"Property value is not valid" when PropertyGridView tries to convert a string to a custom object type.

Question

Hi,
I have a problem with an PropertyGrid enum property that uses a type converter.
In general it works, but when I double clicking or using the scoll wheel,  an error message appears:
"Property value is not valid"
Details: "Object of type 'System.String' cannot be converted to type 'myCompany.myProject.CC_myCustomProperty."
I noticed that the CommitValue method (in PropertyGridView.cs) tries to convert a string value to a CC_myCustomProperty object.
Here is the code that causes the error (see line 33):
(Using the .net symbols from the PropertyGridView.cs file)
1
        internal bool CommitValue(GridEntry ipeCur, object value) {   
2
3
            Debug.WriteLineIf(CompModSwitches.DebugGridView.TraceVerbose,  "PropertyGridView:CommitValue(" + (value==null ? "null" :value.ToString()) + ")");   
4
5
            int propCount = ipeCur.ChildCount;  
6
            bool capture = Edit.HookMouseDown;  
7
            object originalValue = null;   
8
9
            try {   
10
                originalValue = ipeCur.PropertyValue;   
11
12
            catch {   
13
                // if the getter is failing, we still want to let  
14
                // the set happen.  
15
16
17
            try {  
18
                try {   
19
                    SetFlag(FlagInPropertySet, true);   
20
21
                    //if this propentry is enumerable, then once a value is selected from the editor,   
22
                    //we'll want to close the drop down (like true/false).  Otherwise, if we're  
23
                    //working with Anchor for ex., then we should be able to select different values  
24
                    //from the editor, without having it close every time.  
25
                    if (ipeCur != null &&   
26
                        ipeCur.Enumerable) {  
27
                           CloseDropDown();   
28
29
30
                    try {   
31
                        Edit.DisableMouseHook = true;  
32
/*** This Step fails because the commit method is trying to convert a string to myCustom objet ***/ 
33
                        ipeCur.PropertyValue = value;   
34
35
                    finally {   
36
                        Edit.DisableMouseHook = false;  
37
                        Edit.HookMouseDown = capture;   
38
39
40
                catch (Exception ex) {   
41
                    SetCommitError(ERROR_THROWN);  
42
                    ShowInvalidMessage(ipeCur.PropertyLabel, value, ex);  
43
                    return false;  
44
I'm stuck.
I was wondering is there a way to work around this? Maybe extend the string converter class to accept this?
Thanks in advance,
Eric

Answer 1

 
Hi,
Thank you for your post!  I would suggest posting your question in one of the MS Forums,
 MSDN Forums » Windows Forms » Windows Forms General
 located here:http://forums.microsoft.com/MSDN/ShowForum.aspx?ForumID=8&SiteID=1.
Have a great day!