Enlightening. Thanks for your response Stoitcho. I think I will use the
index then to "uniquely" identify. Any way I could see an example in C# for
CB_GETLBTEXT? I think I have it but the method does not work with internet
explorer's trident combo. All it seems to give is giberish. It seems to
work with windows forms.
Here is what I am doing to get the list values:
public const UInt32 CB_GETCOUNT = 0x0146;
public const UInt32 CB_GETCURSEL = 0x0147;
public const UInt32 CB_GETLBTEXT = 0x0148;
public const UInt32 CB_GETLBTEXTLEN = 0x0149;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(HandleRef hWnd, uint Msg, IntPtr wParam,
IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(HandleRef hWnd, uint Msg, IntPtr wParam,
StringBuilder lParam);
public static List<ListItemVals> GetListItems(IntPtr controlPointer, object
sender)
{
int count = 0;
List<ListItemVals> retVal = new List<ListItemVals>();
ListItemVals item = new ListItemVals();
IntPtr zero = new IntPtr(0);
//Get the count of items in the list
IntPtr ptr = SendMessage(GetHandleRef(controlPointer, sender), CB_GETCOUNT,
zero, zero);
count = ptr.ToInt32();
for (int i = 0; i < count; i++)
{
item = GetValueFromCombo(controlPointer, sender, i);
retVal.Add(item);
}
return retVal;
}
public static ListItemVals GetValueFromCombo(IntPtr pointer, object sender,
int index)
{
//List<ListItemVals> retVal = new List<ListItemVals>();
int len = 0;
StringBuilder sb = new StringBuilder();
ListItemVals item = new ListItemVals();
IntPtr wParam = new IntPtr(index);
IntPtr zero = new IntPtr(0);
//Get the count of items in the list
IntPtr ptr = SendMessage(GetHandleRef(pointer, sender), CB_GETLBTEXTLEN ,
wParam, zero);
len = ptr.ToInt32();
sb.Capacity = len;
IntPtr txtPtr = SendMessage(GetHandleRef(pointer, sender), CB_GETLBTEXT,
wParam, sb);
//Get the list item
item.textValue = sb.ToString();
item.itemValue = wParam.ToInt32();
//return the value
return item;
}
Stoitcho Goutsev (100) said:
Matt,
you can attach a user data which is 32 bit number. What this number means
is up to you. It could be a number or it could be a pointer to a bigger
data structure. Ususally this is used in the case of owner-drawn
comboboxes when the style CBS_HASSTRINGS is not set.
I'm pretty sure WindowsForms uses that for keeping references with the
items, but I doubt it has anything to do with the vlue and display members
Stoitcho Goutsev (100)
ME said:
Thanks for your input. What would the "CB_GETITEMDATA" message do then?
It appears that the "CB_GETLBTEXT" message retrieves the text value of
the item. I can not seem to find any examples of "CB_GETITEMDATA" being
used.
http://msdn.microsoft.com/library/d...reference/comboboxmessages/cb_getitemdata.asp
Thanks,
Matt
Stoitcho Goutsev (100) said:
Matt,
You cannot read it from Windows native API. They don't exist there.
Native windows combobox control has only one value and this is the text
that you see. DisplayMember and ValueMember are part of the .NET
control.
--
Stoitcho Goutsev (100)
Please forgive my use of the wrong term. ValueMember and DisplayMember
are used to BIND the values in .NET combobox on form, however in Visual
Basic 6 you had ItemData and List. In ASP.NET you have Text and Value
properties of the Item object (DropDownList.Items[x]). The point is
there are many ways to make a combo have two corresponding values, a
display version (text) and an underlining programmatic version (value).
I would like to know how to read both sets of data from a combo using
the windows api.
I have a web page which I need to generate a new UI for. Unfortunately
the page can not be modified by me, the end user. The page contains
combos (or dropdownlists) that have items in no logical order (over 100
items). I want to display a form to a user with the same list, just
alphabetized. When a user selects the item in my list I want to
programmatically select the item in the original mixxed up list. I
want to make sure that if any value in the list has the same display
TEXT, that I will be able to determine which one is which based on the
other itemVALUE associated with it.
The need for a windows forms version is because this also occurs a
windows form appliction with a similar problem. The programmers were
idiots and it will be at least a year before they even think about
fixing thier list boxes. I want to write a app to work with both.
Thanks,
Matt
Matt,
What are these ListItemValue and ListItemText on the WindowsForms'
combobox?
--
Stoitcho Goutsev (100)
I am new to interop services as well as the Windows API in general.
What is
the proper way to obtain the ListItemValue and the ListItemText using
the
windows API? I would like to be able to read a combo's list values
from a
windows form application (ComboBox) and also from a combo on a web
page
(Internet Explorer_TridentCmboBx). I can not seem to locate much
documentation or even code examples. I am using C#.
Thanks
Matt
