WPF手写代码配置文件——单例

   public class SettingHelper
    {
        //WPF下配置文件路径
        public static readonly string SettingFilePath = AppDomain.CurrentDomain.BaseDirectory + "\\Setting.ini";
        
        private static class Instance
        {
            internal static readonly SettingHelper Setting = new SettingHelper();
        }

        private SettingHelper() { }

        public static SettingHelper GetInstance()
        {
            return Instance.Setting;
        }

        #region API函数声明

        [DllImport("kernel32")]//返回0表示失败，非0为成功
        private static extern long WritePrivateProfileString(string section, string key, string val, string filePath);

        [DllImport("kernel32")]//返回取得字符串缓冲区的长度
        private static extern long GetPrivateProfileString(string section, string key, string def, StringBuilder retVal, int size, string filePath);

        #endregion


        #region 读Ini文件

        public string ReadIniData(string section, string key)
        {
            return ReadIniData(section, key, string.Empty);
        }

        public string ReadIniData(string section, string key, string defaultValue)
        {
            if (File.Exists(SettingFilePath))
            {
                StringBuilder s = new StringBuilder(1024);

                GetPrivateProfileString(section, key, defaultValue, s, 1024, SettingFilePath);

                return s.ToString();
            }
            else
            {
                return String.Empty;
            }
        }

        #endregion

        public bool WriteIniData(string section, string key, string value)
        {
            if (File.Exists(SettingFilePath))
            {
                long OpStation = WritePrivateProfileString(section, key, value, SettingFilePath);

                if (OpStation == 0)
                {
                    return false;
                }
                else
                {
                    return true;
                }
            }
            else
            {
                return false;
            }
        }

        private string windowState;

        public WindowState WindowState
        {
            get
            {
                if (string.IsNullOrWhiteSpace(windowState))
                {
                    SettingHelper st = SettingHelper.GetInstance();

                    windowState = st.ReadIniData("WPF", "WindowState");
                }

                if (string.IsNullOrWhiteSpace(windowState))
                {
                    windowState = ((int)System.Windows.WindowState.Normal).ToString();
                }

                return (WindowState)Convert.ToInt32(windowState);
            }

            set
            {
                windowState = ((int)value).ToString();

                SettingHelper st = SettingHelper.GetInstance();

                st.WriteIniData("WPF", "WindowState", windowState);
            }
        }

        private string left;

        public double Left
        {
            get
            {
                if (string.IsNullOrWhiteSpace(left))
                {
                    SettingHelper st = SettingHelper.GetInstance();

                    left = st.ReadIniData("WPF", "Left");
                }

                if (string.IsNullOrWhiteSpace(left))
                {
                    left = "20";
                }

                return Convert.ToDouble(left);
            }

            set
            {
                left = value.ToString();

                SettingHelper st = SettingHelper.GetInstance();

                st.WriteIniData("WPF", "Left", left);
            }
        }

        private string top;

        public double Top
        {
            get
            {
                if (string.IsNullOrWhiteSpace(top))
                {
                    SettingHelper st = SettingHelper.GetInstance();

                    top = st.ReadIniData("WPF", "Top");
                }

                if (string.IsNullOrWhiteSpace(top))
                {
                    top = "20";
                }

                return Convert.ToDouble(top);
            }

            set
            {
                top = value.ToString();

                SettingHelper st = SettingHelper.GetInstance();

                st.WriteIniData("WPF", "Top", top);
            }
        }
    }