begin
    btnShangZ.Enabled := False;
    end;

    DBComboBox2.Enabled := False;
    DBEdit3.Enabled := True;

    DBGrideh1.readonly := False;
    btnErase.Enabled := True;
    end;
    end;

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  • 原文地址:https://www.cnblogs.com/maweiwei/p/7473786.html
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