DefaultAttribute not working in PropertyGrid on runtime generated

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Hi All,

I am testing some stuff out at the moment with the runtime generation of
classes relating to schema-validated XML elements. I was hoping to get to the
point that I could include the use of the DefaultValueAttribute on any
property that requires it. The PropertyGrid was then to be used to display
the various properties for editing but, this DefaultValueAttribute doesn't
seem to stick enough for the PropertyGrid to correctly bold/unbold values
entered.

EXAMPLE:

private static void _addAttribute(TypeBuilder tb, string PropertyName)
{
FieldBuilder fb = tb.DefineField("_" + PropertyName, typeof(string),
FieldAttributes.Private);

PropertyBuilder pb = tb.DefineProperty(PropertyName,
PropertyAttributes.HasDefault, typeof(string), new Type[] { typeof(string) });

Type t = typeof(System.ComponentModel.CategoryAttribute);

ConstructorInfo ci = t.GetConstructor(new Type[1]{typeof(string)});
CustomAttributeBuilder cab = new CustomAttributeBuilder(ci, new
string[1]{PropertyName});

pb.SetCustomAttribute(cab);

if (PropertyName == "CustomerName")
{
t = typeof(System.ComponentModel.DefaultValueAttribute);

ci = t.GetConstructor(new Type[1]{typeof(string)});
cab = new CustomAttributeBuilder(ci, new string[1]{"Robert Magnusson"});

pb.SetCustomAttribute(cab);
}

// First, we'll define the behavior of the "get" property for CustomerName
as a method.
MethodBuilder mbGet = tb.DefineMethod("Get" + PropertyName,
MethodAttributes.Public, typeof(string), new Type[] { });

ILGenerator custNameGetIL = mbGet.GetILGenerator();

custNameGetIL.Emit(OpCodes.Ldarg_0);
custNameGetIL.Emit(OpCodes.Ldfld, fb);
custNameGetIL.Emit(OpCodes.Ret);

// Now, we'll define the behavior of the "set" property for CustomerName.
MethodBuilder mbSet = tb.DefineMethod("Set" + PropertyName,
MethodAttributes.Public, null, new Type[] { typeof(string) });

ILGenerator custNameSetIL = mbSet.GetILGenerator();

custNameSetIL.Emit(OpCodes.Ldarg_0);
custNameSetIL.Emit(OpCodes.Ldarg_1);
custNameSetIL.Emit(OpCodes.Stfld, fb);
custNameSetIL.Emit(OpCodes.Ret);

// Last, we must map the two methods created above to our PropertyBuilder
to
// their corresponding behaviors, "get" and "set" respectively.
pb.SetGetMethod(mbGet);
pb.SetSetMethod(mbSet);
}
 
You say that it doesn't correctly bold/unbold values.
Which is it (alwyas bold or always normal)?
Is Reset enabled or disabled?

What does your generated code look like?

Have you intialized the property to its default value?
Just providing the the attribute isn't enough

/claes
 
Claes,
What does your generated code look like?
Click to expand...
How can I see it?
Which is it (alwyas bold or always normal)?
Click to expand...
It always stays bold. I have added the SetConstant call as below but I
don't see any difference to what's happening.

FieldBuilder fb = tb.DefineField("_" + PropertyName, typeof(string),
(PropertyName == "CustomerName" ? FieldAttributes.Private |
FieldAttributes.HasDefault : FieldAttributes.Private));

fb.SetConstant(@"Robert Magnusson");

Thanks for your help...

Claes Bergefall said:
You say that it doesn't correctly bold/unbold values.
Which is it (alwyas bold or always normal)?
Is Reset enabled or disabled?

What does your generated code look like?

Have you intialized the property to its default value?
Just providing the the attribute isn't enough

/claes

Robert Magnusson said:
Hi All,

I am testing some stuff out at the moment with the runtime generation of
classes relating to schema-validated XML elements. I was hoping to get to the
point that I could include the use of the DefaultValueAttribute on any
property that requires it. The PropertyGrid was then to be used to display
the various properties for editing but, this DefaultValueAttribute doesn't
seem to stick enough for the PropertyGrid to correctly bold/unbold values
entered.

EXAMPLE:

private static void _addAttribute(TypeBuilder tb, string PropertyName)
{
FieldBuilder fb = tb.DefineField("_" + PropertyName, typeof(string),
FieldAttributes.Private);

PropertyBuilder pb = tb.DefineProperty(PropertyName,
PropertyAttributes.HasDefault, typeof(string), new Type[] { typeof(string) });

Type t = typeof(System.ComponentModel.CategoryAttribute);

ConstructorInfo ci = t.GetConstructor(new Type[1]{typeof(string)});
CustomAttributeBuilder cab = new CustomAttributeBuilder(ci, new
string[1]{PropertyName});

pb.SetCustomAttribute(cab);

if (PropertyName == "CustomerName")
{
t = typeof(System.ComponentModel.DefaultValueAttribute);

ci = t.GetConstructor(new Type[1]{typeof(string)});
cab = new CustomAttributeBuilder(ci, new string[1]{"Robert Magnusson"});

pb.SetCustomAttribute(cab);
}

// First, we'll define the behavior of the "get" property for CustomerName
as a method.
MethodBuilder mbGet = tb.DefineMethod("Get" + PropertyName,
MethodAttributes.Public, typeof(string), new Type[] { });

ILGenerator custNameGetIL = mbGet.GetILGenerator();

custNameGetIL.Emit(OpCodes.Ldarg_0);
custNameGetIL.Emit(OpCodes.Ldfld, fb);
custNameGetIL.Emit(OpCodes.Ret);

// Now, we'll define the behavior of the "set" property for CustomerName.
MethodBuilder mbSet = tb.DefineMethod("Set" + PropertyName,
MethodAttributes.Public, null, new Type[] { typeof(string) });

ILGenerator custNameSetIL = mbSet.GetILGenerator();

custNameSetIL.Emit(OpCodes.Ldarg_0);
custNameSetIL.Emit(OpCodes.Ldarg_1);
custNameSetIL.Emit(OpCodes.Stfld, fb);
custNameSetIL.Emit(OpCodes.Ret);

// Last, we must map the two methods created above to our PropertyBuilder
to
// their corresponding behaviors, "get" and "set" respectively.
pb.SetGetMethod(mbGet);
pb.SetSetMethod(mbSet);
}
Click to expand...
Click to expand...
 
Robert Magnusson said:
Claes,

How can I see it?
Click to expand...

I don't know. I was hoping you could tell me :-)
Isn't there some kind of persisted ouput you can look at
(perhaps some dll that you can decompile)?
Perhaps you could save it to a file somehow.

It always stays bold. I have added the SetConstant call as below but I
don't see any difference to what's happening.

FieldBuilder fb = tb.DefineField("_" + PropertyName, typeof(string),
(PropertyName == "CustomerName" ? FieldAttributes.Private |
FieldAttributes.HasDefault : FieldAttributes.Private));

fb.SetConstant(@"Robert Magnusson");
Click to expand...

There is a SetValue method in the FieldBuilder class aswell.
Have you tried that? I don't really know what the difference
is but it's worth trying.

/claes
 
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