C 辅导:制作透明窗体

文章作者 100test 发表时间 2008:03:29 13:53:17
来源 100Test.Com百考试题网

1.重载CreateParams函数，设置透明风格
2.然后重载它的WM_ERASEBKGND消息。
代码片段：

.h File
class TYourForm:public TForm
{
private:
void __fastcall WMNC(TMessage &.Message).
public:
__fastcall TYourForm(TComponent *Owner).
BEGIN_MESSAGE_MAP
VCL_MESSAGE_HANDLER(WM_ERASEBKGND,TMessage,WMNC).
END_MESSAGE_MAP(TForm).
protected:
virtual void __fastcall CreateParams(TCreateParams &.Params).
}


.cpp File

void __fastcall TYourForm::CreateParams(TCreateParams &.Params)
{
TForm::CreateParams(Params).
Params.EX_STYLE|=WS_EX_TRANSPARENT.
}
void __fastcall TYourForm::WMNC(TMessage &.Message)
{
SetBkMode(GetWindowDC(this->Handle),OPAQUE).
ReleaseDC(this->Handle,GetWindowDC(this->Handle)) .
Messgae.Result=1.
}