查找button的子元素是个TextBlock,再设置它的TextWrappingProperty属性为 TextWrapping.Wrap。

 

  Button btn2 = new Button() {Content="fdhfhfhfhfghfhfhfhfhhfh",Width=88};
            btn2.Loaded += Btn2_Loaded;
            gridRoot.Children.Add(btn2);


        }

        private void Btn2_Loaded(object sender, RoutedEventArgs e)
        {
            Button btn = (sender as Button);
            var o = GetChildObjects<TextBlock>(btn, typeof(TextBlock));
            o[0].SetValue(TextBlock.TextWrappingProperty, TextWrapping.Wrap);

        }

      

        /// <summary>
        /// 根据类型查找子元素
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="obj"></param>
        /// <param name="typename"></param>
        /// <returns></returns>
        public List<T> GetChildObjects<T>(DependencyObject obj, Type typename) where T : FrameworkElement
        {
            DependencyObject child = null;
            List<T> childList = new List<T>();

            for (int i = 0; i <= VisualTreeHelper.GetChildrenCount(obj) - 1; i++)
            {
                child = VisualTreeHelper.GetChild(obj, i);

                if (child is T && (((T)child).GetType() == typename))
                {
                    childList.Add((T)child);
                }
                childList.AddRange(GetChildObjects<T>(child, typename));
            }
            return childList;
        }

  

fffffffffffffffff
test red font.