Delphi中的窗体移动

2019-11-18 18:54:39

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如果你在开发图形或多媒体应用程序，你可能正在为如何不使用窗体的标题栏而移动窗体发愁。其实只需用鼠标拖动窗体的客户区就可以了。

方法一
　　以下是完成上述功能最普通的方法：在窗体的PRivate声明部分加入以下过程声明：

　　procedure WMNCHitTest(var Msg:TWMNCHitTest);message WM_NCHITTEST;

　　然后在implementation部分加入以下代码：

procedure TForm1{或你定义的Form名}.WMNCHitTest(var Msg:TWMNCHitTest);
begin
DefaultHandler(Msg);
if Msg.Result = HTCLIENT then
Msg.Result:= HTCAPTION;
end;

　　此方法中使当鼠标点击窗体客户区时，令Windows认为被点击的是标题栏。

方法二
　　以下是另一个实现用鼠标移动普通窗体的方法。

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
if (ssLeft in Shift) then begin
ReleaseCapture;
SendMessage(Form1.Handle,WM_SYSCOMMAND,SC_MOVE+1,0);
end;
end;

以上方法不完善之处
　　当把“拖动窗口的过程中显示其内容”的选项取消时，让我们看看会发生什么。这是Windows窗口的一项设置，你可以在“开始菜单-->设置-->文件夹选项-->查看-->高级设置”中找到该属性。在Windows95中，你需要修改注册表。当此属性被设为无效，拖动窗体时窗体会变为一个正方形轮廓线。也许你使用一个不规则窗体，但它仍然会显示轮廓线。
　　当你想要让你的窗体停靠在屏幕的边缘（如：WinAmp，当你拖动窗体进入屏幕顶部某一特定位置时，窗体便紧靠在屏幕顶部），如果你使用以上第二种方法，在鼠标按钮放开前，你将无法处理窗体位置，并无法处理停靠问题。
　　下面我会用简单的方法解决两个问题：
　　第一，无论设置为何，在拖动窗体时都不显示轮廓线；
　　第二，移动窗体时进行位置检测，并在位置适当时停靠在某一特定位置。
　　很多人也许已经解决了这些问题，但是也许下面的代码对你会有帮助。

方法三
　　以下代码可以直接复制到Delphi中，前提是你将Form1存为uMain.pas，Form2存为uDock.pas。用到的事件是：OnMouseDown，OnMouseMove，OnMouseUp，OnShow（Form1）。
　　这是一个根据鼠标的移动移动窗体的方法，包含两个窗体，uMain和uDock（Form1和Form2）。Form2通过Form1打开，并可以停靠在Form1的底部。停靠后，Form2将随Form1一起移动，直到你将Form2移开。

Form1

unit uMain;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;

type
TForm1 = class(TForm)
procedure FormMouseDown(Sender:TObject; Button:TMouseButton;Shift:TShiftState;X,Y: Integer);
procedure FormMouseMove(Sender: TObject; Shift: TShiftState;X,Y: Integer);
procedure FormMouseUp(Sender:TObject;Button:TMouseButton;Shift:TShiftState;X,Y: Integer);
procedure FormShow(Sender: TObject);
private
{ Private declarations }
public
DocktoForm: Boolean;
{ Public declarations }
end;

var
Form1: TForm1;
CanMove, CanMoveX, CanMoveY: Boolean;
OldX, OldY: Integer;
F1X,F1Y,F2X,F2Y: integer;
WorkArea : TRect;

implementation

uses uDock;

{$R *.DFM}

procedure TForm1.FormMouseDown(Sender: TObject; Button: TMouseButton;Shift: TShiftState; X, Y: Integer);
begin
CanMoveX := true;
CanMoveY := true;
CanMove := true;
OldX := X;
OldY := Y;

if DocktoForm then
begin
F1X := Form1.Left;
F1Y := Form1.Top;
F2X := Form2.Left;
F2Y := Form2.Top;
end;

end;

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
if (CanMove) then
begin
if CanMoveX then
Form1.Left := Form1.Left + (X - OldX);

if CanMoveY then
Form1.Top := Form1.Top + (Y - OldY);

//This section latches to the top
if (Form1.Top < WorkArea.Top + 10) and (Form1.Top > WorkArea.Top-10) then
begin
Form1.Top := WorkArea.Top;
if (Y-OldY > 10) or (Y-OldY < -10) then
CanMoveY := true
else
CanMoveY := False;
end;

//This section latches to the left side
if (Form1.Left < WorkArea.Left+10) and (Form1.Left > WoskArea.Left-10) then
begin
Form1.Left := WorkArea.Left;

if (X-OldX > 10) or (X-OldX < -10) then
CanMoveX := true
else
CanMoveX := False;
end;

//This section latches to the right side
if (Form1.Left > WorkArea.Right-Form1.Width-10) and (Form1.Left < WorkArea.Right-Form1.Width+10) then
begin

Form1.Left := WorkArea.Right-Form1.Width;

if (X-OldX > 10) or (X-OldX < -10) then
CanMoveX := true
else
CanMoveX := False;
end;

//This section latches to the TaskBar
if DocktoForm then
begin
if (Form1.Top > WorkArea.Bottom-Form1.Height-Form2.Height-10) and (Form1.Top < WorkArea.Bottom-Form1.Height-Form2.Height+10) then
begin
Form1.Top := WorkArea.Bottom-Form1.Height-Form2.Height;
if (Y-OldY > 10) or (Y-OldY < -10) then
CanMoveY := true
else
CanMoveY := False;
end;
end
else begin
if (Form1.Top > WorkArea.Bottom-Form1.Height-10) and (Form1.Top < WorkArea.Bottom-Form1.Height+10) then
begin
Form1.Top := WorkArea.Bottom-Form1.Height;
if (Y-OldY > 10) or (Y-OldY < -10) then
CanMoveY := true
else
CanMoveY := False;
end;
end;

if DocktoForm then
begin
Form2.Left := Form1.Left - (F1X-F2X);// + (X-OldX);
Form2.Top := Form1.Top+Form1.Height;
exit;
end;

//This section latches playlist in center of Form1
if (Form2.Left > Form1.Left + ((Form1.Width div 2)-(Form2.Width div 2))-10) and (Form2.Left < Form1.Left + ((Form1.Width div 2)-(Form2.Width div 2))+10) and
(Form2.Top > Form1.Top+Form1.Height-10) and (Form2.Top < Form1.Top+Form1.Height+10) then
begin
Form2.Left := Form1.Left + ((Form1.Width div 2)-(Form2.Width div 2));
DocktoForm := True;
F1X := Form1.Left;
F1Y := Form1.Top;
F2X := Form2.Left;
F2Y := Form2.Top;
end;

end;
end;

procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
CanMove := false;
end;

procedure TForm1.FormShow(Sender: TObject);
begin
//Get Work Area Parameters
SystemParametersInfo(SPI_GETWORKAREA, 0, @WorkArea, 0 );
Form2.Show;
end;

end.

Form2

unit uDock;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs;

type
TForm2 = class(TForm)
procedure FormMouseDown(Sender: TObject; Button: TMouseButton;Shift: TShiftState; X, Y: Integer);
procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X,Y: Integer);
procedure FormMouseUp(Sender: TObject; Button: TMouseButton;Shift: TShiftState; X, Y: Integer);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form2: TForm2;
CanMove, CanMoveX, CanMoveY, DocktoForm: Boolean;
OldX, OldY: Integer;

implementation

uses uMain;

{$R *.DFM}

procedure TForm2.FormMouseDown(Sender: TObject; Button: TMouseButton;Shift: TShiftState; X, Y: Integer);
begin
CanMoveX := true;
CanMoveY := true;
CanMove := true;
OldX := X;
OldY := Y;
end;

procedure TForm2.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
begin
if (CanMove) then
begin

if CanMoveX then
Form2.Left := Form2.Left + (X - OldX);
if CanMoveY then
Form2.Top := Form2.Top + (Y - OldY);

//This section latches to the top
if (Form2.Top < WorkArea.Top + 10) and (Form2.Top > WorkArea.Top-10) then
begin
Form2.Top := WorkArea.Top;
if (Y-OldY > 10) or (Y-OldY < -10) then
CanMoveY := true
else
CanMoveY := False;
end;

//This section latches to the left side
if (Form2.Left < WorkArea.Left+10) and (Form2.Left > WorkArea.Left-10) then
begin
Form2.Left := WorkArea.Left;

if (X-OldX > 10) or (X-OldX < -10) then
CanMoveX := true
else
CanMoveX := False;
end;

//This section latches to the right side
if (Form2.Left > WorkArea.Right-Form2.Width-10) and (Form2.Left < WorkArea.Right-Form2.Width+10) then
begin

Form2.Left := WorkArea.Right-Form2.Width;

if (X-OldX > 10) or (X-OldX < -10) then
CanMoveX := true
else
CanMoveX := False;
end;

//This section latches to the TaskBar
if (Form2.Top > WorkArea.Bottom-Form2.Height-10) and (Form2.Top < WorkArea.Bottom-Form2.Height+10) then
begin
Form2.Top := WorkArea.Bottom-Form2.Height;
if (Y-OldY > 10) or (Y-OldY < -10) then
CanMoveY := true
else
CanMoveY := False;
exit;
end;

//This section latches to the Player Bottom
if (Form2.Top > Form1.Top+Form1.Height-10) and (Form2.Top < Form1.Top+Form1.Height+10) and (Form2.Left > Form1.Left-Form2.Width) and (Form2.Left < Form1.Left + Form1.Width) then
begin
Form2.Top := Form1.Top+Form1.Height;
if (Y-OldY > 10) or (Y-OldY < -10) then begin
CanMoveY := true;
Form1.DockToForm := False;
end
else begin
CanMoveY := False;
Form1.DockToForm := True;
end;
end;