Placeholder Winforms

Placeholder.cs

        class InternalTextBox : MaskedTextBox
        {
            bool _PlaceholderHandled = false;
            void DoPlaceholder()
            {



                if (Placeholder.Length > 0 && this.Text == string.Empty && this.Text != this.Placeholder)
                {
                    this.Text = Placeholder;
                    this.ForeColor = Color.Gray;
                }
                if (!_PlaceholderHandled)
                {
                    _PlaceholderHandled = true;
                    this.Leave += (object sender, EventArgs e) => {
                        DoPlaceholder();
                    };
                    this.Click += (object sender, EventArgs e) => {
                        this.Text = string.Empty;
                        this.ForeColor = Color.Black;
                    };
                }

            }

            string _Placeholder = "";
            public string Placeholder
            {

                get
                {
                    return _Placeholder;
                }
                set
                {
                    this._Placeholder = value;
                    DoPlaceholder();
                }
            }
        }