.NET/WinForms Custom Form Border with Minimize Animation - c++

Question

I know I've seen this asked before, but the answers have been inconclusive or unsatisfactory (from what I could see), so I'd like to pose my situation here. I'm creating a program that has a custom form border (i.e. Form Border Style = None with our own controls around it). The program doesn't have the minimize/close animations, but just snaps, instead.
It is a .NET form (using C++/CLR) - is there something I can do? I've seen other programs do this (for example, Photoshop CS6/CC have the restore animation, but not the minimize one).
Is there a property/style I can apply by overriding the CreateParams? I'm game for "hacky" methods, but changing the form border style in a way that lets the user temporarily see the border isn't a viable option here.
Thanks in advance.

Answer 1

I ended up using a custom animation and figured I would share the relevant code. The following override of the WndProc catches minimizes/restores (including from clicking/double clicking in the taskbar). Be aware, setting the WindowState WILL NOT trigger this - you have to manually send the SC_MINIMIZE lpa with the WM_SYSCOMMAND to the window (or manually animate it). The entire animation code, timer included is below.
//Define a variable so it knows what animation is happening
short fade_mode = 0; //0 is fade in, 1 is minimize, 2 is close
short close_on_close = FALSE; //a variable to tell the close handler to re-animate or not - this allows this->Close(); to trigger the animation but avoids a loop.
//The WndProc
protected: virtual void WndProc(System::Windows::Forms::Message% msg) override {
switch (msg.Msg) {
case WM_SYSCOMMAND:
switch (msg.WParam.ToInt32()) {
case SC_MINIMIZE:
msg.Result = IntPtr::Zero;
fade_mode = 1;
fadetimer->Start();
return;
break;
}
break;
case WM_ACTIVATE: {
if (HIWORD(msg.WParam.ToInt32()) == 0) { //because non-zero wpa here means the form is minimized
this->WindowState = FormWindowState::Normal;
fade_mode = 0;
fadetimer->Start();
msg.Result = IntPtr::Zero;
return;
}
}
}
Form::WndProc(msg);
}
//The button event handlers
private: System::Void btn_close_Click(System::Object^ sender, System::EventArgs^ e) {
this->Close();
}
private: System::Void btn_minimize_Click(System::Object^ sender, System::EventArgs^ e) {
SendMessage(HWND(this->Handle.ToPointer()), WM_SYSCOMMAND, SC_MINIMIZE, NULL);
}
//The event animation code itself (set to a tick of 10ms) and the form closing handler:
private: System::Void fadetimer_Tick(System::Object^ sender, System::EventArgs^ e) {
if (this->IsDisposed == true) { //In the event that the form opened/closed quickly and has not stopped properly, clean up to avoid crashes.
fadetimer->Stop();
return;
}
switch (fade_mode) {
case 0: //fading in
if (this->Opacity < 1)
this->Opacity += 0.2;
else {
fade_mode = -1;
fadetimer->Stop();
}
break;
case 1: //minimizing
if (this->Opacity > 0)
this->Opacity -= 0.2;
else {
fade_mode = -1;
fadetimer->Stop();
this->WindowState = Windows::Forms::FormWindowState::Minimized;
}
break;
case 2: //closing
if (this->Opacity > 0)
this->Opacity -= 0.2;
else {
fade_mode = -1;
fadetimer->Stop();
close_on_close = TRUE;
this->Close();
}
break;
}
}
private: System::Void loginform_FormClosing(System::Object^ sender, System::Windows::Forms::FormClosingEventArgs^ e) {
if (close_on_close == FALSE) {
e->Cancel = true;
fade_mode = 2;
fadetimer->Start();
}
}
Be sure to set your form's opacity to 0% by default - it should automatically fade in when it's first created/shown (mine does, I can't remember if I've done something else that makes it so).