??? ??? ?? ??? ??? ??

??? ???? ?? ??? ???? ???? ?? ? ??? ???? ???? ?? ????? ???? ???? ???? ? ??? ???. ???? ???????? ? ??? ??????? ?? ??? ??? ??? ??? ???? ??? ? ????.

.NET??? ??? ?? ??? '???' ??? ?? ??? ???? ???? ? ??? ??? ? ????. . ???? ??? ??? ??? ?? ?? ?? ????? ??? 'GotFocus' ? 'LostFocus' ???? ??? ? ????.

??? ??? ???? ??? 'GotFocus' ???? ??????. ??? ????? ?? ???? ????? ???? ????? ?????. ???? ???? ?????. ? ??? ???? ????? ???? ????? ???? ???? ??? ???? ??? ? ????.

???, ??? ??? ???? ??? 'LostFocus' ???? ?????. ??? ????? ???? ?? ??? ?? ????? ???? ??? ??????. ? ?? ?? ??? ???? ??? ??? ?? ???? ?? ????? ?????.

??? ??? ???? ?? ?? ?????.

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

public class Form1 : Form
{
    private TextBox myTextBox;

    public Form1()
    {
        myTextBox = new TextBox();
        // Set the placeholder text
        myTextBox.Text = "Enter text here...";

        // Add event handlers for focus events
        myTextBox.GotFocus += TextBox_GotFocus;
        myTextBox.LostFocus += TextBox_LostFocus;

        Controls.Add(myTextBox);
    }

    private void TextBox_GotFocus(object sender, EventArgs e)
    {
        // Check if the text is placeholder text
        if (myTextBox.Text == "Enter text here...")
        {
            // Clear the text
            myTextBox.Text = "";
        }
    }

    private void TextBox_LostFocus(object sender, EventArgs e)
    {
        // Check if the text is empty or whitespace
        if (string.IsNullOrWhiteSpace(myTextBox.Text))
        {
            // Add the placeholder text back
            myTextBox.Text = "Enter text here...";
        }
    }
}

??? ??? ???? ???? HTML5? ?? ??? ??? ??? ??? ???? ??? ???? ?? ??? ???? ???? ?? ? ??? ? ????.

? ??? .NET TextBox?? ?? ??? ???? ???? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!