mes-client/UAS-MES/CustomControl/TextBoxWithIcon/TextBoxWithPlaceHolder.cs

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

namespace UAS_MES.CustomControl.TextBoxWithIcon
{
    public partial class TextBoxWithPlaceHolder : EnterTextBox
    {
        //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 TextBoxWithPlaceHolder()
        {
            InitializeComponent();
            this.GotFocus += TextBoxWithPlaceHolder_GetFocus;
        }

        private void TextBoxWithPlaceHolder_GetFocus(object sender, System.EventArgs e) {

        }

        private void TextBoxWithPlaceHolder_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
            BackColor = Color.White;
            if (Text == "")
            {
                ForeColor = Color.Silver;
                Text = PlaceHolder1;
            }
        }

        private void TextBoxWithPlaceHolder_Enter(object sender, System.EventArgs e)
        {
            BackColor = Color.GreenYellow;
            ForeColor = Color.Black;
            //如果文本框的内容等与PlaceHolder就将文本框清空
            if (Text == PlaceHolder1)
            {
                Clear();
            }
        }

        private void textBox1_TextChanged(object sender, System.EventArgs e)
        {
            //由于PlaceHolder可能是在加载完窗体之后赋值，所以在TextChanged中再次判断
            if (PlaceHolder1 == "")
            {
                PlaceHolder1 = Text;
            }
        }
    }
}