要使用此单元,在主窗体和OnModalBegin调用_GrayForms中放置一个TApplication组件,然后在OnModalEnd中调用_NormalForms方法.

这是一个非常简单的例子,可以很容易地复杂化.检查多个通话级别等….

对于诸如系统(打开,保存等)对话框,您可以在try …中封装对话框execute方法,最后阻止调用相应的函数以获得类似的反应.

该单元应该在Win2k,WinXP,Vista上工作,甚至可以在Win7上工作.

瑞安.

unit GrayOut;

interface

procedure _GrayForms;
procedure _GrayDesktop;
procedure _NormalForms;

implementation

uses windows,classes,forms,Contnrs,Types,Graphics,sysutils;

var
   gGrayForms : TComponentList;

procedure _GrayDesktop;
var
   loop : integer;
   wScrnFrm : TForm;
   wForm : TForm;
   wPoint : TPoint;

begin
   if not assigned(gGrayForms) then
   begin
      gGrayForms := TComponentList.Create;
      gGrayForms.OwnsObjects := true;

      for loop := 0 to Screen.MonitorCount - 1 do
      begin
         wForm := TForm.Create(nil);
         gGrayForms.Add(wForm);

         wForm.Position := poDesigned;
         wForm.AlphaBlend := true;
         wForm.AlphaBlendValue := 64;
         wForm.Color := clBlack;
         wForm.BorderStyle := bsNone;
         wForm.Enabled := false;
         wForm.BoundsRect := Screen.Monitors[loop].BoundsRect;
         SetWindowPos(wForm.handle,HWND_TOP,SWP_NOSIZE or SWP_NOMOVE);
         wForm.Visible := true;
      end;
   end;
end;

procedure _GrayForms;
var
   loop : integer;
   wScrnFrm : TForm;
   wForm : TForm;
   wPoint : TPoint;
   wScreens : TList;

begin
   if not assigned(gGrayForms) then
   begin
      gGrayForms := TComponentList.Create;
      gGrayForms.OwnsObjects := true;

      wScreens := TList.create;
      try
         for loop := 0 to Screen.FormCount - 1 do
            wScreens.Add(Screen.Forms[loop]);

         for loop := 0 to wScreens.Count - 1 do
         begin
            wScrnFrm := wScreens[loop];

            if wScrnFrm.Visible then
            begin
               wForm := TForm.Create(wScrnFrm);
               gGrayForms.Add(wForm);

               wForm.Position := poOwnerFormCenter;
               wForm.AlphaBlend := true;
               wForm.AlphaBlendValue := 64;
               wForm.Color := clBlack;
               wForm.BorderStyle := bsNone;
               wForm.Enabled := false;
               wForm.BoundsRect := wScrnFrm.BoundsRect;
               SetWindowLong(wForm.Handle,GWL_HWNDPARENT,wScrnFrm.Handle);
               SetWindowPos(wForm.handle,wScrnFrm.handle,SWP_NOSIZE or SWP_NOMOVE);
               wForm.Visible := true;
            end;
         end;
      finally
         wScreens.free;
      end;
   end;
end;

procedure _NormalForms;
begin
   FreeAndNil(gGrayForms);
end;

initialization
   gGrayForms := nil;

end.