C++builder重载WndProc消息处理过程

发布: 2023-03-27 作者: admin 浏览: 71 评论: 0 分类: C++ 标签: WindowProc,WndProc,消息处理,MESSAGE_MAP,MESSAGE_HANDLER

C++builder 重载WindowProc、WndProc、MESSAGE_BAP等消息处理方法

方法一WindowProc
```js
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

```js
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

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