WPF 查找ListBox等DataTemplate下的子控件

做项目时找到的方法，引用自http://bbs.csdn.net/topics/390890082，觉得挺好的，保存下来

获取在ListBox中的DataTemplate下的每一个button对象的方法如下：
 private T SearchVisualTree<T>(DependencyObject tarElem) where T : DependencyObject
        {
            if (tarElem != null)
            {
                var count = VisualTreeHelper.GetChildrenCount(tarElem);
                if (count == 0)
                    return null;
                for (int i = 0; i < count; ++i)
                {
                    var child = VisualTreeHelper.GetChild(tarElem, i);
                    if (child != null && child is T)
                    {
                        return (T)child;
                    }
                    else
                    {
                        var res = SearchVisualTree<T>(child);
                        if (res != null)
                        {
                            return res;
                        }
                    }
                }
                return null;
            }
   private void GetBtn()
        {
            for (int i = 0; i < this.ListBoxName.Items.Count; i++)
            {
                ListBoxItem itemtemp = this.ListBoxName.ItemContainerGenerator.ContainerFromIndex(i) as ListBoxItem;
                Button buttonobject = SearchVisualTree<Button>(itemtemp);
                if (buttonobject == null) break;
               buttonobject.Margin = new Thickness(10, 10, 10, 10);
            }
        }

原文：http://www.cnblogs.com/Liang-Xiang/p/7728017.html