Managed C++/CLI

Dewm Solo wrote:

if ( (myStream = this->openFileDialog1->FileName) != nullptr )

Dewm Solo wrote:

myStream->ToString()

Mark Salsbery
Microsoft MVP - Visual C++

Mark Salsbery wrote:

openFileDialog1->FileName should be compared to String::Empty - the default value, not nullptr.

Mark Salsbery wrote:

Why?

Mark Salsbery wrote:

When the app goes unresponsive, if you break in the debugger, where's
the current execution point at?

<br />
String^ m_Path = gcnew String();<br />

<br />
public ref class TestClass {<br />
	public: <br />
		TestClass(String^ jj);<br />
		~TestClass();<br />
<br />
	private:<br />
		String^ sPath;<br />
	};<br />

<br />
TestClass::TestClass(String^ jj)<br />
	{<br />
		//<br />
	}<br />
<br />
	TestClass::~TestClass()<br />
	{<br />
		//<br />
	}<br />

<br />
private: System::Void button2_Click(System::Object^  sender, System::EventArgs^  e) {<br />
				 MFG::TestClass^ ttt = gcnew MFG::TestClass("test");<br />
				 MessageBox::Show("instance created");<br />
			 }<br />

public delegate bool LP_EnumWindowsProc(IntPtr hWnd, int lParam);
 
// this call fills list with all visible windows
EnumChildWindows(hWnd,  new LP_EnumWindowsProc(CollectVisibleWindows), 0);
 
private static bool CollectVisibleWindows(IntPtr hWnd, int lParam) {
	if(IsWindowVisible(hWnd)) list.Add(hWnd);
	return true;	// please continue enumeration !
}

delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);

[DllImport("user32", CharSet=CharSet::Ansi, SetLastError=true, ExactSpelling=true)]	static int EnumChildWindows(IntPtr hWndParent, EnumWindowsProc^ lpEnumFunc, IntPtr lParam){}

bool CALLBACK EnumWindowsCallback(IntPtr hWnd, IntPtr lParam){}

void UseIt() //errors
{
	EnumWindowsProc^ fp = gcnew EnumWindowsProc(EnumWindowsCallback);
	EnumChildWindows(Handle, fp, IntPtr::Zero);
}

// Delelgate
delegate bool EnumWindowProc(IntPtr hWnd, Int32 lParam);
 
// Global callback function
bool GlobalCallback(IntPtr hWnd, Int32 lParam)
{
	// ...
	
	return true;
}
 
DllImport("User32.DLL")]
public static extern void EnumWindows(EnumWindowProc callback, Int32 lParam);
 
// Your code ...
 
// Using global function syntax for creating delegate
EnumWindowProc^ ewp += gcnew EnumWindowProc(&GlobalCallback);
 
// ,,,
 
// Invoke Delegate
EnumWindows(ewp, 0);