窗体透明度设置

效果

  

新建对话框程序

修改对话框

WindowAlphaSettingDlg.h : 头文件

public:
CSliderCtrl m_sld;
afx_msg void OnNMReleasedcaptureSlider1(NMHDR *pNMHDR, LRESULT *pResult);

WindowAlphaSettingDlg.cpp : 实现文件

BOOL CWindowAlphaSettingDlg::OnInitDialog()

//窗口置顶
::SetWindowPos(m_hWnd,HWND_TOPMOST,0,0,0,0,SWP_NOSIZE|SWP_NOMOVE);

//控件范围
m_sld.SetRange(10,255);
m_sld.SetPos(128);

//窗口样式
SetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE,GetWindowLong(this->GetSafeHwnd(),GWL_EXSTYLE)^0x80000);
HINSTANCE hInst = LoadLibrary("User32.DLL");
if (hInst)
{
typedef BOOL (WINAPI *MYFUNC)(HWND,COLORREF,BYTE,DWORD);
MYFUNC fun = NULL;
//取得SetLayeredWindowAttributes函数指针
fun = (MYFUNC)GetProcAddress(hInst,"SetLayeredWindowAttributes");
if(fun) fun(this->GetSafeHwnd(),0,128,2);
FreeLibrary(hInst);
}

void CWindowAlphaSettingDlg::OnNMReleasedcaptureSlider1(NMHDR *pNMHDR, LRESULT *pResult)
{
// TODO: 在此添加控件通知处理程序代码
BYTE eff = (BYTE)m_sld.GetPos();
HINSTANCE hInst = LoadLibrary("User32.DLL");
if (hInst)
{
typedef BOOL (WINAPI *MYFUNC)(HWND,COLORREF,BYTE,DWORD);
MYFUNC fun = NULL;
//取得SetLayeredWindowAttributes函数指针
fun = (MYFUNC)GetProcAddress(hInst,"SetLayeredWindowAttributes");
if(fun) fun(this->GetSafeHwnd(),0,eff,2);
FreeLibrary(hInst);
}

CString str;
str.Format("%d%%",100*eff/255);
GetDlgItem(IDC_STATIC1)->SetWindowText(str);

*pResult = 0;
}