Find a private field with Reflection

Question

Given this class  class Foo          Want to find  bar with reflection      SomeAttribute      private string  bar       public string BigBar               get   return this  bar              I want to find the private item  bar that I will mark with a attribute   Is that possible     I have done this with properties where I have looked for an attribute  but never a private member field   What are the binding flags that I need to set to get the private fields

User · Answer

typeof MyType  GetField  fieldName   BindingFlags NonPublic   BindingFlags Instance

User · Answer

Use BindingFlags NonPublic and BindingFlags Instance flags  FieldInfo   fields   myType GetFields                           BindingFlags NonPublic                             BindingFlags Instance

User · Answer

Yes  however you will need to set your Binding flags to search for private fields  if your looking for the member outside of the class instance    The binding flag you will need is  System Reflection BindingFlags NonPublic

User · Answer

One thing that you need to be aware of when reflecting on private members is that if your application is running in medium trust  as  for instance  when you are running on a shared hosting environment   it won t find them -- the BindingFlags NonPublic option will simply be ignored

User · Answer

Yes  however you will need to set your Binding flags to search for private fields  if your looking for the member outside of the class instance    The binding flag you will need is  System Reflection BindingFlags NonPublic

User · Answer

You can do it just like with a property   FieldInfo fi   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance   if  fi GetCustomAttributes typeof SomeAttribute      null

User · Answer

Yes  however you will need to set your Binding flags to search for private fields  if your looking for the member outside of the class instance    The binding flag you will need is  System Reflection BindingFlags NonPublic

User · Answer

One thing that you need to be aware of when reflecting on private members is that if your application is running in medium trust  as  for instance  when you are running on a shared hosting environment   it won t find them -- the BindingFlags NonPublic option will simply be ignored

User · Answer

Nice Syntax With Extension Method You can access any private field of an arbitrary type with code like this  Foo foo   new Foo    string c   foo GetFieldValue lt string gt   quot  bar quot     For that you need to define an extension method that will do the work for you  public static class ReflectionExtensions       public static T GetFieldValue lt T gt  this object obj  string name               Set the flags so that private and public fields from instances will be found         var bindingFlags   BindingFlags Public   BindingFlags NonPublic   BindingFlags Instance          var field   obj GetType   GetField name  bindingFlags           return  T field  GetValue obj

User · Answer

You can do it just like with a property   FieldInfo fi   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance   if  fi GetCustomAttributes typeof SomeAttribute      null

User · Answer

Here is some extension methods for simple get and set private fields and properties  properties with setter    usage example        public class Foo               private int Bar   5             var targetObject   new Foo        var barValue   targetObject GetMemberValue  Bar     Result is 5     targetObject SetMemberValue  Bar   10    Sets Bar to 10    Code            lt summary gt          Extensions methos for using reflection to get   set member values          lt  summary gt      public static class ReflectionExtensions                    lt summary gt              Gets the public or private member using reflection               lt  summary gt               lt param name  obj  gt The source target  lt  param gt               lt param name  memberName  gt Name of the field or property  lt  param gt               lt returns gt the value of member lt  returns gt          public static object GetMemberValue this object obj  string memberName                        var memInf   GetMemberInfo obj  memberName                if  memInf    null                  throw new System Exception  memberName                 if  memInf is System Reflection PropertyInfo                  return memInf As lt System Reflection PropertyInfo gt    GetValue obj  null                if  memInf is System Reflection FieldInfo                  return memInf As lt System Reflection FieldInfo gt    GetValue obj                throw new System Exception                            lt summary gt              Gets the public or private member using reflection               lt  summary gt               lt param name  obj  gt The target object  lt  param gt               lt param name  memberName  gt Name of the field or property  lt  param gt               lt returns gt Old Value lt  returns gt          public static object SetMemberValue this object obj  string memberName  object newValue                        var memInf   GetMemberInfo obj  memberName                 if  memInf    null                  throw new System Exception  memberName                 var oldValue   obj GetMemberValue memberName                if  memInf is System Reflection PropertyInfo                  memInf As lt System Reflection PropertyInfo gt    SetValue obj  newValue  null               else if  memInf is System Reflection FieldInfo                  memInf As lt System Reflection FieldInfo gt    SetValue obj  newValue               else                 throw new System Exception                 return oldValue                          lt summary gt              Gets the member info              lt  summary gt               lt param name  obj  gt source object lt  param gt               lt param name  memberName  gt name of member lt  param gt               lt returns gt instanse of MemberInfo corresponsing to member lt  returns gt          private static System Reflection MemberInfo GetMemberInfo object obj  string memberName                        var prps   new System Collections Generic List lt System Reflection PropertyInfo gt                  prps Add obj GetType   GetProperty memberName                                                 System Reflection BindingFlags NonPublic   System Reflection BindingFlags Public   System Reflection BindingFlags Instance                                                  System Reflection BindingFlags FlattenHierarchy                prps   System Linq Enumerable ToList System Linq Enumerable Where  prps i   gt   ReferenceEquals i  null                 if  prps Count    0                  return prps 0                var flds   new System Collections Generic List lt System Reflection FieldInfo gt                  flds Add obj GetType   GetField memberName                                              System Reflection BindingFlags NonPublic   System Reflection BindingFlags Instance                                               System Reflection BindingFlags FlattenHierarchy                   to add more types of properties              flds   System Linq Enumerable ToList System Linq Enumerable Where flds  i   gt   ReferenceEquals i  null                  if  flds Count    0                  return flds 0                return null                      System Diagnostics DebuggerHidden          private static T As lt T gt  this object obj                        return  T obj

User · Answer

I use this method personally  if  typeof Foo  GetFields BindingFlags NonPublic   BindingFlags Instance  Any c   gt  c GetCustomAttributes typeof SomeAttribute   false  Any               do stuff

User · Answer

Use BindingFlags NonPublic and BindingFlags Instance flags  FieldInfo   fields   myType GetFields                           BindingFlags NonPublic                             BindingFlags Instance

User · Answer

Use BindingFlags NonPublic and BindingFlags Instance flags  FieldInfo   fields   myType GetFields                           BindingFlags NonPublic                             BindingFlags Instance

User · Answer

You can do it just like with a property   FieldInfo fi   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance   if  fi GetCustomAttributes typeof SomeAttribute      null

User · Answer

Yes  however you will need to set your Binding flags to search for private fields  if your looking for the member outside of the class instance    The binding flag you will need is  System Reflection BindingFlags NonPublic

User · Answer

I use this method personally  if  typeof Foo  GetFields BindingFlags NonPublic   BindingFlags Instance  Any c   gt  c GetCustomAttributes typeof SomeAttribute   false  Any               do stuff

User · Answer

typeof MyType  GetField  fieldName   BindingFlags NonPublic   BindingFlags Instance

User · Answer

typeof MyType  GetField  fieldName   BindingFlags NonPublic   BindingFlags Instance

User · Answer

Use BindingFlags NonPublic and BindingFlags Instance flags  FieldInfo   fields   myType GetFields                           BindingFlags NonPublic                             BindingFlags Instance

User · Answer

One thing that you need to be aware of when reflecting on private members is that if your application is running in medium trust  as  for instance  when you are running on a shared hosting environment   it won t find them -- the BindingFlags NonPublic option will simply be ignored

User · Answer

Here is some extension methods for simple get and set private fields and properties  properties with setter    usage example        public class Foo               private int Bar   5             var targetObject   new Foo        var barValue   targetObject GetMemberValue  Bar     Result is 5     targetObject SetMemberValue  Bar   10    Sets Bar to 10    Code            lt summary gt          Extensions methos for using reflection to get   set member values          lt  summary gt      public static class ReflectionExtensions                    lt summary gt              Gets the public or private member using reflection               lt  summary gt               lt param name  obj  gt The source target  lt  param gt               lt param name  memberName  gt Name of the field or property  lt  param gt               lt returns gt the value of member lt  returns gt          public static object GetMemberValue this object obj  string memberName                        var memInf   GetMemberInfo obj  memberName                if  memInf    null                  throw new System Exception  memberName                 if  memInf is System Reflection PropertyInfo                  return memInf As lt System Reflection PropertyInfo gt    GetValue obj  null                if  memInf is System Reflection FieldInfo                  return memInf As lt System Reflection FieldInfo gt    GetValue obj                throw new System Exception                            lt summary gt              Gets the public or private member using reflection               lt  summary gt               lt param name  obj  gt The target object  lt  param gt               lt param name  memberName  gt Name of the field or property  lt  param gt               lt returns gt Old Value lt  returns gt          public static object SetMemberValue this object obj  string memberName  object newValue                        var memInf   GetMemberInfo obj  memberName                 if  memInf    null                  throw new System Exception  memberName                 var oldValue   obj GetMemberValue memberName                if  memInf is System Reflection PropertyInfo                  memInf As lt System Reflection PropertyInfo gt    SetValue obj  newValue  null               else if  memInf is System Reflection FieldInfo                  memInf As lt System Reflection FieldInfo gt    SetValue obj  newValue               else                 throw new System Exception                 return oldValue                          lt summary gt              Gets the member info              lt  summary gt               lt param name  obj  gt source object lt  param gt               lt param name  memberName  gt name of member lt  param gt               lt returns gt instanse of MemberInfo corresponsing to member lt  returns gt          private static System Reflection MemberInfo GetMemberInfo object obj  string memberName                        var prps   new System Collections Generic List lt System Reflection PropertyInfo gt                  prps Add obj GetType   GetProperty memberName                                                 System Reflection BindingFlags NonPublic   System Reflection BindingFlags Public   System Reflection BindingFlags Instance                                                  System Reflection BindingFlags FlattenHierarchy                prps   System Linq Enumerable ToList System Linq Enumerable Where  prps i   gt   ReferenceEquals i  null                 if  prps Count    0                  return prps 0                var flds   new System Collections Generic List lt System Reflection FieldInfo gt                  flds Add obj GetType   GetField memberName                                              System Reflection BindingFlags NonPublic   System Reflection BindingFlags Instance                                               System Reflection BindingFlags FlattenHierarchy                   to add more types of properties              flds   System Linq Enumerable ToList System Linq Enumerable Where flds  i   gt   ReferenceEquals i  null                  if  flds Count    0                  return flds 0                return null                      System Diagnostics DebuggerHidden          private static T As lt T gt  this object obj                        return  T obj

User · Answer

I came across this while searching for this on google so I realise I m bumping an old post  However the GetCustomAttributes requires two params   typeof Foo  GetFields BindingFlags NonPublic   BindingFlags Instance   Where x   gt  x GetCustomAttributes typeof SomeAttribute   false  Length  gt  0     The second parameter specifies whether or not you wish to search the inheritance hierarchy

User · Answer

You can do it just like with a property   FieldInfo fi   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance   if  fi GetCustomAttributes typeof SomeAttribute      null

User · Answer

Get private variable s value using Reflection   var  barVariable   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance  GetValue objectForFooClass     Set value for private variable using Reflection   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance  SetValue objectForFoocClass   newValue      Where objectForFooClass is a non null instance for the class type Foo

User · Answer

typeof MyType  GetField  fieldName   BindingFlags NonPublic   BindingFlags Instance

User · Answer

I came across this while searching for this on google so I realise I m bumping an old post  However the GetCustomAttributes requires two params   typeof Foo  GetFields BindingFlags NonPublic   BindingFlags Instance   Where x   gt  x GetCustomAttributes typeof SomeAttribute   false  Length  gt  0     The second parameter specifies whether or not you wish to search the inheritance hierarchy

User · Answer

One thing that you need to be aware of when reflecting on private members is that if your application is running in medium trust  as  for instance  when you are running on a shared hosting environment   it won t find them -- the BindingFlags NonPublic option will simply be ignored

User · Answer

Get private variable s value using Reflection   var  barVariable   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance  GetValue objectForFooClass     Set value for private variable using Reflection   typeof Foo  GetField   bar   BindingFlags NonPublic   BindingFlags Instance  SetValue objectForFoocClass   newValue      Where objectForFooClass is a non null instance for the class type Foo

User · Answer

Nice Syntax With Extension Method You can access any private field of an arbitrary type with code like this  Foo foo   new Foo    string c   foo GetFieldValue lt string gt   quot  bar quot     For that you need to define an extension method that will do the work for you  public static class ReflectionExtensions       public static T GetFieldValue lt T gt  this object obj  string name               Set the flags so that private and public fields from instances will be found         var bindingFlags   BindingFlags Public   BindingFlags NonPublic   BindingFlags Instance          var field   obj GetType   GetField name  bindingFlags           return  T field  GetValue obj

[c#] Find a private field with Reflection?

Examples related to c#

Examples related to .net

Examples related to reflection

Examples related to .net-attributes