c++builder Form重载WindowProc、WndProc 截获消息

c++builder 重载WindowProc、WndProc 截获消息

方法一WindowProc

void __fastcall  myWindowProc(Messages::TMessage &msg); //增加
Classes::TWndMethod OldWindowProc;  //增加

void __fastcall  TForm1::myWindowProc(Messages::TMessage &msg)
 {
   if (msg.Msg == WM_MOUSEWHEEL)
   {
     //::MessageBox(NULL,"OK","Message",0);  //测试
     Caption = Now();
   }

else
     OldWindowProc(Message);
 }

void __fastcall TForm1::FormCreate(TObject *Sender)
{

OldWindowProc=Edit1->WindowProc;
  Edit1->WindowProc=myWindowProc;        
}

方法二 MESSAGE_MAP

class TForm1 : public TForm
{
__published: // IDE-managed Components
        TEdit *Edit1;
private: // User declarations
void __fastcall OnEditMouseWell(TMessage &msg);
BEGIN_MESSAGE_MAP

MESSAGE_HANDLER(WM_MOUSEWHEEL, TMessage, OnEditMouseWell)

END_MESSAGE_MAP(TForm)  //TForm 换成TEdit

public:  // User declarations
        __fastcall TForm1(TComponent* Owner);
};

void __fastcall TForm1::OnEditMouseWell(TMessage &msg)
 {
   if(String(ActiveControl->ClassName())=="TEdit")  //所有的Edit
      Caption   = Now(); //测试

//TForm::Dispatch(&Msg);

}

方法三 重载 WndProc

private: // User declarations
     void __fastcall WndProc(Messages::TMessage &msg);

void __fastcall TForm1::WndProc(Messages::TMessage &msg)
{
  if (msgMsg == WM_MOUSEWHEEL && msg.WParam )
    {
      Caption = Now();
    }
    TForm::WndProc(msg);
}

四、ApplicationEvents控件

窗体上放置ApplicationEvents1控件，在ApplicationEvents1Message事件里判断。

void __fastcall TForm3::ApplicationEvents1Message(tagMSG &Msg, bool &Handled)
{
    if (Msg.hwnd == this->DBGrid1->Handle && Msg.message == WM_MOUSEWHEEL)
        this->Caption = Now();
}

WM_LBUTTONDOWN