HTML เบื้องต้น

ไฟล์ html

<!DOCTYPE html>
<html>

<head>
    <title>Page Title</title>
</head>

<body>

    <h1>This is a Heading</h1>
    <p>This is a paragraph.</p>

</body>

</html>

ไฟล์ html + Bootstrap 4

<!doctype html>
<html lang="en">

<head>
    <!-- Required meta tags -->
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

    <!-- Bootstrap CSS -->
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css"
        integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">

    <title>Hello, world!</title>
</head>

<body>
    <h1>Hello, world!</h1>

    <!-- Optional JavaScript -->
    <!-- jQuery first, then Popper.js, then Bootstrap JS -->
    <script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"
        integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n"
        crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"
        integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo"
        crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"
        integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6"
        crossorigin="anonymous"></script>
</body>

</html>

bootstrap 4 มี header ตรงกลาง และมี 3 คอลัมน์

<!doctype html>
<html lang="en">

<head>
    <!-- Required meta tags -->
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

    <!-- Bootstrap CSS -->
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css"
        integrity="sha384-Vkoo8x4CGsO3+Hhxv8T/Q5PaXtkKtu6ug5TOeNV6gBiFeWPGFN9MuhOf23Q9Ifjh" crossorigin="anonymous">

    <title>Hello, world!</title>
</head>

<body>
    <div class="jumbotron text-center">
        <h1>Hello, world!</h1>
        <p>Resize this responsive page to see the effect!</p>
    </div>

    <div class="container">
        <div class="row">
            <div class="col-sm-4">
                <h3>Column 1</h3>
                <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit...</p>
                <p>Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris...</p>
            </div>
            <div class="col-sm-4">
                <h3>Column 2</h3>
                <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit...</p>
                <p>Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris...</p>
            </div>
            <div class="col-sm-4">
                <h3>Column 3</h3>
                <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit...</p>
                <p>Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris...</p>
            </div>
        </div>
    </div>
    <!-- Optional JavaScript -->
    <!-- jQuery first, then Popper.js, then Bootstrap JS -->
    <script src="https://code.jquery.com/jquery-3.4.1.slim.min.js"
        integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n"
        crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js"
        integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo"
        crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"
        integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6"
        crossorigin="anonymous"></script>
</body>

</html>

C# Base64

นำสตริง 111 มาทำเป็น Base64 แล้ว ถอดกลับออกมา

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string plainText1 = "111";
            byte[] byteData1 = System.Text.ASCIIEncoding.ASCII.GetBytes(plainText1);
            string encodeText = System.Convert.ToBase64String(byteData1);
            Console.WriteLine(encodeText);

            byte[] byteData2 = System.Convert.FromBase64String(encodeText);
            string plainText2 = System.Text.ASCIIEncoding.ASCII.GetString(byteData2);
            Console.WriteLine(plainText2);
        }
    }
}

// MTEx
// 111

Dataset

โปรเจ็กส์แบบ Web ใช้คำสั่ง Field แล้วได้ Error

DataRow row0 = dt.Rows[0];
DateTime createDate = row0.Field<DateTime>("createdate");
'System.Data.DataRow' does not contain a definition for 'Field' and no extension method 'Field' accepting a first argument of type 'System.Data.DataRow' could be found (are you missing a using directive or an assembly reference?)

ทางแก้ ให้ติดตั้ง System.Data.DataSetExtensions

PM> Install-Package System.Data.DataSetExtensions
Posted in C#