到目前为止，我想到的是这样的：

public static class extenstions
{
    private static Dictionary<Type, Action<Control>> controldefaults = new Dictionary<Type, Action<Control>>() { 
            {typeof(TextBox), c => ((TextBox)c).Clear()},
            {typeof(CheckBox), c => ((CheckBox)c).Checked = false},
            {typeof(ListBox), c => ((ListBox)c).Items.Clear()},
            {typeof(RadioButton), c => ((RadioButton)c).Checked = false},
            {typeof(GroupBox), c => ((GroupBox)c).Controls.ClearControls()},
            {typeof(Panel), c => ((Panel)c).Controls.ClearControls()}
    };

    private static void FindAndInvoke(Type type, Control control) 
    {
        if (controldefaults.ContainsKey(type)) {
            controldefaults[type].Invoke(control);
        }
    }

    public static void ClearControls(this Control.ControlCollection controls)
    {
        foreach (Control control in controls)
        {
             FindAndInvoke(control.GetType(), control);
        }
    }

    public static void ClearControls<T>(this Control.ControlCollection controls) where T : class 
    {
        if (!controldefaults.ContainsKey(typeof(T))) return;

        foreach (Control control in controls)
        {
           if (control.GetType().Equals(typeof(T)))
           {
               FindAndInvoke(typeof(T), control);
           }
        }

    }

}

现在，您可以像这样调用扩展方法ClearControls：

 private void button1_Click(object sender, EventArgs e)
    {
        this.Controls.ClearControls();
    }

编辑：我刚刚添加了一个通用的ClearControls方法，该方法将清除该类型的所有控件，可以这样调用：

this.Controls.ClearControls<TextBox>();

目前，它将仅处理顶级控件，而不会深入研究组框和面板。