Get properties of class

use SQL When inserting or querying data in the form of script , Sometimes you need to list all the field names . And the way of using fixed code to write dead is undoubtedly not conducive to expansion . At this time, you can consider using reflection to obtain all the properties of the class , Then, the attribute names are spliced together to handle . Using return PropertyInfo Two of the arrays GetProperties Method , What needs to be noted is , Sometimes because of the framework or other reasons , You don't need to return all the attributes , It's time to take advantage of Linq Do some filtering .

Not much to say , Go straight to the code . Tool class and Class The class code is as follows ：

using System;
using System.Linq;
using System.Reflection;
using System.Text;

namespace WindowsFormsApp1
{
    public class RefelctHelper
    {
        public static string AllPublicFields<T>()
        {
            PropertyInfo[] propertyInfos = typeof(T).GetProperties();
            StringBuilder stringBuilder = new StringBuilder();
            foreach (PropertyInfo propertyInfo in propertyInfos)
            {
                stringBuilder.Append(propertyInfo.Name + ",");
            }
            string fields = stringBuilder.ToString();
            fields = fields.Substring(0, fields.LastIndexOf(','));
            return fields;
        }

        public static string WithoutVirtualFields<T>()
        {
            PropertyInfo[] propertyInfos = typeof(T).GetProperties().Where(x => !x.GetMethod.IsVirtual).ToArray();
            StringBuilder stringBuilder = new StringBuilder();
            foreach (PropertyInfo propertyInfo in propertyInfos)
            {
                stringBuilder.Append(propertyInfo.Name + ",");
            }
            string fields = stringBuilder.ToString();
            fields = fields.Substring(0, fields.LastIndexOf(','));
            return fields;
        }
    }

    public class HasVirtualProperties : NormalClass
    {
        public virtual Guid Id { get; set; }
    }
    public class HasNoSetProperties : NormalClass
    {
        public string Comment
        {
            get { return $"Name:{Name}Address:{Address}"; }
        }
    }
    public class NormalClass
    {
        public string Name { get; set; }
        public string Nation { get; set; }
        public string Address { get; set; }
    }
}

Call location code ：

Console.WriteLine($"Class {nameof(NormalClass)} Properties:{ RefelctHelper.AllPublicFields<NormalClass>()}");
Console.WriteLine($"Class {nameof(NormalClass)} Properties:{RefelctHelper.AllPublicFields<HasNoSetProperties>()}");
Console.WriteLine($"Class {nameof(NormalClass)} Properties:{RefelctHelper.AllPublicFields<HasVirtualProperties>()}");
Console.WriteLine($"Class {nameof(NormalClass)} Properties(excluded virtual properties):{RefelctHelper.WithoutVirtualFields<NormalClass>()}");
Console.WriteLine($"Class {nameof(NormalClass)} Properties(excluded virtual properties):{RefelctHelper.WithoutVirtualFields<HasNoSetProperties>()}");
Console.WriteLine($"Class {nameof(NormalClass)} Properties(excluded virtual properties):{RefelctHelper.WithoutVirtualFields<HasVirtualProperties>()}");

The output is as follows ：

take Name The access modifier is changed to protected、Nation The access modifier is changed to internal, Output is as follows ：

 

It's not hard to see. GetProperties() Method returns all the public properties of the class , Including the inheritance from the parent class 、 No, Set Attribute 、 Virtual attribute, etc . If you want to get all the attributes, you can use the following method ：

        public static string AllFields<T>()
        {
            PropertyInfo[] propertyInfos = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static);
            StringBuilder stringBuilder = new StringBuilder();
            foreach (PropertyInfo propertyInfo in propertyInfos)
            {
                stringBuilder.Append(propertyInfo.Name + ",");
            }
            string fields = stringBuilder.ToString();
            fields = fields.Substring(0, fields.LastIndexOf(','));
            return fields;
        }

You can use PropertyInfo Class MethodInfo Type of GetMethod Attribute to filter out the attributes that meet the needs .

Access modifier and attribute cross reference relationship

attribute	Access modifier
IsPublic	public
IsPrivate	private
IsFamily	protected
IsAssembly	internal
IsFamilyAndAssembly	C# I won't support it
IsFamilyOrAssembly	protected internal

 

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