DebuggerDisplayAttribute Class

Definition

public ref class DebuggerDisplayAttribute sealed : Attribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Enum | System.AttributeTargets.Field | System.AttributeTargets.Property | System.AttributeTargets.Struct, AllowMultiple=true)]
public sealed class DebuggerDisplayAttribute : Attribute

[System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Enum | System.AttributeTargets.Field | System.AttributeTargets.Property | System.AttributeTargets.Struct, AllowMultiple=true)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class DebuggerDisplayAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Enum | System.AttributeTargets.Field | System.AttributeTargets.Property | System.AttributeTargets.Struct, AllowMultiple=true)>]
type DebuggerDisplayAttribute = class
 inherit Attribute

[<System.AttributeUsage(System.AttributeTargets.Assembly | System.AttributeTargets.Class | System.AttributeTargets.Delegate | System.AttributeTargets.Enum | System.AttributeTargets.Field | System.AttributeTargets.Property | System.AttributeTargets.Struct, AllowMultiple=true)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type DebuggerDisplayAttribute = class
 inherit Attribute

Public NotInheritable Class DebuggerDisplayAttribute
Inherits Attribute

Inheritance

Object

Attribute

DebuggerDisplayAttribute

Attributes

AttributeUsageAttribute ComVisibleAttribute

Examples

View the following example in Visual Studio to see the results of applying the DebuggerDisplayAttribute.

using System;
using System.Collections;
using System.Diagnostics;
using System.Reflection;

class DebugViewTest
{
 // The following constant will appear in the debug window for DebugViewTest.
 const string TabString = " ";
 // The following DebuggerBrowsableAttribute prevents the property following it
 // from appearing in the debug window for the class.
 [DebuggerBrowsable(DebuggerBrowsableState.Never)]
 public static string y = "Test String";

 static void Main()
 {
 MyHashtable myHashTable = new MyHashtable();
 myHashTable.Add("one", 1);
 myHashTable.Add("two", 2);
 Console.WriteLine(myHashTable.ToString());
 Console.WriteLine("In Main.");
 }
}
[DebuggerDisplay("{value}", Name = "{key}")]
internal class KeyValuePairs
{
 private IDictionary dictionary;
 private object key;
 private object value;

 public KeyValuePairs(IDictionary dictionary, object key, object value)
 {
 this.value = value;
 this.key = key;
 this.dictionary = dictionary;
 }
}
[DebuggerDisplay("Count = {Count}")]
[DebuggerTypeProxy(typeof(HashtableDebugView))]
class MyHashtable : Hashtable
{
 private const string TestString = "This should not appear in the debug window.";

 internal class HashtableDebugView
 {
 private Hashtable hashtable;
 public const string TestString = "This should appear in the debug window.";
 public HashtableDebugView(Hashtable hashtable)
 {
 this.hashtable = hashtable;
 }

 [DebuggerBrowsable(DebuggerBrowsableState.RootHidden)]
 public KeyValuePairs[] Keys
 {
 get
 {
 KeyValuePairs[] keys = new KeyValuePairs[hashtable.Count];

 int i = 0;
 foreach(object key in hashtable.Keys)
 {
 keys[i] = new KeyValuePairs(hashtable, key, hashtable[key]);
 i++;
 }
 return keys;
 }
 }
 }
}

Imports System.Collections
Imports System.Diagnostics
Imports System.Reflection



Class DebugViewTest
 ' The following constant will appear in the debug window for DebugViewTest.
 Const TabString As String = " "
 ' The following DebuggerBrowsableAttribute prevents the property following it
 ' from appearing in the debug window for the class.
 <DebuggerBrowsable(DebuggerBrowsableState.Never)> _
 Public Shared y As String = "Test String"

 Shared Sub Main() 
 Dim myHashTable As New MyHashtable()
 myHashTable.Add("one", 1)
 myHashTable.Add("two", 2)
 Console.WriteLine(myHashTable.ToString())
 Console.WriteLine("In Main.")

 End Sub
End Class
<DebuggerDisplay("{value}", Name := "{key}")> _
Friend Class KeyValuePairs
 Private dictionary As IDictionary
 Private key As Object
 Private value As Object
 
 
 Public Sub New(ByVal dictionary As IDictionary, ByVal key As Object, ByVal value As Object) 
 Me.value = value
 Me.key = key
 Me.dictionary = dictionary

 End Sub
End Class
<DebuggerDisplay("Count = {Count}"), DebuggerTypeProxy(GetType(MyHashtable.HashtableDebugView))> _
Class MyHashtable
 Inherits Hashtable
 Private Const TestString As String = "This should not appear in the debug window."

 Friend Class HashtableDebugView
 Private hashtable As Hashtable
 Public Shared TestString As String = "This should appear in the debug window."

 Public Sub New(ByVal hashtable As Hashtable)
 Me.hashtable = hashtable
 End Sub

 <DebuggerBrowsable(DebuggerBrowsableState.RootHidden)> _
 ReadOnly Property Keys as KeyValuePairs()
 Get
 Dim nkeys(hashtable.Count) as KeyValuePairs

 Dim i as Integer = 0
 For Each key As Object In hashtable.Keys
 nkeys(i) = New KeyValuePairs(hashtable, key, hashtable(key))
 i = i + 1
 Next
 Return nkeys
 End Get
 End Property

 End Class
End Class

Remarks

The DebuggerDisplayAttribute constructor has a single argument: a string to be displayed in the value column for instances of the type. This string can contain braces ({ and }). The text within a pair of braces is evaluated as the name of a field, property, or method. For example, the following C# code causes "Count = 4" to be displayed when the plus sign (+) is selected to expand the debugger display for an instance of MyHashtable.

[DebuggerDisplay("Count = {count}")]
class MyHashtable
{
 public int count = 4;
}

For information about using this attribute in Visual Studio, see Using the DebuggerDisplay Attribute.