如何清除Asp.Net按钮上所有文本框的值单击

我有一个按钮来显示有关客户的记录或信息,我刚刚注意到的问题是,当我选择提供所有必要信息的客户时,有关该特定客户的信息显示正确,现在当我尝试显示其他客户时有一些缺少字段的信息,那个时候这个特定客户的缺失字段被以前的客户信息所取代,这意味着我需要一种方法来清除文本框,然后才显示客户信息.这是我必须显示的方法信息.

public void ShowCustomerInformationCat1()
        {
            if (customer.cCustomerType != null)
            {
                ModifyCustomerByCategoryddlCustomerType.SelectedIndex = ModifyCustomerByCategoryddlCustomerType.Items.IndexOf(ModifyCustomerByCategoryddlCustomerType.Items.FindByText(customer.cCustomerType.Trim()));
                ModifyCustomerByCategoryddlNewCustomerType.SelectedIndex = ModifyCustomerByCategoryddlNewCustomerType.Items.IndexOf(ModifyCustomerByCategoryddlNewCustomerType.Items.FindByText(customer.cCustomerType.Trim()));
            }
            if (customer.cInitial != null)
            {
                ModifyCustomerByCategoryddlInitial.SelectedIndex = ModifyCustomerByCategoryddlInitial.Items.IndexOf(ModifyCustomerByCategoryddlInitial.Items.FindByText(customer.cInitial.Trim()));
                ModifyCustomerByCategoryddlNewInitial.SelectedIndex = ModifyCustomerByCategoryddlNewInitial.Items.IndexOf(ModifyCustomerByCategoryddlNewInitial.Items.FindByText(customer.cInitial.Trim()));
            }
            if (customer.cGender != null)
            {
                ModifyCustomerByCategoryddlGender.SelectedIndex = ModifyCustomerByCategoryddlGender.Items.IndexOf(ModifyCustomerByCategoryddlGender.Items.FindByText(customer.cGender.Trim()));
                ModifyCustomerByCategoryddlNewGender.SelectedIndex = ModifyCustomerByCategoryddlNewGender.Items.IndexOf(ModifyCustomerByCategoryddlNewGender.Items.FindByText(customer.cGender.Trim()));
            }
            if (customer.cCountry != null)
            {
                ModifyCustomerByCategoryddlCountry.SelectedIndex = ModifyCustomerByCategoryddlCountry.Items.IndexOf(ModifyCustomerByCategoryddlCountry.Items.FindByText(customer.cCountry.Trim()));
                ModifyCustomerByCategoryddlNewCountry.SelectedIndex = ModifyCustomerByCategoryddlNewCountry.Items.IndexOf(ModifyCustomerByCategoryddlNewCountry.Items.FindByText(customer.cCountry.Trim()));
            }
}

任何人都可以建议我如何清除文本框,我不想单独清除它们.
谢谢你的任何建议.

foreach (var item in Page.Controls)
        {
            if (item is TextBox)
            {
                ((TextBox)item).Text = "";
            }
        }