Access violation writing location 0x00000000

[Farhan Ali]

Asalam o Alaikum: I have made a desktop application in c# which gets text from the controls like textboxes.on some forms it works fine but sometime gives this error Access violation writing location 0x00000000 how this error can be removed. Thanx

[rp_suman]

This will happen when you assign something to a NULL pointer. Put a break point and debug step by step. See the variable at the left of error happening line. Best Regards, Suman

[Farhan Ali]

It happens when this line executes SendMessage(lvwHwnd, LVM_GETITEMTEXT, selectedrow, _lvi); _lvi is the pointer which is not null it has some address. hopefully this info will help u to answer Thanx

[CPallini]

Seems the wrong forum (C++ one is more appropriate), anyway... you have to pass valid pointer to a valid LVITEM struct, i.e. a properly initialised struct (you have to take special care with pszText and cchTextMax members, the former must point to an allocated buffer, the latter must contain the size of the buffer itself, see MSDN [^]). Hope that helps. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.

[Luc Pattyn]

Hi, if you happen to send a message to another process, and that message needs an address, then that address must be valid in that process, not in the local process. whatever, publishing the entire method (and relevant data members) may allow us to comment. :)

Luc Pattyn [My Articles]