1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
<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 : 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>
<AssemblyVersion>2.0.0.0</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>
<Base>
<BaseTypeName>System.SystemException</BaseTypeName>
</Base>
<Interfaces />
<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 CIL 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>
<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>
<AssemblyInfo>
<AssemblyVersion>1.0.5000.0</AssemblyVersion>
<AssemblyVersion>2.0.0.0</AssemblyVersion>
</AssemblyInfo>
</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>
<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>
<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 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>
<AssemblyInfo>
<AssemblyVersion>1.0.5000.0</AssemblyVersion>
<AssemblyVersion>2.0.0.0</AssemblyVersion>
</AssemblyInfo>
</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>
<param name="info">To be added.</param>
<param name="context">To be added.</param>
<summary>To be added.</summary>
<remarks>To be added.</remarks>
</Docs>
<AssemblyInfo>
<AssemblyVersion>1.0.5000.0</AssemblyVersion>
<AssemblyVersion>2.0.0.0</AssemblyVersion>
</AssemblyInfo>
</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>
<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>
<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 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>
<AssemblyInfo>
<AssemblyVersion>1.0.5000.0</AssemblyVersion>
<AssemblyVersion>2.0.0.0</AssemblyVersion>
</AssemblyInfo>
</Member>
</Members>
<TypeExcluded>0</TypeExcluded>
<Attributes>
<Attribute>
<AttributeName>System.Runtime.InteropServices.ComVisible(true)</AttributeName>
</Attribute>
</Attributes>
</Type>
|
