后台添加Textbox

         /// <summary>
         /// behind add textbox
         /// </summary>
         private void AddTextToTextBox()
         {
             TextBlock tb = new TextBlock();
             tb.TextWrapping = TextWrapping.Wrap;
             tb.Margin = new Thickness();
             tb.Inlines.Add("An example on ");
             tb.Inlines.Add(new Run("the TextBlock control ") { FontWeight = FontWeights.Bold });
             tb.Inlines.Add("using ");
             tb.Inlines.Add(new Run("inline ") { FontStyle = FontStyles.Italic });
             tb.Inlines.Add(new Run("text formatting ") { Foreground = Brushes.Blue });
             tb.Inlines.Add("from ");
             tb.Inlines.Add(new Run("Code-Behind") { TextDecorations = TextDecorations.Underline });
             tb.Inlines.Add(".");
             this.sp_text.Children.Add(tb);
         }