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<Type Name="NullReferenceException" FullName="System.NullReferenceException" FullNameSP="System_NullReferenceException" Maintainer="ecma">
<TypeSignature Language="ILASM" Value=".class public serializable NullReferenceException extends System.SystemException" />
<TypeSignature Language="C#" Value="public class NullReferenceException : System.SystemException" />
<MemberOfLibrary>BCL</MemberOfLibrary>
<AssemblyInfo>
<AssemblyName>mscorlib</AssemblyName>
<AssemblyPublicKey>[00 00 00 00 00 00 00 00 04 00 00 00 00 00 00 00 ]</AssemblyPublicKey>
<AssemblyVersion>1.0.5000.0</AssemblyVersion>
</AssemblyInfo>
<ThreadingSafetyStatement>All public static members of this type are safe for multithreaded operations. No instance members are guaranteed to be thread safe.</ThreadingSafetyStatement>
<Docs>
<summary>
<para> Represents the error that occurs when there is an attempt
to dereference a null object reference.</para>
</summary>
<remarks>
<block subset="none" type="note">
<para>Applications throw the <see cref="T:System.ArgumentNullException" />
rather than <see cref="T:System.NullReferenceException" />
.</para>
<para>The following IL instructions throw <see cref="T:System.NullReferenceException" />
:</para>
<list type="bullet">
<item>
<term>
callvirt</term>
</item>
<item>
<term>cpblk</term>
</item>
<item>
<term>cpobj</term>
</item>
<item>
<term>ldelema</term>
</item>
<item>
<term>ldelem.<type></term>
</item>
<item>
<term>ldfld</term>
</item>
<item>
<term>ldflda</term>
</item>
<item>
<term>ldind.<type></term>
</item>
<item>
<term>ldlen</term>
</item>
<item>
<term>stelem.<type></term>
</item>
<item>
<term>stind.<type></term>
</item>
<item>
<term>stfld</term>
</item>
<item>
<term>throw</term>
</item>
<item>
<term>unbox</term>
</item>
<item>
<term>initblk</term>
</item>
</list>
</block>
</remarks>
<example>
<para>The following example demonstrates an error that causes
a <see cref="T:System.NullReferenceException" /> exception.</para>
<code lang="C#">using System;
public class Ints {
public int[] myInts;
}
public class NullRefExample {
public static void Main() {
Ints ints = new Ints();
try {
int i = ints.myInts[0];
}
catch( NullReferenceException e ) {
Console.WriteLine( "Caught error: {0}.", e);
}
}
}
</code>
<para>The output is</para>
<code>
Caught error: System.NullReferenceException: Object reference not set to an instance of an object.
at NullRefExample.Main().
</code>
</example>
</Docs>
<Base>
<BaseTypeName>System.SystemException</BaseTypeName>
</Base>
<Interfaces />
<Members>
<Member MemberName=".ctor">
<MemberSignature Language="ILASM" Value="public rtspecialname specialname instance void .ctor()" />
<MemberSignature Language="C#" Value="public NullReferenceException ();" />
<MemberType>Constructor</MemberType>
<ReturnValue />
<Parameters />
<Docs>
<summary>
<para>Constructs and initializes a new instance of the <see cref="T:System.NullReferenceException" />
class.</para>
</summary>
<remarks>
<para>This constructor initializes the <see cref="!:System.NullReferenceException.Message" /> property of the new instance to a system-supplied
message that describes the error, such as "The value 'null' was found where an
instance of an object was required." This message takes into account the current
system culture.</para>
<para>The <see cref="!:System.NullReferenceException.InnerException" /> property is initialized to
<see langword="null" />.</para>
</remarks>
</Docs>
<Excluded>0</Excluded>
</Member>
<Member MemberName=".ctor">
<MemberSignature Language="ILASM" Value="public rtspecialname specialname instance void .ctor(string message)" />
<MemberSignature Language="C#" Value="public NullReferenceException (string message);" />
<MemberType>Constructor</MemberType>
<ReturnValue />
<Parameters>
<Parameter Name="message" Type="System.String" />
</Parameters>
<Docs>
<summary>
<para>Constructs and initializes a new instance of the <see cref="T:System.NullReferenceException" />
class.</para>
</summary>
<param name="message">A <see cref="T:System.String" /> that describes the error. The content of <paramref name="message" /> is intended to be understood by humans. The caller of this constructor is required to ensure that this string has been localized for the current system culture.</param>
<remarks>
<para>This constructor initializes the <see cref="!:System.NullReferenceException.Message" /> property of the new instance using <paramref name="message" />. If <paramref name="message" /> is
<see langword="null" />, the <see cref="!:System.NullReferenceException.Message" /> property is initialized to the
system-supplied message provided by the constructor that takes no arguments. The <see cref="!:System.NullReferenceException.InnerException" /> property is initialized to <see langword="null" />.</para>
</remarks>
</Docs>
<Excluded>0</Excluded>
</Member>
<Member MemberName=".ctor">
<MemberSignature Language="ILASM" Value="public rtspecialname specialname instance void .ctor(string message, class System.Exception innerException)" />
<MemberSignature Language="C#" Value="public NullReferenceException (string message, Exception innerException);" />
<MemberType>Constructor</MemberType>
<ReturnValue />
<Parameters>
<Parameter Name="message" Type="System.String" />
<Parameter Name="innerException" Type="System.Exception" />
</Parameters>
<Docs>
<summary>
<para>Constructs and initializes a new instance of the <see cref="T:System.NullReferenceException" />
class.</para>
</summary>
<param name="message">A <see cref="T:System.String" /> that describes the error. The content of <paramref name="message" /> is intended to be understood by humans. The caller of this constructor is required to ensure that this string has been localized for the current system culture.</param>
<param name="innerException">An instance of <see cref="T:System.Exception" /> that is the cause of the current Exception. If <paramref name="innerException" /> is non-null, then the current Exception was raised in a catch block handling <paramref name="innerException" /> .</param>
<remarks>
<para>This constructor initializes the <see cref="!:System.NullReferenceException.Message" /> property of the new instance using <paramref name="message" />, and
the <see cref="!:System.NullReferenceException.InnerException" /> property using
<paramref name="innerException" />. If <paramref name="message" /> is
<see langword="null" />, the <see cref="!:System.NullReferenceException.Message" /> property is initialized to the
system-supplied message provided by the constructor that takes no arguments.</para>
<para>
<block subset="none" type="note">For information on
inner exceptions, see <see cref="P:System.Exception.InnerException" />
.</block>
</para>
</remarks>
</Docs>
<Excluded>0</Excluded>
</Member>
<Member MemberName=".ctor">
<MemberSignature Language="C#" Value="protected NullReferenceException (System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context);" />
<MemberType>Constructor</MemberType>
<Parameters>
<Parameter Name="info" Type="System.Runtime.Serialization.SerializationInfo" />
<Parameter Name="context" Type="System.Runtime.Serialization.StreamingContext" />
</Parameters>
<Docs>
<summary>To be added.</summary>
<param name="info">To be added.</param>
<param name="context">To be added.</param>
<remarks>To be added.</remarks>
</Docs>
</Member>
</Members>
<TypeExcluded>0</TypeExcluded>
</Type>
|
