WinAPI: SetLayeredWindowAttributes - 设置窗口的透明

WinAPI: SetLayeredWindowAttributes - 设置窗口的透明

这是来宾 Dolby 在 http://www.cnblogs.com/del/archive/2008/03/08/1081295.html#1096814 询问的问题.

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//声明: SetLayeredWindowAttributes(   Hwnd: THandle;  {窗口句柄}   crKey: COLORREF; {透明色}   bAlpha: Byte;    {Alpha 值}   dwFlags: DWORD  {LWA_COLORKEY(=1)表示使用透明色; LWA_ALPHA(=2)表示使用 Alpha 值} ): Boolean;        {是否成功设置} 

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//举例(控制外部程序的透明度, 用计算器举了个例子): unit Unit1; interface uses   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,   Dialogs, StdCtrls; type   TForm1 = class(TForm)     Button1: TButton;     Button2: TButton;     procedure Button1Click(Sender: TObject);     procedure Button2Click(Sender: TObject);   end; var   Form1: TForm1; implementation {$R *.dfm} {设定计算器的 Alpha 透明} procedure TForm1.Button1Click(Sender: TObject); var   h: HWND;   FormStyle: Integer; begin   h := FindWindow('SciCalc', nil);   FormStyle := GetWindowLong(h, GWL_EXSTYLE);   SetWindowLong(h, GWL_EXSTYLE, FormStyle or WS_EX_LAYERED);   SetLayeredWindowAttributes(h, 0, 128, LWA_ALPHA); end; {设定计算器中的白色透明} procedure TForm1.Button2Click(Sender: TObject); var   h: HWND;   FormStyle: Integer; begin   h := FindWindow('SciCalc', nil);   FormStyle := GetWindowLong(h, GWL_EXSTYLE);   SetWindowLong(h, GWL_EXSTYLE, FormStyle or WS_EX_LAYERED);   SetLayeredWindowAttributes(h, clWhite, 255, LWA_COLORKEY); end; end.

WinAPI: SetLayeredWindowAttributes - 设置窗口的透明
这是来宾 Dolby 在 http://www.cnblogs.com/del/archive/2008/03/08/1081295.html#1096814 询问的问题.
//声明:
SetLayeredWindowAttributes(
  Hwnd: THandle;   {窗口句柄}
  crKey: COLORREF; {透明色}
  bAlpha: Byte;    {Alpha 值}
  dwFlags: DWORD   {LWA_COLORKEY(=1)表示使用透明色; LWA_ALPHA(=2)表示使用 Alpha 值}
): Boolean;        {是否成功设置}


//举例(控制外部程序的透明度, 用计算器举了个例子):
unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{设定计算器的 Alpha 透明}
procedure TForm1.Button1Click(Sender: TObject);
var
  h: HWND;
  FormStyle: Integer;
begin
  h := FindWindow('SciCalc', nil);
  FormStyle := GetWindowLong(h, GWL_EXSTYLE);
  SetWindowLong(h, GWL_EXSTYLE, FormStyle or WS_EX_LAYERED);
  SetLayeredWindowAttributes(h, 0, 128, LWA_ALPHA);
end;

{设定计算器中的白色透明}
procedure TForm1.Button2Click(Sender: TObject);
var
  h: HWND;
  FormStyle: Integer;
begin
  h := FindWindow('SciCalc', nil);
  FormStyle := GetWindowLong(h, GWL_EXSTYLE);
  SetWindowLong(h, GWL_EXSTYLE, FormStyle or WS_EX_LAYERED);
  SetLayeredWindowAttributes(h, clWhite, 255, LWA_COLORKEY);
end;

end.

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.Samples.Spin, Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    SpinEdit1: TSpinEdit;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}


procedure TForm1.Button1Click(Sender: TObject);
var
  h: HWND;
  FormStyle: Integer;
begin
  h := FindWindow(PChar(Edit1.Text), nil);
  FormStyle := GetWindowLong(h, GWL_EXSTYLE);
  SetWindowLong(h, GWL_EXSTYLE, FormStyle or WS_EX_LAYERED);
  SetLayeredWindowAttributes(h, 0, SpinEdit1.Value, LWA_ALPHA);
end;

end.

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 177
  ClientWidth = 352
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Edit1: TEdit
    Left = 8
    Top = 8
    Width = 121
    Height = 21
    TabOrder = 0
    Text = 'Edit1'
  end
  object Button1: TButton
    Left = 176
    Top = 8
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 1
    OnClick = Button1Click
  end
  object SpinEdit1: TSpinEdit
    Left = 8
    Top = 48
    Width = 121
    Height = 22
    MaxValue = 0
    MinValue = 0
    TabOrder = 2
    Value = 0
  end
end