C# 中errorProvider控件的使用 和 正规表达式的使用

string strErrorMes = null;

if(Validates())
{
  XXXXX
}
 public bool Validates()
        {
            if (this.txtUserName.Text == "")
            {
                strErrorMes = "姓名不能为空！";
                this.txtUserName.Focus();
                errorProvider.SetError(this.txtUserName, strErrorMes); //给errorProvider控件赋值
            }
            if (this.txtNativePlace.Text == "")
            {
                strErrorMes = "籍贯不能为空！";
                this.txtNativePlace.Focus();
                errorProvider.SetError(this.txtNativePlace, strErrorMes); //给errorProvider控件赋值
            }
            if (this.txtphone.Text == "")
            {
                strErrorMes = "电话不能为空！";
                this.txtphone.Focus();
                errorProvider.SetError(this.txtphone, strErrorMes); //给errorProvider控件赋值
            }
            else
            {
                string regStr = @"((\d{11})|^((\d{7,8})|(\d{4}|\d{3})-(\d{7,8})|(\d{4}|\d{3})-(\d{7,8})-(\d{4}|\d{3}|\d{2}|\d{1})|(\d{7,8})-(\d{4}|\d{3}|\d{2}|\d{1}))$)";
                bool isRightNo = Regex.IsMatch(txtphone.Text.Trim(), regStr);
                if (!isRightNo)
                {
                    strErrorMes = "电话格式错误";
                    txtphone.Focus();
                    errorProvider.SetError(txtphone, strErrorMes);
                }
            }
            if (strErrorMes != null)
            {

              strErrorMes = null;

              return false;

            }
            return true;
        }