遍历文本框

若要递归获取所有指定类型的控件和子控件，请使用以下扩展方法：

public static IEnumerable<TControl> GetChildControls<TControl>(this Control control) where TControl : Control{    var children = (control.Controls != null) ? control.Controls.OfType<TControl>() : Enumerable.Empty<TControl>();    return children.SelectMany(c => GetChildControls<TControl>(c)).Concat(children);}

用法：

var allTextBoxes = this.GetChildControls<TextBox>();foreach (TextBox tb in allTextBoxes){    tb.Text = ...;}