mes-client/UAS_MES_YD/CustomControl/TextBoxWithIcon/TextBoxWithPlaceHolder.cs

using System;
using System.Drawing;
using System.Windows.Forms;

namespace UAS_MES_NEW.CustomControl.TextBoxWithIcon
{
    public partial class TextBoxWithPlaceHolder : UserControl
    {
        //记录一个PlaceHolder，第一次对这个文本框赋的值
        string PlaceHolder1;

        public string PlaceHolder
        {
            get
            {
                return PlaceHolder1;
            }

            set
            {
                PlaceHolder1 = value;
            }
        }

        public override string Text
        {
            get
            {
                if (TextBox.Text == PlaceHolder1)
                {
                    return "";
                }
                return TextBox.Text;
            }

            set
            {
                TextBox.Text = value;
            }
        }

        public delegate void OnTextChange(object sender, EventArgs e);

        public event OnTextChange UserControlTextChanged;

        public TextBoxWithPlaceHolder()
        {
            InitializeComponent();
            Load += TextBoxWithPlaceHolder_Load;
        }

        private void TextBoxWithPlaceHolder_Load(object sender, System.EventArgs e)
        {
            TextBox.Text = PlaceHolder1;
            TextBox.ForeColor = Color.Silver;
        }

        private void TextBox_Leave(object sender, System.EventArgs e)
        {
            //失去焦点的时候如果文本框存在内容就把文字变色
            TextBox.BackColor = Color.White;
            if (TextBox.Text == "")
            {
                TextBox.ForeColor = Color.Silver;
                TextBox.Text = PlaceHolder1;
            }
        }

        private void TextBox_Enter(object sender, System.EventArgs e)
        {
            TextBox.ForeColor = Color.Black;
            if (TextBox.Text == PlaceHolder1)
            {
                TextBox.Text = "";
            }
            else TextBox.ForeColor = Color.Black;
        }

        private void TextBox_TextChanged(object sender, EventArgs e)
        {
            UserControlTextChanged?.Invoke(sender, new EventArgs());
        }
    }
}