Thread: Why is this crashing on my face?

Code:

void Save(HWND hwnd)
{
	
	//open the Save As prompt, which is built in in windows (set it up here)
	OPENFILENAME ofn;
    char szFileName[MAX_PATH] = "";

    ZeroMemory(&ofn, sizeof(ofn));

    ofn.lStructSize = sizeof(ofn);
    ofn.hwndOwner = hwnd;
    ofn.lpstrFilter = "Text Files (*.txt)\0*.txt\0All Files (*.*)\0*.*\0";
    ofn.lpstrFile = szFileName;
    ofn.nMaxFile = MAX_PATH;
    ofn.Flags = OFN_EXPLORER |OFN_OVERWRITEPROMPT;
    ofn.lpstrDefExt = "txt";
    if(GetSaveFileName(&ofn)) //Open The Save As Prompt
    {

	 HWND DialogBoxH;
	
	
	//Get the info on the Edit Box

	 int len = GetWindowTextLength(DialogBoxH=GetDlgItem(hwnd, IDC_EDIT2));//Use GetDlgItem(hwnd, IDC_TEXT)
															  //to get a handle to the 
															  //Edit Box
     if(len > 0)//if it's more than zero, meaning it has characters
     {
        
        char* buf;

        buf = (char*)GlobalAlloc(GPTR, len + 1);//we add one here for the null 
        GetDlgItemText(hwnd, IDC_EDIT2, buf, len + 1);//get the text from the edit box
		memcpy(Cliente.ClientName,buf,strlen (buf)); //copy the text from buf to the struct
		
		MessageBox (DialogBoxH, Cliente.ClientName,"Something", MB_OK);
		
        //... do stuff with text ...

        GlobalFree((HANDLE)buf);
	 }

	 LPCTSTR FileName;

	 HANDLE FileSave=NULL;
	 BOOL Success;
	 FileSave=CreateFile(FileName, GENERIC_WRITE, 0, NULL,  CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
	 
	  DWORD dwWritten;

	 if (FileSave!= INVALID_HANDLE_VALUE)
	 {
		 WriteFile(FileSave, &Cliente, sizeof Cliente,&dwWritten, NULL); 
	 }




	
        // Do something usefull with the filename stored in szFileName 
    } 
}

Originally posted by golfinguy4
Use your debugger to find the line it crashes on.

::whispers::: read my post on the GD forums.........


I don't have to use a debugger, though I will read a tutorial I found on it.

VC++.......

I had that problem too at one time...then I read some obscure MS doc which stated that lpstrFile[0] must be initialized to zero ELSE SOMETHING UNDEFINED may happen! Strangely enough, that was it (for me anyway). Give it a go.

Learn Debugging NOW!!!!!!!!!!!!!!!

It would take me hours to find that problem if I looked at the code. I could isolate it in minutes with the debugger.

VC++ debugger is very good.

Make sure you are building a debug version of your app.

Get the cursor on the line

ZeroMemory(&ofn, sizeof(ofn));

press F9. This will place a break point on that line. A red dot should appear.

Run the app.
Move thru it until you can get to call this problem function. When you do the complier will open on the line with the break point.

Make sure you can see the watch window in VC++ v6 is under View->Debug Window->Watch.

You can drag variables into this window to see their value or just hover the mouse over them.

Use F10 to step a single line of code.
Continue until the crash occurs.



PS
I think your problem is the filter
Try
"Text Files (*.txt)\0*.txt\0All Files (*.*)\0*.*\0\0"

>>obscure MS doc which stated that lpstrFile[0] must be initialized to zero

I set it to the name I suggest the user save as and have no problems.

Whohoo!!!!!!!!

I caught the problem with my handy debugger, we have a new found friendship now. Hehehehe!!!

I was passing FileName to createfile which didn't contain anything. I caught that with our handy debugger....!!!!

look

Code:

	 LPCTSTR FileName;

	 HANDLE FileSave=NULL;
	 BOOL Success;
	 FileSave=CreateFile(FileName, GENERIC_WRITE, 0, NULL,  CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

Thanks guys.