} } }

    如今应用控件, 更喜好持续

    添加时间:2013-7-25 点击量:


    以前写代码, 老是把主单位弄得满满当当; 如今更喜好把控件斗劲自力的功能写成一个单位, 改写属性、重载办法...哪怕只有一点点和默认不合, 也喜好自力出来.



    方才用到 TListBox, 须要能拖动元素、双击删除.



    unit ListBox2;

    interface

    uses
    System.Classes, Vcl.Controls, Vcl.StdCtrls, System.Types;

    type
    TListBox2 = class(TCustomListBox)
    protected
    procedure DragOver(Source: TObject; X: Integer; Y: Integer; State: TDragState; var Accept: Boolean); override;
    procedure DblClick; override;
    public
    constructor Create(AOwner: TComponent); override;
    procedure DragDrop(Source: TObject; X: Integer; Y: Integer); override;
    end;

    implementation

    { TListBox2 }

    constructor TListBox2.Create(AOwner: TComponent);
    begin
    inherited;
    DragMode := dmAutomatic;
    end;

    procedure TListBox2.DblClick;
    begin
    inherited;
    Items.Delete(ItemIndex);
    end;

    procedure TListBox2.DragDrop(Source: TObject; X, Y: Integer);
    begin
    inherited;
    Items.Exchange(ItemIndex, ItemAtPos(Point(X,Y), True));
    end;

    procedure TListBox2.DragOver(Source: TObject; X, Y: Integer; State: TDragState; var Accept: Boolean);
    begin
    inherited;
    Accept := True;
    end;

    end.




    测试:



    uses ListBox2;

    procedure TForm1.FormCreate(Sender: TObject);
    begin
    with TListBox2.Create(Self) do begin
    Parent := Self;
    Align := alLeft;
    Items.CommaText := A,B,C,D,E,F,G;
    end;
    end;

    无论对感情还是对生活,“只要甜不要苦”都是任性而孩子气的,因为我们也不完美,我们也会伤害人。正因为我们都不完美,也因为生活从不是事事如意,所以对这些“瑕疵”的收纳才让我们对生活、对他人的爱变得日益真实而具体。—— 汪冰《世界再亏欠你,也要敢于拥抱幸福》
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