本示例使用设备：https://item.taobao.com/item.htm?spm=a21dvs.23580594.0.0.52de2c1b5P5rkA&ft=t&id=22173428704

[DllImport("kernel32", CharSet = CharSet.Unicode)]
public static extern uint GetPrivateProfileString(string lpAppName, string lpKeyName, string lpDefault, StringBuilder lpReturnedString, uint nSize, string lpFileName);

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
public static extern long WritePrivateProfileString(string section, string key, string val, string filePath);

public static string sGetINI(string strPath, string strSection, string strKey, string strDefault) {
    StringBuilder returnString = new StringBuilder(255);  // 返回值存储区
    uint bufferSize = (uint)returnString.Capacity;
    uint result = GetPrivateProfileString(strSection, strKey, strDefault, returnString, bufferSize, strPath);
    return returnString.ToString();
}

private void Form20_Load(object sender, EventArgs e){
    textBox26.Text = sGetINI("./syssetup.ini", "DefaultSetup", "HttpAccessFile", "IC-14.asp");
    comboBox13.SelectedIndex = int.Parse(sGetINI("./syssetup.ini", "DefaultSetup", "HttpAccessMode", "0"));
    WebPort.Value = int.Parse(sGetINI("./syssetup.ini", "DefaultSetup", "HttpAccessPort", "88"));
}

private void Form20_FormClosed(object sender, FormClosedEventArgs e) {
    WritePrivateProfileString("DefaultSetup", "HttpAccessFile", textBox26.Text，"./syssetup.ini");
    WritePrivateProfileString("DefaultSetup", "HttpAccessMode", comboBox13.SelectedIndex.ToString(),"./syssetup.ini");
    WritePrivateProfileString("DefaultSetup", "HttpAccessPort", WebPort.Value.ToString(),"./syssetup.ini");            
}