How to bind MinWidth of DatagridTemplateColumn

Question

Good morning,

 

 I am using a datagrid which contain 3 columns. The second columns contains text from a observable collection. I would like to bind the "MinWidth" property of the column with the size of a text of the observable collection. Actually I would like to have the "MinWitdh" equals to the number of characters of the largest text. I created a mechanism to do that and it is working when I bind the property "Width" but not with "MinWidth" and I don't know why so if someone has an idea.

 

Thanks in advance.