Hi all,
I am using eVC++ 4.0, and i've dynamically created a CListView like this:
Code:
lv.Create(0,_T(""),WS_CHILD|WS_VISIBLE,r,this,5);
but I dont know how to handle the events of this control... any ideas??
Mohammad
To get events from a listview (win32) I normally subclass it. I use the subclassing routine to post a message back to the parent when the user is doing something like tapping on it, then the windows routine can check whats selected etc and act on it. Is subclassing possible in mfc ?( I don't use it).
Thank u
but can anybody post some code??
thnx
Ok, I am a bit lazy to look up code at the moment, but here's something:
Yes, subclassing is possible in MFC. You just derive your class from the basic class provided like this:
Code:
class MyListView : pubic CListView
Then you add message handlers in the normal matter.
EDIT: The following passage is incorrect:
But I think subclassing may not be necessary in you case. List box controls send WM_COMMAND messages with notifications of major events like selection change to the parent window. All you have to do is to create a WM_COMMAND handler in your parent class.
Sorry I was thinking of ListBox not list view when I wrote it.
To manually add message handlers you need to put macros like ON_MESAGE or ON_COMMAND in the DECLARE_MESSAGE_MAP section of the class cpp file. All the detaisl are available on MSDN.
Are you saying that a listview will send the same WM_COMMAND as a list box in mfc? Dose this also happen in win32 made listviews. I have always thought it was a bit too tedious to find out when the user taps an item in the listview.
After reading your post levenum I had a quick look and it says that a WM_NOTIFY gets sent to the parent with a LVN_ITEMCHANGED for example. I had not used the LVN_**** because when I looked at them there was none that seem to deal with selections. I would guess that LVN_ITEMACTIVATE or LVN_ODSTATECHANGED would be usefull for this but then a second tap would not be picked up still leaving me wanting subclassing in many situations to get the users tap.
Ok, I have read what u wrote guys and my problem is almost solved, I used the OnNotify() method to handle messages sent from child controls like this:
Code:
BOOL CTest2Dlg::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{
// TODO: Add your specialized code here and/or call the base class
if(wParam ==5 ) //5 is control ID
{
NMHDR *ph =(NMHDR*)lParam;
if(ph->code==NM_CLICK)
MessageBox("Click");
else if(ph->code==HDN_ITEMCLICK)
MessageBox("Item Click");
else
{
CString str;
str.Format("%d",ph->code);
MessageBox(str);
}
}
return CDialog::OnNotify(wParam, lParam, pResult);
}
Now there still a very small prolem: what messages should I handle for 'Selected Item Changed' event ?? I know its easy but I couldnt find it
Regards
mohgdeisat: I am sorry, I made a mistake about WM_COMMAND.
OdeeanRDeathshead is right, I was thinking of a list box not list view.
To make up for this, here is some sample code from a win32 dialog app that uses list view control. I hope it will be of some help:
Code:
//this is from the dialog window function:
case WM_NOTIFY: //handle events:
nmhdr = (LPNMHDR)lParam;
switch (nmhdr->idFrom)
{
case IDC_LEDLIST: //list control ID.
return OnLEDListEvent(hwndDlg, (LPNMLISTVIEW)lParam);
break;
}
break;
BOOL OnLEDListEvent(HWND hwndDlg, LPNMLISTVIEW nmlv)
{
/////
// Handles list view control notification messages
switch (nmlv->hdr.code)
{
case LVN_ITEMCHANGED:
return OnLEDListItemChanged(hwndDlg, nmlv);
break;
}
return 0;
}
BOOL OnLEDListItemChanged(HWND hwndDlg, LPNMLISTVIEW nmlv)
{
if (ListView_GetSelectionMark(nmlv->hdr.hwndFrom) != nmlv->iItem) return 0;
/* do what you need here */
return 0;
}
Don't mind the fact that I used 3 different functions. This is part of a bigger program and I am trying to keep things well organized without resorting to classes.
As I understand it, LVN_ITEMCHANGE is received for different reasons so I try to handle only the one coming from selected item. LVN_ITEMACTIVATE is only sent when you double click the item so if you just want to catch selection change you need to use LVN_ITEMCHANGE.
Once again, sorry for confusing you before.
thanx pals, good job!!!
I think my problem is now solved with ur help :wink:
Mohammad
Ok guys, I said that my problem was solved, yet, another problem arises...
When the list view is in the report mode, how can I determine when a header button is clicked, and determine which one was clicked???????
thanx in advance
To identify a header column click, you need to handle the WM_NOTIFY/HDN_ITEMCLICK message. Normally this message will be received by the header's parent control (i.e. the listview) -- some frameworks may redirect the message to the header control itself. I haven't worked with MFC in 10 years so I can't really if it reflects notification messages back to the control.
If you're trying to implement column sort, do yourself a favor and check out the Windows Template Library (WTL) at sourceforge.net. It's a set of C++ template classes that provide a thin yet useful wrapper around the standard Windows UI components. One of the classes is a sortable listview control. I've been using WTL with big Windows for more than 5 years -- you couldn't pay me to go back to MFC.
hi,
I have seen the WTL library and it seems very useful and time-saver, but I have a couple of questions about it:
1. can WTL 8.0 be installed with VC++ 6.0, specifically the appwizard stuff??how?? I see only javascript files of vc7.0 and 7.1 and 8.0!!
2. is there a good documentation about those classes??
Mohammad
I don't know about WTL 8; I'm still using WTL 7.5 with VS .Net 2003 for all my Win32 development. My guess is that it wouldn't work too well, as WTL is based on ATL, which has substantially changed between VC 6 and 7.
Good references for WTL include www.codeproject.com/wtl, and the WTL group over at Yahoo groups (reflected at www.gmane.org).
Hey all, I create an array list, and I populate the array list with 3 items.
When I call .remove(index) on the array list it doesn't error, but then I call .size() on the next line and it's the same size!
Sooooo what exactly got removed? Is there something I'm missing with ArrayLists?
Please help
Try stepping through the code with a debugger. Compare the state of the list before and after the call.
+1 on using the debugger.
Are you checking for IndexOutOfBoundsException with try/catch?
I would like to point out that the example at google code of a Collada Loader is misleading. (code.google.com/p/androidcolladaloader)
The way to handle data in the characters(char[] ch, int start, int length) callback funtion should be done in the endElement(String uri, String localName, String name) callback function. This is because data between XML tags can be splitted by the sax xml parser and then call the characters function multiple times. The solution to this I found at coderanch:
coderanch.com/t/432967/XML/Missing-characters-SAX-Parser
Where Ulf Dittmer suggests:
Yes. The one you have apparently assumes that all text data is returned in a single chunk (I can't tell for sure since you didn't post the full code of the method). You need to change it so that it still works if the text is returned in several chunks. One way to do that would be to append the text to a StringBuffer (which would be field in your handler class). Once the end element of whatever tag surrounds this text is reached, you can handle the text itself.
Click to expand...
Click to collapse
An example of working with a stringBuffer in the characters function is shown here:
onjava.com/pub/a/onjava/2002/06/26/xml.html?page=2
Note that the start and length argument given with the characters call back function are not there for nothing!
I created listView item which contain list using following command and watched it working:
lv1=(ListView)findViewById(R.id.listView_entries);
setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_multiple_choice, PENS));
However, I wonder if it is possible to have it attribute so that
clicking on single item will move to another activity, however clicking on the checkbox will highlight the listitem without moving to another activity?
Currently, I implemented onclick function on listView so that clicking on any item will go to another activity. However, does clicking on the checkbox on each item.
Thanks,
I'm not sure I follow you completely on this, but it should do what you want if you supply an OnClickHandler for the checkbox. You may need to expand the padding on the checkbox control to ensure that you hit it and not the list entry around it.
hey i think i found a solution to this, i found it in the pro android training manual. i will post once i am able to integrate into my code. thx.
Hi guys.
New to Android Development and was wondering if there was some way of taking the users input to create an activity? For example say the user is going through the process of setting up a profile of themself. One of the questions is "how many pets do you have?". The user inputs "4" and then clicks the 'Next' button (which opens the next activity).
How would I take the users input of "4" to create four editText objects in the next activity so that the user can now input the name's of his/her's pets?
I'm an ok-ish programmer (have never touched XML before) so you don't need to go into detail I just don't know how I would access this variable to create the four editText objects. From what I've found you can't add strings to the resources at runtime.
Don't bother replying, I've solved my problem. Just need to create a dynamic layout in JAVA