[windows] Implement close method #56

Author: lijy91

windows/window_manager.cpp

@@ -46,6 +46,7 @@ class WindowManager {
   HWND GetMainWindow();
   void WindowManager::SetAsFrameless();
   void WindowManager::WaitUntilReadyToShow();
+  void WindowManager::Close();
   void WindowManager::Focus();
   void WindowManager::Blur();
   void WindowManager::Show();
@@ -132,6 +133,11 @@ void WindowManager::SetAsFrameless() {
 
 void WindowManager::WaitUntilReadyToShow() {}
 
+void WindowManager::Close() {
+  HWND hWnd = GetMainWindow();
+  CloseWindow(hWnd);
+}
+
 void WindowManager::Focus() {
   HWND hWnd = GetMainWindow();
   if (IsMinimized()) {

windows/window_manager_plugin.cpp

@@ -221,6 +221,9 @@ void WindowManagerPlugin::HandleMethodCall(
   } else if (method_name.compare("setAsFrameless") == 0) {
     window_manager->SetAsFrameless();
     result->Success(flutter::EncodableValue(true));
+  } else if (method_name.compare("close") == 0) {
+    window_manager->Close();
+    result->Success(flutter::EncodableValue(true));
   } else if (method_name.compare("focus") == 0) {
     window_manager->Focus();
     result->Success(flutter::EncodableValue(true));