Set value to FontDialog in WPF
===

I am working on WPF with text. Now I want to edit text using FontDialog but I cannot set current style of text to FontDialog so the style of text change everytime I call FontDialog. Can you guys help me?

This my code:

    System.Windows.Forms.FontDialog fontDialog = new System.Windows.Forms.FontDialog();
            if (fontDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                this.textAnnotation.Font.Size = fontDialog.Font.Size;
                this.textAnnotation.Font.Name = fontDialog.Font.Name;
                this.textAnnotation.Font.Underline = fontDialog.Font.Underline;
                this.textAnnotation.Font.Strikeout = fontDialog.Font.Strikeout;
                this.textAnnotation.Font.Bold = fontDialog.Font.Bold;
                this.textAnnotation.Font.Italic = fontDialog.Font.Italic;
            }


