如何让TPanel透明

你把窗体上的Panel的颜色改为clBlack，然后你再把窗体的TransparentColor
设为True,然后再把TransparentColorValue改为clBlack，运行试试是不是这
个意思。

说什么?具体点:是隐藏还是xp风格的窗体,隐藏的话可以调用windows API函数, xp风格就象楼上说的那样改变颜色,隐藏是可以在在状态栏,任务管理器全部隐藏.

给你一个！
还有其他功能，自己看吧
在自动调整大小时，有些问题
==============================================================================={
David 修改的来自网络的控件。
可以实现：自动调整panel里的控件的位置和大小，添加背景
在自动调整大小时，有些问题，如果修改好，请给我一份
[email protected]}
unit AutoPnl;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls;type  TPlacement = record
    Left, Top, Width, Height: Integer;
  end;
  TFooClass = class(TControl); { needed to get at protected }{ font property }  PIntArray = ^TRectArray;
  TRectArray = array[0..4096] of TPlacement;  TAutoPanel = class(TCustomPanel)
  private
    { Private declarations }
    FWallpaper: TPicture;
    FTransparent: Boolean;
    procedure SetTransparent(value: Boolean);
    procedure WallpaperChanged(Sender: TObject);
    procedure SetWallpaper(Value: TPicture);
  protected
    { Protected declarations }
   pWidth :Integer;
   pHeight:Integer;
   FAutoChildPosLeft : Boolean;
   FAutoChildPosTop : Boolean;
   FAutoChildWidth : Boolean;
   FAutoChildHeight : Boolean;
   PCtrlsCoordArr:PIntArray;
   procedure Resize; override;
   procedure Paint; override;
  // procedure CreateParams(var Params: TCreateParams); override;
  // procedure SetParent(AParent: TWinControl); override;
   procedure DrawParentImage(Control: TControl; Dest: TCanvas);
  public
    { Public declarations }
    constructor Create(AOwner: TComponent); override;
    destructor Destroy; override;
    procedure Loaded; override;
//    procedure SetBounds(ALeft, ATop, AWidth, AHeight: Integer); override;  published
    property AutoChildPosLeft : Boolean read FAutoChildPosLeft write FAutoChildPosLeft default False;
    property AutoChildPosTop : Boolean read FAutoChildPosTop write FAutoChildPosTop default False;
    property AutoChildWidth : Boolean  read FAutoChildWidth write FAutoChildWidth default False;
    property AutoChildHeight : Boolean read FAutoChildHeight write FAutoChildHeight default False;    property Align;
    property Alignment;
    property BevelInner;
    property BevelOuter;
    property BevelWidth;
    property BorderWidth;
    property BorderStyle;
    property DragCursor;
    property DragMode;
    property Enabled;
    property Caption;
    property Color;
    property Ctl3D;
    property Font;
    property Locked;
    property ParentColor;
    property ParentCtl3D;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
  //  property ParentShowHint default False;
    property ShowHint default true;
    property TabOrder;
    property TabStop;
    property Wallpaper: TPicture read FWallpaper write SetWallpaper;
    property Transparent: Boolean read FTransparent write SetTransparent default false;
    property Visible;    property OnClick;
    property OnDblClick;
    property OnDragDrop;
    property OnDragOver;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
    property OnResize;
    property OnStartDrag;{$IFDEF VER120} {Borland Delphi 4.0 }
    property Anchors;
    property AutoSize;
    property BiDiMode;
    property Constraints;
    property UseDockManager default True;
    property DockSite;
    property DragKind;
    property FullRepaint;
    property ParentBiDiMode;    property OnCanResize;
    property OnConstrainedResize;
    property OnDockDrop;
    property OnDockOver;
    property OnEndDock;
    property OnGetSiteInfo;
    property OnStartDock;
    property OnUnDock;
{$ENDIF}    { Published declarations }
  end;procedure Register;implementation procedure TAutoPanel.DrawParentImage(Control: TControl; Dest: TCanvas);
var
  SaveIndex: Integer;
  DC: HDC;
  Position: TPoint;
begin
  with Control do
  begin
    if Parent = nil then
      Exit;
    DC := Dest.Handle;
    SaveIndex := SaveDC(DC);
    {$IFDEF DFS_COMPILER_2}
    GetViewportOrgEx(DC, @Position);
    {$ELSE}
    GetViewportOrgEx(DC, Position);
    {$ENDIF}
    SetViewportOrgEx(DC, Position.X - Left, Position.Y - Top, nil);
    IntersectClipRect(DC, 0, 0, Parent.ClientWidth, Parent.ClientHeight);
    Parent.Perform(WM_ERASEBKGND, DC, 0);
    Parent.Perform(WM_PAINT, DC, 0);
    RestoreDC(DC, SaveIndex);
  end;
end;constructor TAutoPanel.Create(AOwner: TComponent);
begin
inherited;
FAutoChildPosLeft := False;
FAutoChildPosTop := False;
FAutoChildWidth := False;
FAutoChildHeight := False;
Caption:='';
pWidth := -1;
pHeight := -1;
PCtrlsCoordArr := nil;
FWallpaper := TPicture.Create;
FWallpaper.OnChange := WallpaperChanged;
ParentShowHint := False;
ShowHint := True;
// inherited Align := alTop;
end;
destructor TAutoPanel.Destroy;
begin
FreeMem(PCtrlsCoordArr);
FWallpaper.OnChange := nil;
FWallpaper.Free;
FWallpaper := nil;
inherited;
end;

procedure TAutoPanel.Loaded;
var i:Integer;
begin
  inherited Loaded;
  if (csDesigning in ComponentState) then Exit;  if (pWidth = -1) and (pHeight = -1) then begin
   GetMem(PCtrlsCoordArr, ControlCount * sizeof(TRect));
   for  i := 0 to ControlCount - 1 do begin
      PCtrlsCoordArr[i].Left := Controls[i].Left;
      PCtrlsCoordArr[i].Top := Controls[i].Top;
      PCtrlsCoordArr[i].Width := Controls[i].Width;
      PCtrlsCoordArr[i].Height := Controls[i].Height;
   end;
   pWidth := Width;
   pHeight := Height;
  end;
end;procedure TAutoPanel.Resize;
var
I:Integer;
// Ph:integer;
begin
inherited;
{
TFooClass(Controls[i]).Font.Size :=
(NewFormWidth div OldFormWidth) *
TFooClass(Controls[i]).Font.Size;
}
if (csDesigning in ComponentState) then Exit;
try  if (AutoChildPosLeft = false) and (AutoChildWidth = false) and
      (AutoChildPosTop = false) and (AutoChildHeight = false) then Exit;  for  i := 0 to ControlCount - 1 do begin
    if(AutoChildPosLeft = true) then
     if (AutoChildWidth = true) then begin
      Controls[i].Left := MulDiv (PCtrlsCoordArr[i].Left,Width,pWidth);
      Controls[i].Width :=  MulDiv (PCtrlsCoordArr[i].Width,Width,pWidth);     end
     else
       Controls[i].Left := Round(
        PCtrlsCoordArr[i].Left * Width / pWidth  +
        ((PCtrlsCoordArr[i].Width) * Width / pWidth -
        (PCtrlsCoordArr[i].Width))/2
        );    if(AutoChildPosTop = true) then
     if (AutoChildHeight = true) then begin
      Controls[i].Top := MulDiv (PCtrlsCoordArr[i].Top,Height,pHeight);
      Controls[i].Height := MulDiv (PCtrlsCoordArr[i].Height,Height,pHeight);
      //TFooClass(Controls[i]).Font.Size:= Round((Height/pHeight)*TFooClass(Controls[i]).Font.Size);
     end
     else       Controls[i].Top := Round(
        PCtrlsCoordArr[i].Top * Height / pHeight +
        ((PCtrlsCoordArr[i].Height)  * Height / pHeight - (PCtrlsCoordArr[i].Height))/2 );  end;
finally
end;
end;//=======
procedure TAutoPanel.WallpaperChanged(Sender: TObject);
begin
  Invalidate;
end;procedure TAutoPanel.SetWallpaper(Value: TPicture);
begin
  FWallpaper.Assign(Value);
end;procedure TAutoPanel.Paint;
var
  XCnt, YCnt, X, Y: Integer;
  BevelSize, SaveIndex: Integer;
  Rect: TRect;
  bitmap:tbitmap;
begin
  inherited Paint;
  if (FWallpaper.Graphic = nil) and FTransparent then
   begin
   // if not (csDesigning in ComponentState) then
   //  exit;
     Bitmap := TBitmap.Create;
    try
      Bitmap.Height := ClientRect.Bottom;
      Bitmap.Width := ClientRect.Right;
      DrawParentImage(Self, Bitmap.Canvas);
      canvas.CopyRect(ClientRect, Bitmap.canvas, ClientRect);
    finally
      Bitmap.free;
     end;
   end
   else
   begin
   if (FWallpaper.Graphic <> nil) and (FWallpaper.Width > 0) and
      (FWallpaper.Height > 0) then
    begin
      Rect := ClientRect;
      BevelSize := BorderWidth;
      if BevelOuter <> bvNone then Inc(BevelSize, BevelWidth);
      if BevelInner <> bvNone then Inc(BevelSize, BevelWidth);
      InflateRect(Rect, -BevelSize, -BevelSize);
      SaveIndex := SaveDC(Canvas.Handle);
      try
        IntersectClipRect(Canvas.Handle, Rect.Left, Rect.Top,
                Rect.Right -Rect.Left +1,
                Rect.Bottom-Rect.Top  +1 );
          XCnt := (ClientWidth - 2 * BevelSize) div FWallpaper.Width;
          YCnt := (ClientHeight - 2 * BevelSize) div FWallpaper.Height;
          for X := 0 to XCnt do
            for Y := 0 to YCnt do
              Canvas.Draw(Rect.Left + X * FWallpaper.Width,
                Rect.Top + Y * FWallpaper.Height, FWallpaper.Graphic);
      finally
        RestoreDC(Canvas.Handle, SaveIndex);
      end;
    end;
    end;
end;//=======//透明
procedure TAutoPanel.SetTransparent(value: boolean);
begin
  if ftransparent <> value then
  begin
    ftransparent := value;
    invalidate;
  end;
end;{procedure TAutoPanel.WMEraseBkgnd(var Msg: TMessage);
begin
  if ftransparent then msg.result := 1
  else inherited;
end;procedure TAutoPanel.CreateParams(var Params: TCreateParams);
begin
  inherited CreateParams(Params);
  params.exstyle := params.exstyle or WS_EX_TRANSPARENT;
end;procedure TAutoPanel.SetParent(AParent: TWinControl);
begin
  inherited setparent(aparent);
  if (aparent <> nil) and aparent.HandleAllocated
    and (GetWindowLong(aparent.handle, GWL_STYLE) and WS_CLIPCHILDREN <> 0) then
  setwindowlong(aparent.handle, GWL_STYLE,
                          GetWindowLong(aparent.handle, GWL_STYLE)
                          and not WS_CLIPCHILDREN);
end;procedure TAutoPanel.SetBounds(ALeft, ATop, AWidth, AHeight: Integer);
begin
  invalidate;
  inherited setbounds(aleft, atop, awidth, aheight);
end;}////procedure Register;
begin
  RegisterComponents('Xac', [TAutoPanel]);
end;end.

有个现成的控件：TCHPanel,可以设置透明属性。

TCHPanel控件不能用呀，设置之后，还是会挡在别的控件前面。

调试易

如何让TPanel透明

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