C# | Type.GetField() Method

Last Updated : 10 Dec, 2019

Type.GetField() Method is used to get a specific field of the current Type. There are 2 methods in the overload list of this method as follows:

GetField(String) Method
GetField(String, BindingFlags) Method

GetField(String) Method

This method is used to search for the public field with the specified name.

Syntax: public System.Reflection.FieldInfo GetField (string name);
Here, it takes the string containing the name of the data field to get.

Return Value: This method returns an object representing the public field with the specified name if found otherwise, null.

Exception: This method throws ArgumentNullException if the name is null .

Below programs illustrate the use of Type.GetField() Method:

Example 1:

   // C# program to demonstrate the 
// Type.GetField(String) Method 
using System; 
using System.Globalization; 
using System.Reflection; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        // Declaring and initializing object of Type 
        Type objType = typeof(Student); 
  
        // try-catch block for handling Exception 
        try { 
  
            // Getting FieldInfo by 
            // using GetField(String) Method 
            FieldInfo info = objType.GetField("Name"); 
  
            // Display the Result 
            Console.WriteLine("FieldInfo is: {0}", info); 
        } 
  
        // catch ArgumentNullException here 
        catch (ArgumentNullException e)  
        { 
            Console.Write("name is null."); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
} 
  
// Defining class Student 
public class Student  
{ 
    public string Name = "Rahul"; 
    public string Dept = "Electrical"; 
    public int Roll = 10; 
} 
 
  

Output:

  FieldInfo is: System.String Name

Example 2: For ArgumentNullException

   // C# program to demonstrate the 
// Type.GetField(String) Method 
using System; 
using System.Globalization; 
using System.Reflection; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        // Declaring and initializing object of Type 
        Type objType = typeof(Student); 
  
        // try-catch block for handling Exception 
        try { 
  
            // Getting FieldInfo by 
            // using GetField() Method 
            FieldInfo info = objType.GetField(null); 
  
            // Display the Result 
            Console.WriteLine("FieldInfo is: {0}", info); 
        } 
  
        // catch ArgumentNullException here 
        catch (ArgumentNullException e) 
        { 
            Console.WriteLine("Name is null."); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
} 
  
// Defining class Student 
public class Student  
{ 
    public string Name = "Rahul"; 
    public string Dept = "Electrical"; 
    public int Roll = 10; 
} 
 
  

Output:

  name is null.  Exception Thrown: System.ArgumentNullException

GetField(String, BindingFlags) Method

This method is used to search for the specified field, using the specified binding constraints.

Syntax: public abstract System.Reflection.FieldInfo GetField (string name, System.Reflection.BindingFlags bindingAttr);

Parameters:

name: The string containing the name of the data field to get.
bindingAttr: It is a bitmask comprised of one or more BindingFlags that specify how the search is conducted or Zero, to return null.

Return Value: This method returns an object representing the field that matches the specified requirements if found otherwise, null.

Exception: This method throws ArgumentNullException if name is null.

Below programs illustrate the use of the above-discussed method:

Example 1:

   // C# program to demonstrate the 
// Type.GetField(String) Method 
using System; 
using System.Globalization; 
using System.Reflection; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        // Declaring and initializing object of Type 
        Type objType = typeof(Student); 
  
        // try-catch block for handling Exception 
        try { 
  
            // You must specify either BindingFlags.Instance 
            // or BindingFlags.Static 
            // and Specify BindingFlags.Public 
            // to include public fields in the search 
            BindingFlags battr = BindingFlags.Public | BindingFlags.Instance; 
  
            // Getting FieldInfo by 
            // using GetField() Method 
            FieldInfo info = objType.GetField("Name", battr); 
  
            // Display the Result 
            Console.WriteLine("FieldInfo is: {0}", info); 
        } 
  
        // catch ArgumentNullException here 
        catch (ArgumentNullException e)  
       { 
            Console.Write("name is null."); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
} 
  
// Defining class Student 
public class Student  
{ 
    public string Name = "Rahul"; 
    public string Dept = "Electrical"; 
    public int Roll = 10; 
} 
 
  

Output:

  FieldInfo is: System.String Name

Example 2: For ArgumentNullException

   // C# program to demonstrate the 
// Type.GetField(String) Method 
using System; 
using System.Globalization; 
using System.Reflection; 
  
class GFG { 
  
    // Main Method 
    public static void Main() 
    { 
        // Declaring and initializing object of Type 
        Type objType = typeof(Student); 
  
        // try-catch block for handling Exception 
        try { 
  
            // You must specify either BindingFlags.Instance  
            // or BindingFlags.Static 
            // and Specify BindingFlags.Public 
            // to include public fields in the search 
            BindingFlags battr = BindingFlags.Public | BindingFlags.Instance; 
  
            // Getting FieldInfo by 
            // using GetField() Method 
            FieldInfo info = objType.GetField(null, battr); 
  
            // Display the Result 
            Console.WriteLine("FieldInfo is: {0}", info); 
        } 
  
        // catch ArgumentNullException here 
        catch (ArgumentNullException e)  
        { 
            Console.WriteLine("name is null."); 
            Console.Write("Exception Thrown: "); 
            Console.Write("{0}", e.GetType(), e.Message); 
        } 
    } 
} 
  
// Defining class Student 
public class Student  
{ 
    public string Name = "Rahul"; 
    public string Dept = "Electrical"; 
    public int Roll = 10; 
} 
 
  

Output:

  name is null.  Exception Thrown: System.ArgumentNullException

Reference:

https://docs.microsoft.com/en-us/dotnet/api/system.type.getfield?view=netframework-4.8

C# | Type.GetFields() Method

RohitPrasad3

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Article Tags :

C# | Type.GetField() Method

GetField(String) Method

GetField(String, BindingFlags) Method

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