关于动态创建控件及拖动伸缩

2015-07-13 04:36:31 300 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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C++ Qt实战入门：从零构建跨平台桌面应用开发环境与核心机制 C++作为高性能系统编程语言，在桌面应用开发中面临图形界面构建和跨平台适配的挑战。Qt框架通过信号槽机制和对象树模型，为C++提供了成熟的GUI解决方案，实现了事件驱动编程和半自动内存管理。其技术价值在于将C++的底层控制力与现代框架的开发效率结合，支持快速构建工业级桌面、嵌入式及移动端应用。在应用场景上，Qt广泛用于工业软件、汽车中控、医疗设备等对性能和可靠性要求高的领域。本文以Qt 5.15 LTS和MSVC编译器为例，详解环境搭建、核心机制及项目发布流程，帮助开发者掌握C++ Qt开发的关键技能。阅读详情

1、动态创建自定义组件，显示（同时显示8个小黑矩形，跟Delphi的IDE把控件放窗口一样有8个小的黑色方块)---- 动态创建可以实现，但是暂时没想到怎么画这8个小黑块，在哪个事件里实现，或者是在设计组件的时候封装，具体想不好怎么实现
2、动态生成的这些控件可拖动可伸缩

网上资料找了不少，只是还没一个完整的思路来实现上面的功能，所以来请教一下。

...全文

MATLAB App Designer UI元素添加：从静态拖拽到动态编程在图形用户界面（GUI）开发中，UI元素是构建交互功能的基础模块。其原理在于通过视图层定义外观，控制器层（回调函数）定义行为，实现用户与数据的双向交互。这种分离设计提升了代码的可维护性和应用的可扩展性。从技术价值看，灵活的UI管理能显著增强软件的功能完整性与用户体验。在MATLAB App Designer这一集成开发环境中，开发者既可通过可视化拖拽静态添加固定控件，也能在运行时根据逻辑动态生成UI组件，这尤其适用于需要**动态创建**复杂交互或数据可视化界面的工程场景。掌握这两种路径，并结合**网格布局* 阅读详情

dds2014

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EP外星人 2015-07-17

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procedure TResizer.SizerDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  Sizing  := True;
  DownX   := X;
  DownY   := Y;
  HideSizers;
  ResizeControl.Parent.Update;
  ResizeControl.Update;
  OrigSize := ResizeControl.BoundsRect;
  NewSize  := OrigSize;
  DrawSizeRect(NewSize);
end;

procedure DoSwap(DoSwap: boolean; var a, b: integer);
var
  t : integer;
begin
  if DoSwap then begin
     t := a;
     a := b;
     b := t;
  end;
end;

procedure TResizer.SizerUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  if NewSize.Right < NewSize.Left then
     DoSwap(True, NewSize.Right, NewSize.Left);
  if NewSize.Bottom < NewSize.Top then
     DoSwap(True, NewSize.Bottom, NewSize.Top);
     
  Sizing := False;
  DrawSizeRect(NewSize);
  ResizeControl.Invalidate;
  ResizeControl.BoundsRect := NewSize;
  ShowSizers;
  if Assigned(OnSized) then OnSized(Self);
end;

procedure TResizer.SizerMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
  if Sizing then begin
     DrawSizeRect(NewSize);

     if AllowSize then begin
        Calc_Size_Rect((Sender as TSizer).Tag, X - DownX, Y - DownY);
        DoSizingEvent;
     end;

     DrawSizeRect(NewSize);
     if HotTrack then ResizeControl.BoundsRect := NewSize;
  end;
end;

procedure TResizer.DoSizingEvent;
var
  tmpWid, tmpHgt  : integer;
begin
  tmpWid := NewSize.Right - NewSize.Left;
  tmpHgt := NewSize.Bottom - NewSize.Top;
  if Assigned(OnSizing) then
     OnSizing(Self, NewSize.Left, NewSize.Top, tmpWid, tmpHgt);
  NewSize.Right  := NewSize.Left + tmpWid;
  NewSize.Bottom := NewSize.Top + tmpHgt;
end;

procedure GetNonClientOffset(h: THandle; var nx, ny: integer);
var
  p : TPoint;
  R : TRect;
begin
  p := Point(0, 0);
  Windows.ClientToScreen(h, p);
  Windows.GetWindowRect(h, R);
  nx := p.x - R.Left;
  ny := p.y - R.Top;
end;

procedure TResizer.DrawSizeRect(Rect: TRect);
var
  h        : THandle;
  dc       : THandle;
  c        : TCanvas;
  nx, ny   : integer;
  OldPen   : TPen;
  OldBrush : TBrush;
begin
  if HotTrack then exit;

  h  := (ResizeControl.Parent as TWinControl).Handle;
  GetNonClientOffset(h, nx, ny);
  dc := GetWindowDC(h);
  try
     c := TCanvas.Create;
     c.Handle := dc;

     OldPen := TPen.Create;
     OldPen.Assign(c.Pen);
     OldBrush := TBrush.Create;
     OldBrush.Assign(c.Brush);

     c.Pen.Width := 2;
     c.Pen.Mode  := pmXOR;
     c.Pen.Color := clWhite;
     c.Brush.Style := bsClear;
     c.Rectangle(Rect.Left + nx, Rect.Top + ny, Rect.Right + nx, Rect.Bottom + ny);

     c.Pen.Assign(OldPen);
     OldPen.Free;
     c.Brush.Assign(OldBrush);
     OldBrush.Free;

     c.Handle := 0;
     c.Free;
  finally
     ReleaseDC(h, dc);
  end;
end;

procedure TResizer.Calc_Size_Rect(SizerNum, dx, dy: integer);
begin
  dx := (dx div GridX) * GridX;
  dy := (dy div GridY) * GridY;

  case SizerNum of
     0, 1, 2 : NewSize.Top    := OrigSize.Top + dy;
     5, 6, 7 : NewSize.Bottom := OrigSize.Bottom + dy;
  end;

  case SizerNum of
     0, 3, 5 : NewSize.Left   := OrigSize.Left + dx;
     2, 4, 7 : NewSize.Right  := OrigSize.Right + dx;
  end;

  if KeepInParent then Constrain_Size;
end;

procedure TResizer.MoverDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  CurMover := Sender as TMover;
  FControl := CurMover.Buddy;
  Assert(FControl<>nil);
  FControl.BringToFront;
  CurMover.BringToFront;

  Moving := True;
  DownX := X;
  DownY := Y;
  HideSizers;
  ResizeControl.Parent.Update;
  ResizeControl.Update;
  OrigSize := ResizeControl.BoundsRect;
  NewSize  := OrigSize;
  DrawSizeRect(NewSize);
end;

procedure TResizer.MoverUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  Moving := False;
  ResizeControl.BoundsRect := NewSize;
  CurMover.Invalidate;
  ResizeControl.Refresh;
  DrawSizeRect(NewSize);
  ShowSizers;
  if Assigned(OnMoved) then OnMoved(Self);
end;

procedure TResizer.Calc_Move_Rect(dx, dy: integer);
begin
  NewSize := OrigSize;
  dx := (dx div GridX) * GridX;
  dy := (dy div GridY) * GridY;
  OffsetRect(NewSize, dx, dy);
  if KeepInParent then Constrain_Move;
end;

procedure TResizer.DoMovingEvent;
var
  tmpWid, tmpHgt : integer;
begin
  tmpWid := NewSize.Right - NewSize.Left;
  tmpHgt := NewSize.Bottom - NewSize.Top;
  if Assigned(OnMoving) then
     OnMoving(Self, NewSize.Left, NewSize.Top);
  NewSize.Right := NewSize.Left + tmpWid;
  NewSize.Bottom := NewSize.Top + tmpHgt;
end;

procedure TResizer.MoverMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
var
  dx, dy: integer;
begin
  if Moving then begin
     DrawSizeRect(NewSize);

     if AllowMove then begin
        dx := X - DownX;
        dy := Y - DownY;
        Calc_Move_Rect(dx, dy);
        DoMovingEvent;
     end;

     DrawSizeRect(NewSize);
     if HotTrack then ResizeControl.BoundsRect := NewSize;
  end;
end;

procedure TResizer.Constrain_Size;
var
  p : TWinControl;
begin
  p := ResizeControl.Parent;

  with NewSize do begin
     if Left < 0 then Left := 0;
     if Top < 0 then Top := 0;
     if Right > p.ClientWidth then Right := p.ClientWidth;
     if Bottom > p.ClientHeight then Bottom := p.ClientHeight;

     if Right < Left + GridX then Right := Left + GridX;
     if Bottom < Top + GridY then Bottom := Top + GridY;
  end;
end;

procedure TResizer.Constrain_Move;
begin
  if NewSize.Left < 0 then
     OffsetRect(NewSize, -NewSize.Left, 0);

  if NewSize.Top < 0 then
     OffsetRect(NewSize, 0, -NewSize.Top);

  if NewSize.Right > ResizeControl.Parent.ClientWidth then
     OffsetRect(NewSize, ResizeControl.Parent.ClientWidth - NewSize.Right, 0);

  if NewSize.Bottom > ResizeControl.Parent.ClientHeight then
     OffsetRect(NewSize, 0, ResizeControl.Parent.ClientHeight - NewSize.Bottom);
end;

procedure TResizer.MoverKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
begin
  if Active then begin
     case Key of
        VK_LEFT  : DoSizeMove(Key, Shift, -GridX,  0);
        VK_RIGHT : DoSizeMove(Key, Shift,  GridX,  0);
        VK_UP    : DoSizeMove(Key, Shift,  0, -GridY);
        VK_DOWN  : DoSizeMove(Key, Shift,  0,  GridY);
     end;
  end;
end;

procedure TResizer.DoSizeMove(var Key: Word; Shift: TShiftState; dx, dy: integer);
begin
  if (ssCtrl in Shift) or (ssShift in Shift) then begin
     Key := 0;

     NewSize := ResizeControl.BoundsRect;

     if (ssCtrl in Shift) and AllowMove then begin
        OffsetRect(NewSize, dx, dy);
        if KeepInParent then Constrain_Move;
        DoMovingEvent;
     end;

     if (ssShift in Shift) and AllowSize then begin
        NewSize.Right  := NewSize.Right + dx;
        NewSize.Bottom := NewSize.Bottom + dy;
        if KeepInParent then Constrain_Size;
        DoSizingEvent;
     end;

     ResizeControl.BoundsRect := NewSize;
     ShowSizers;
  end;
end;

function TResizer.FindMoverByBuddy(c: TControl): TMover;
var
  i : integer;
begin
  Result := nil;
  for i := 0 to GroupMovers.Count-1 do
     if TMover(GroupMovers[i]).Buddy = c then
        Result := GroupMovers[i];
  Assert(Result <> nil);
end;

end.

这个控件装上去，就能设置控件在程序运行时随意拖动，就象设计时一样，边上还有四个小点 1.在label的OnMouseDown中写label1.BeginDrag(false); 2.在TForm1 OnDragOver中写if Source is TLabel Accept=true; 3.在Form1的OnDrawDrop中写 Label1.left=x; Label1.top=y; 如果是Panel或Button,可以用Perform() void __fastcall TForm1::Panel1MouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift, int X, int Y) { int SC_DragMove=0xF012; ReleaseCapture(); Panel1->Perform(WM_SYSCOMMAND,SC_DragMove,0); }

EP外星人 2015-07-17

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大富翁论坛以前的帖子： interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, ExtCtrls; const GRIDDEFAULT = 4; type TResizer = class; TMover = class; TMovingEvent = procedure(Sender: TResizer; var NewLeft, NewTop: integer) of object; TSizingEvent = procedure(Sender: TResizer; var NewLeft, NewTop, NewWidth, NewHeight: integer) of object; TResizer = class(TComponent) protected FActive : boolean; FControl : TControl; Sizers : TList; GroupMovers : TList; FGroup : TWinControl; FGridX : integer; FGridY : integer; FOnSized : TNotifyEvent; FOnSizing : TSizingEvent; FOnMoved : TNotifyEvent; FOnMoving : TMovingEvent; Sizing : boolean; Moving : boolean; OrigSize : TRect; NewSize : TRect; DownX : integer; DownY : integer; FAllowSize : boolean; FAllowMove : boolean; FKeepIn : boolean; FHotTrack : boolean; OneMover : TMover; CurMover : TMover; procedure Notification(AComponent: TComponent; Operation: TOperation); override; procedure SetActive(b: boolean); procedure SetControl(c: TControl); procedure SetGroup(p: TWinControl); procedure CreateSizers; procedure CheckSizers; procedure ShowSizers; procedure HideSizers; procedure SizerDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure SizerUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure SizerMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); procedure MoverDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure MoverUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer); procedure MoverMove(Sender: TObject; Shift: TShiftState; X, Y: Integer); procedure DrawSizeRect(Rect: TRect); procedure Calc_Size_Rect(SizerNum, dx, dy: integer); procedure DoSizingEvent; procedure Calc_Move_Rect(dx, dy: integer); procedure DoMovingEvent; procedure Constrain_Size; procedure Constrain_Move; procedure MoverKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState); procedure DoSizeMove(var Key: Word; Shift: TShiftState; dx, dy: integer); procedure CreateGroupMovers; procedure CreateOneMover(m: TMover; c: TControl); function FindMoverByBuddy(c: TControl): TMover; public constructor Create(AOwner: TComponent); override; destructor Destroy; override; published property Active: boolean read FActive write SetActive default True; property ResizeControl: TControl read FControl write SetControl; property ResizeGroup: TWinControl read FGroup write SetGroup; property GridX: integer read FGridX write FGridX default GRIDDEFAULT; property GridY: integer read FGridY write FGridY default GRIDDEFAULT; property OnSized: TNotifyEvent read FOnSized write FOnSized; property OnSizing: TSizingEvent read FOnSizing write FOnSizing; property OnMoved: TNotifyEvent read FOnMoved write FOnMoved; property OnMoving: TMovingEvent read FOnMoving write FOnMoving; property AllowSize: boolean read FAllowSize write FAllowSize default True; property AllowMove: boolean read FAllowMove write FAllowMove default True; property KeepInParent: boolean read FKeepIn write FKeepIn default True; property HotTrack: boolean read FHotTrack write FHotTrack; end; TInvisWin = class(TPanel) // This could also derive from TPanel protected procedure WndProc(var Message: TMessage); override; procedure CreateParams(var Params: TCreateParams); override; procedure WMDLGCode(var Message: TMessage); message WM_GETDLGCODE; public property OnKeyDown; end; TMover = class(TInvisWin) public Buddy : TControl; procedure Show; end; procedure Register; implementation const SIZE = 6; HALFSIZE = SIZE div 2; type TSizer = class(TPanel) end; procedure Register; begin RegisterComponents('Samples', [TResizer]); end; // ***************************************************************** // TInvisWin procedure TInvisWin.WndProc(var Message: TMessage); var ps : TPaintStruct; begin case Message.Msg of WM_ERASEBKGND: Message.Result := 1; WM_PAINT: begin BeginPaint(Handle, ps); EndPaint(Handle, ps); Message.Result := 1; end; else inherited WndProc(Message); end; end; procedure TInvisWin.CreateParams(var Params: TCreateParams); begin inherited; Params.ExStyle := Params.ExStyle or WS_EX_TRANSPARENT; end; procedure TInvisWin.WMDLGCode(var Message: TMessage); begin Message.Result := DLGC_WANTARROWS or DLGC_WANTALLKEYS; end; // ***************************************************************** // TMover procedure TMover.Show; begin Assert(Buddy <> nil); BoundsRect := Buddy.BoundsRect; Parent := Buddy.Parent; Visible := True; BringToFront; end; // ***************************************************************** // TResizer constructor TResizer.Create(AOwner: TComponent); begin inherited; FActive := True; FKeepIn := True; FGridX := GRIDDEFAULT; FGridY := GRIDDEFAULT; FAllowSize := True; FAllowMove := True; GroupMovers := TList.Create; Sizers := TList.Create; OneMover := TMover.Create(Self); CreateOneMover(OneMover, nil); CreateSizers; end; destructor TResizer.Destroy; begin GroupMovers.Free; Sizers.Free; Sizers := nil; inherited; end; procedure TResizer.Notification(AComponent: TComponent; Operation: TOperation); begin inherited; if csDestroying in ComponentState then exit; if (AComponent = ResizeControl) and (Operation = opRemove) then ResizeControl := nil; end; procedure TResizer.SetActive(b: boolean); begin if b<>FActive then begin FActive := b; CheckSizers; end; end; procedure TResizer.SetControl(c: TControl); begin if c <> FControl then begin if c<>nil then begin if ResizeGroup<>nil then begin Assert(c.Parent = ResizeGroup, 'ResizeControl is not in ResizeGroup!'); CurMover := FindMoverByBuddy(c); end else begin CurMover := OneMover; CurMover.Buddy := c; end; CurMover.Show; end; FControl := c; CheckSizers; end; end; procedure TResizer.SetGroup(p: TWinControl); begin if p <> FGroup then begin FGroup := p; CreateGroupMovers; end; end; procedure TResizer.CreateGroupMovers; var i : integer; m : TMover; c : TControl; begin if csDesigning in ComponentState then exit; // Clear out the old Movers for i := 0 to GroupMovers.Count-1 do TObject(GroupMovers[i]).Free; GroupMovers.Clear; if ResizeGroup <> nil then begin for i := 0 to ResizeGroup.ControlCount-1 do begin c := ResizeGroup.Controls[i]; if (c is TMover) or (c is TSizer) then continue; m := TMover.Create(Self); CreateOneMover(m, c); GroupMovers.Add(m); m.Show; end; end; end; procedure TResizer.CreateSizers; var i : integer; p : TSizer; begin if csDesigning in ComponentState then exit; for i := 0 to 7 do begin p := TSizer.Create(Self); Sizers.Add(p); p.BevelOuter := bvNone; p.Width := SIZE; p.Height := SIZE; p.Color := clBlack; p.Caption := ''; p.Tag := i; p.OnMouseDown := SizerDown; p.OnMouseUp := SizerUp; p.OnMouseMove := SizerMove; p.TabStop := False; case i of 0, 7 : p.Cursor := crSizeNWSE; 2, 5 : p.Cursor := crSizeNESW; 1, 6 : p.Cursor := crSizeNS; 3, 4 : p.Cursor := crSizeWE; end; end; end; procedure TResizer.CreateOneMover(m: TMover; c: TControl); begin m.OnMouseDown := MoverDown; m.OnMouseUp := MoverUp; m.OnMouseMove := MoverMove; m.TabStop := True; m.OnKeyDown := MoverKeyDown; m.Buddy := c; end; procedure TResizer.CheckSizers; begin if (ResizeControl<>nil) and Active and (not (csDesigning in ComponentState)) then ShowSizers else HideSizers; end; procedure TResizer.ShowSizers; var i : integer; p : TPanel; c : TControl; begin c := ResizeControl; Assert(c <> nil); for i := 0 to 7 do begin p := TPanel(Sizers[i]); case i of 0, 1, 2 : p.Top := c.Top - HALFSIZE; 3, 4 : p.Top := c.Top + c.Height div 2 - HALFSIZE; 5, 6, 7 : p.Top := c.Top + c.Height - HALFSIZE; end; case i of 0, 3, 5 : p.Left := c.Left - HALFSIZE; 1, 6 : p.Left := c.Left + c.Width div 2 - HALFSIZE; 2, 4, 7 : p.Left := c.Left + c.Width - HALFSIZE; end; end; Assert(CurMover<>nil); CurMover.Show; for i := 0 to Sizers.Count-1 do begin p := TPanel(Sizers[i]); p.Parent := c.Parent; p.Visible := True; p.BringToFront; end; if CurMover.HandleAllocated and CurMover.CanFocus then CurMover.SetFocus; end; procedure TResizer.HideSizers; var i : integer; p : TPanel; begin for i := 0 to Sizers.Count-1 do begin p := TPanel(Sizers[i]); p.Visible := False; p.Update; end; OneMover.Visible := False; end; [/code]

dds2014 2015-07-17

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谢谢楼上的朋友，先结贴，我慢慢再研究

dds2014 2015-07-16

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引用 5 楼 wk_knife 的回复:

以俺近20年的delphi的见识，这个功能有人实现过，并且有源码。好好搜吧。

这几天都在网上查找和自己测试中，源码没找到，相关的思路有一些，测试了，对系统自带的控件可以实现，但是我自己开发的控件就不行，原因查找中

dds2014 2015-07-15

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这2天测试了一下，自己开发的控件虽然在mousedown和mousemove在加了代码，但是控件还是不会自动伸缩，是不是自己开发的的控件也需要把mousemove和mousedown这些事件override？

EP外星人 2015-07-15

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以俺近20年的delphi的见识，这个功能有人实现过，并且有源码。好好搜吧。

lsh341999 2015-07-14

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VCL版本 http://bbs.csdn.net/topics/390630985 状况：完结使用情况：已在平台上开发了几个系统了平台：WINDOWS【免编译】 FMX 版本 http://bbs.2ccc.com/topic.asp?topicid=478231 状况：未完结，原因：除了PAX脚本几本没有什么第三方支持，什么都要自己写、开发进度很慢，很慢。现在卡在IDE的代码编辑器上，亮显功能已经写1个月了还没完成。平台：WINDOWS，安卓，IOS【没试过，理论上应该可以】上述都是三层框架。平台业务程序模块都是存储在服务端，如果FMX版能完成，跨平台真的可以做到免编译了。

lyhoo163 2015-07-13

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此事要自己慢慢地搞啊！

缘中人 2015-07-13

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有个Resizer可以实现。 http://bbs.csdn.net/topics/70270932

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