重载FormMain::WndProc时ShowWindow有时失效

[天籁晓国]

c++ builder中 ShowWindow有时会失效 Application->onmessage 已被重载

void __fastcall TFormMain::WndProc(TMessage & Message)
{
if (Message.WParam == SC_MINIMIZE)
{
ShowWindow(Application->Handle, SW_MINIMIZE);//这句代码有时失效
}
TFormMain::Dispatch(&Message);
}

[天籁晓国]

改为TForm::WndProc(Message)后最小化窗口依然有问题 这是相关代码请大家看看到底哪的逻辑有问题 int Count = 0; //--------------------------------------------------------------------------- __fastcall TForm5::TForm5(TComponent* Owner) : TForm(Owner) { } //--------------------------------------------------------------------------- void __fastcall TForm5::WndProc(TMessage & Message) { if (Form6) return; if (Message.WParam == SC_MINIMIZE) { ShowWindow(Application->Handle, SW_MINIMIZE); Message.WParam = 0; } TForm::WndProc(Message); } // --------------------------------------------------------------------------- void __fastcall TForm5::MyMessage(tagMSG &Msg, bool &Handled) { if (Form6) return; switch(Msg.message) { case WM_SYSCOMMAND: if (Msg.wParam == SC_MINIMIZE) { ShowWindow(Application->Handle, SW_MINIMIZE); } Msg.wParam = 0; break; case WM_USER_A: Handled = true; if (Form6) return; Hide(); Application->CreateForm(__classid(TForm6), &Form6); Form6->ShowModal(); Form6 = NULL; Show(); Count = 0; break; } } void __fastcall TForm5::FormActivate(TObject *Sender) { Application->OnMessage = MyMessage; } //--------------------------------------------------------------------------- void __fastcall TForm5::FormDeactivate(TObject *Sender) { Application->OnMessage = OldEvent; } //--------------------------------------------------------------------------- void __fastcall TForm5::FormCreate(TObject *Sender) { OldEvent = Application->OnMessage; } //--------------------------------------------------------------------------- void __fastcall TForm5::Timer1Timer(TObject *Sender) { if (Form6) return; Count++; if (Count >= 20) { PostMessage(Handle, WM_USER_A, 0, 0); } else Edit1->Text = IntToStr(20 - Count); } //--------------------------------------------------------------------------- void __fastcall TForm5::WMA(TMessage & Message) { PostMessage(Handle, WM_USER_A, 0, 0); } void __fastcall TForm5::Button1Click(TObject *Sender) { PostMessage(Handle, WM_USER_A, 0, 0); } //--------------------------------------------------------------------------- void __fastcall TForm5::FormShow(TObject *Sender) { Application->OnMessage = MyMessage; } //--------------------------------------------------------------------------- 头文件中消息定义 MESSAGE void __fastcall WMA(TMessage & Message); TMessageEvent OldEvent; BEGIN_MESSAGE_MAP VCL_MESSAGE_HANDLER(WM_USER_A, TMessage, WMA) END_MESSAGE_MAP(TForm)

[ccrun.com]

TFormMain::Dispatch(&Message); 这一句，建议用： TFormMain的父类::WndProc(Message); // 比如 TForm::WndProc(Message); 来代替