遍历特定的控件属性c＃

Question

i need to iterate through a specific controls property and save the that control's property name & value in xml file. i wrote few line but getting error.

private void SaveStyle()
{
    XmlWriterSettings settings = new XmlWriterSettings();
    settings.Indent = true;
    XmlWriter writer = XmlWriter.Create(Application.ExecutablePath+ @"\Products.xml", settings);

    PropertyInfo[] properties = metroStyleManager1.GetType().GetProperties();
    writer.WriteStartDocument();
    foreach (PropertyInfo pi in properties)
    {
        writer.WriteElementString(pi.Name,pi.GetValue(((object)metroStyleManager1),null));
    }
}

this line is giving error writer.WriteElementString(pi.Name,pi.GetValue(((object)metroStyleManager1),null));

next issue which i need to do that i have to read back the controls property data from xml file and set the value as per the controls name. which is not clear to me that how to do it. so please help. thanks

UPDATE

my full code to save controls property & read back too.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Xml;
using MetroFramework;
namespace CSRAssistant
{
    class Utils
    {
        public static void SaveProperty(System.ComponentModel.Component _Control)
        {
            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Indent = true;
            XmlWriter writer = XmlWriter.Create(System.IO.Path.GetDirectoryName(System.Windows.Forms.Application.ExecutablePath) + @"\Products.xml", settings);

            PropertyInfo[] properties = _Control.GetType().GetProperties();
            writer.WriteStartElement("metroStyleManager");
            foreach (PropertyInfo pi in properties)
            {
                writer.WriteElementString(pi.Name, Convert.ToString(pi.GetValue(_Control, null)));
            }
            writer.WriteEndDocument();

            writer.Flush();
            writer.Close();
        }

       public static void ReadProperty(System.ComponentModel.Component _Control)
    {
        string _property = "", _value = "";
        if (System.IO.File.Exists(System.IO.Path.GetDirectoryName(System.Windows.Forms.Application.ExecutablePath) + @"\Products.xml"))
        {
            XmlReader rdr = XmlReader.Create(System.IO.Path.GetDirectoryName(System.Windows.Forms.Application.ExecutablePath) + @"\Products.xml");
            while (rdr.Read())
            {
                if (rdr.NodeType == XmlNodeType.Element)
                {
                    if (rdr.LocalName.ToUpper() != "METROSTYLEMANAGER")
                    {
                        _property = rdr.LocalName;
                        _value = rdr.ReadInnerXml();
                        if (_property.ToUpper() == "STYLE")
                            ((MetroFramework.Components.MetroStyleManager)_Control).Style = (MetroColorStyle)Enum.Parse(typeof(MetroColorStyle), _value);
                        if (_property.ToUpper() == "THEME")
                            ((MetroFramework.Components.MetroStyleManager)_Control).Theme = (MetroThemeStyle)Enum.Parse(typeof(MetroThemeStyle), _value);
                        //else
                        //    _Control.GetType().GetProperty(_property).SetValue(_Control, _value, null);
                    }
                }
            }

            rdr.Close();
        }
    }

    }
}

Answer 1

writer.WriteElementString(string localName, string value)

expects two string arguments. But pi.GetValue() returns value of type object . You need to convert second parameter to string:

Convert.ToString(pi.GetValue(metroStyleManager1))

That will check if value of object is not null, and return empty string if value is null. It also will check if object implements IConvertible or IFormattable interfaces and call appropriate ToString() method.

Answer 2

The exact error would surely help, but I guess your problem is the WriteElementString method which takes two string parameters.

PropertyInfo.GetValue on the other hand returns an object. You have to convert that object to a string . A possible way would be to call .ToString() on it if it's not null and use an empty string if it is.

---

foreach (PropertyInfo pi in properties)
{
    object obj = pi.GetValue(metroStyleManager1, null);                      
    writer.WriteElementString(pi.Name, obj != null ? obj.ToString() : String.Empty);
}