[C#} 如何 read/write app.config

對專案按滑鼠右鍵,選擇 Properties,選擇左邊的Tab的Settings,加入所需參數

選表單的Porject/Add Reference,加入 System.Configuration

範例:
using System.Configuration;


namespace AppConfigExample
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
            int num = Properties.Settings.Default.Num;
            textBox1.Text = Convert.ToString(num);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            int num = Convert.ToInt32(textBox1.Text);
            Properties.Settings.Default.Num=num;
            Properties.Settings.Default.Save();
        }
    }

}

不錯的文章:

http://wlchang1108.blogspot.tw/2016/08/visual-studioproertiessettingssettings.html

https://dotblogs.com.tw/yc421206/2010/08/08/17076