A bug bound to itemssource of WPF itemscontrol

I don't know whether it is a bug or something. I encountered this problem.

I tested it. All itemscontrols sub-classes have this problem. For example: ComboBox

Public class namevalue
{
Public object value {Get; set ;}
Public string name {Get; set ;}
}

Public class testobj: inotifypropertychanged

{

Public event propertychangedeventhandler propertychanged;
Protected void notify (string propname)
{
If (this. propertychanged! = NULL)
{
Propertychanged (this, new propertychangedeventargs (propname ));
}
}

Int _ V1;
Public int V1 {

Get {return _ V1 ;}

Set {

If (this. _ V1 = value) {return ;}
This. _ V1 = value;
Y ("V1 ");

}

}

Int _ V2;
Public int V2 {

Get {return _ V2 ;}

Set {

If (this. _ v2 = value) {return ;}
This. _ v2 = value;
Y ("V2 ");

}

}

}

Initialize list

List <namevalue> lst = new list <namevalue> ();

Lst. Add (New namevalue () {name = "Item1", value = "1 "});

Lst. Add (New namevalue () {name = "item2", value = "2 "});

Lst. Add (New namevalue () {name = "item3", value = "3 "});

Bind to ComboBox

Cbo1.itemssource = lst;

Cbo2.itemssource = lst;

DataGrid. datacontext = new testobj (){

V1 = 1,

V2 = 2

};

XAMLCode

<Grid X: Name = "DataGrid">

<ComboBox X: name = "cbo1" displaymemberpath = "name" selectedvaluepath = "value" width = "80" issynchronizedwithcurrentitem = "true" selectedvalue = "{binding Path = V1}"/>

<ComboBox X: name = "cbo2" displaymemberpath = "name" selectedvaluepath = "value" width = "80" issynchronizedwithcurrentitem = "true" selectedvalue = "{binding Path = v2}"/>

</GRID>

Test. The result is that cbo1 and cbo2 are linked.

 

Solution

Cbo1.itemssource = lst. toarray ();

Cbo2.itemssource = lst. toarray ();

DataGrid. datacontext = new testobj (){

V1 = 1,

V2 = 2

};

Itemssource points to the same list, causing select synchronization. The toarray () method actually clones two namevalue array instances, so that select synchronization is not generated.