Exception.Message 属性
获取描述当前异常的消息。
**命名空间:**System
**程序集:**mscorlib（在 mscorlib.dll 中）
语法
声明
Public Overridable ReadOnly Property Message As String
用法
Dim instance As Exception
Dim value As String
value = instance.Message
public virtual string Message { get; }
public:
virtual property String^ Message {
String^ get ();
}
/** @property */
public String get_Message ()
public function get Message () : String
属性值
解释异常原因的错误信息或空字符串 ("")。
备注
Message 的文本应当完全描述错误，并且如果可能，应阐释如何纠正错误。Message 属性的值包含在 ToString 所返回的信息中。
仅当创建 Exception 时才设置 Message 属性。如果对于当前实例没有向构造函数提供消息，则系统将提供使用当前系统区域性格式化的默认消息。
给继承者的说明 在需要控制消息内容或格式的类中重写 Message 属性。应用程序代码在需要显示捕捉到的异常的信息时通常会访问此属性。 应本地化错误信息。
示例
下面的代码示例引发然后捕捉一个 Exception，并使用 Message 属性显示该异常的文本消息。
' Example for the Exception.HelpLink, Exception.Source,
' Exception.StackTrace, and Exception.TargetSite properties.
Imports System
Imports Microsoft.VisualBasic
Namespace NDP_UE_VB
' Derive an exception; the constructor sets the HelpLink and
' Source properties.
Class LogTableOverflowException
Inherits Exception
Private Const overflowMessage As String = _
"The log table has overflowed."
Public Sub New( auxMessage As String, inner As Exception )
MyBase.New( String.Format( "{0} - {1}", _
overflowMessage, auxMessage ), inner )
Me.HelpLink = "https://msdn.microsoft.com"
Me.Source = "Exception_Class_Samples"
End Sub ' New
End Class ' LogTableOverflowException
Class LogTable
Public Sub New(numElements As Integer)
logArea = New String(numElements) {}
elemInUse = 0
End Sub ' New
Protected logArea() As String
Protected elemInUse As Integer
' The AddRecord method throws a derived exception if
' the array bounds exception is caught.
Public Function AddRecord( newRecord As String ) As Integer
Try
Dim curElement as Integer = elemInUse
logArea( elemInUse ) = newRecord
elemInUse += 1
Return curElement
Catch ex As Exception
Throw New LogTableOverflowException( _
String.Format( "Record ""{0}"" was not logged.", _
newRecord ), ex )
End Try
End Function ' AddRecord
End Class ' LogTable
Module OverflowDemo
' Create a log table and force an overflow.
Sub Main( )
Dim log As New LogTable( 4 )
Console.WriteLine( "This example of " & vbCrLf & _
" Exception.Message, " & vbCrLf & _
" Exception.HelpLink, " & vbCrLf & _
" Exception.Source, " & vbCrLf & _
" Exception.StackTrace, and " & vbCrLf & _
" Exception.TargetSite " & vbCrLf & _
"generates the following output." )
Try
Dim count As Integer = 0
Do
log.AddRecord( _
String.Format( "Log record number {0}", count ) )
count += 1
Loop
Catch ex As Exception
Console.WriteLine( vbCrLf & _
"Message ---" & vbCrLf & ex.Message )
Console.WriteLine( vbCrLf & _
"HelpLink ---" & vbCrLf & ex.HelpLink )
Console.WriteLine( vbCrLf & _
"Source ---" & vbCrLf & ex.Source )
Console.WriteLine( vbCrLf & _
"StackTrace ---" & vbCrLf & ex.StackTrace )
Console.WriteLine( vbCrLf & "TargetSite ---" & _
vbCrLf & ex.TargetSite.ToString( ) )
End Try
End Sub ' Main
End Module ' OverflowDemo
End Namespace ' NDP_UE_VB
' This example of
' Exception.Message,
' Exception.HelpLink,
' Exception.Source,
' Exception.StackTrace, and
' Exception.TargetSite
' generates the following output.
'
' Message ---
' The log table has overflowed. - Record "Log record number 5" was not logged.
'
' HelpLink ---
' https://msdn.microsoft.com
'
' Source ---
' Exception_Class_Samples
'
' StackTrace ---
' at NDP_UE_VB.LogTable.AddRecord(String newRecord)
' at NDP_UE_VB.OverflowDemo.Main()
'
' TargetSite ---
' Int32 AddRecord(System.String)
// Example for the Exception.HelpLink, Exception.Source,
// Exception.StackTrace, and Exception.TargetSite properties.
using System;
namespace NDP_UE_CS
{
// Derive an exception; the constructor sets the HelpLink and
// Source properties.
class LogTableOverflowException : Exception
{
const string overflowMessage = "The log table has overflowed.";
public LogTableOverflowException(
string auxMessage, Exception inner ) :
base( String.Format( "{0} - {1}",
overflowMessage, auxMessage ), inner )
{
this.HelpLink = "https://msdn.microsoft.com";
this.Source = "Exception_Class_Samples";
}
}
class LogTable
{
public LogTable( int numElements )
{
logArea = new string[ numElements ];
elemInUse = 0;
}
protected string[ ] logArea;
protected int elemInUse;
// The AddRecord method throws a derived exception if
// the array bounds exception is caught.
public int AddRecord( string newRecord )
{
try
{
logArea[ elemInUse ] = newRecord;
return elemInUse++;
}
catch( Exception e )
{
throw new LogTableOverflowException(
String.Format( "Record \"{0}\" was not logged.",
newRecord ), e );
}
}
}
class OverflowDemo
{
// Create a log table and force an overflow.
public static void Main()
{
LogTable log = new LogTable( 4 );
Console.WriteLine(
"This example of \n Exception.Message, \n" +
" Exception.HelpLink, \n Exception.Source, \n" +
" Exception.StackTrace, and \n Exception." +
"TargetSite \ngenerates the following output." );
try
{
for( int count = 1; ; count++ )
{
log.AddRecord(
String.Format(
"Log record number {0}", count ) );
}
}
catch( Exception ex )
{
Console.WriteLine( "\nMessage ---\n{0}", ex.Message );
Console.WriteLine(
"\nHelpLink ---\n{0}", ex.HelpLink );
Console.WriteLine( "\nSource ---\n{0}", ex.Source );
Console.WriteLine(
"\nStackTrace ---\n{0}", ex.StackTrace );
Console.WriteLine(
"\nTargetSite ---\n{0}", ex.TargetSite );
}
}
}
}
/*
This example of
Exception.Message,
Exception.HelpLink,
Exception.Source,
Exception.StackTrace, and
Exception.TargetSite
generates the following output.
Message ---
The log table has overflowed. - Record "Log record number 5" was not logged.
HelpLink ---
https://msdn.microsoft.com
Source ---
Exception_Class_Samples
StackTrace ---
at NDP_UE_CS.LogTable.AddRecord(String newRecord)
at NDP_UE_CS.OverflowDemo.Main()
TargetSite ---
Int32 AddRecord(System.String)
*/
// Example for the Exception::HelpLink, Exception::Source,
// Exception::StackTrace, and Exception::TargetSite properties.
using namespace System;
namespace NDP_UE_CPP
{
// Derive an exception; the constructor sets the HelpLink and
// Source properties.
public ref class LogTableOverflowException: public Exception
{
private:
static String^ overflowMessage = "The log table has overflowed.";
public:
LogTableOverflowException( String^ auxMessage, Exception^ inner )
: Exception( String::Format( "{0} - {1}", overflowMessage, auxMessage ), inner )
{
this->HelpLink = "https://msdn.microsoft.com";
this->Source = "Exception_Class_Samples";
}
};
public ref class LogTable
{
public:
LogTable( int numElements )
{
logArea = gcnew array<String^>(numElements);
elemInUse = 0;
}
protected:
array<String^>^logArea;
int elemInUse;
public:
// The AddRecord method throws a derived exception if
// the array bounds exception is caught.
int AddRecord( String^ newRecord )
{
try
{
logArea[ elemInUse ] = newRecord;
return elemInUse++;
}
catch ( Exception^ ex )
{
throw gcnew LogTableOverflowException( String::Format( "Record \"{0}\" was not logged.", newRecord ),ex );
}
}
};
// Create a log table and force an overflow.
void ForceOverflow()
{
LogTable^ log = gcnew LogTable( 4 );
try
{
for ( int count = 1; ; count++ )
{
log->AddRecord( String::Format( "Log record number {0}", count ) );
}
}
catch ( Exception^ ex )
{
Console::WriteLine( "\nMessage ---\n{0}", ex->Message );
Console::WriteLine( "\nHelpLink ---\n{0}", ex->HelpLink );
Console::WriteLine( "\nSource ---\n{0}", ex->Source );
Console::WriteLine( "\nStackTrace ---\n{0}", ex->StackTrace );
Console::WriteLine( "\nTargetSite ---\n{0}", ex->TargetSite->ToString() );
}
}
}
int main()
{
Console::WriteLine( "This example of \n Exception::Message, \n"
" Exception::HelpLink, \n Exception::Source, \n"
" Exception::StackTrace, and \n Exception::"
"TargetSite \ngenerates the following output." );
NDP_UE_CPP::ForceOverflow();
}
/*
This example of
Exception::Message,
Exception::HelpLink,
Exception::Source,
Exception::StackTrace, and
Exception::TargetSite
generates the following output.
Message ---
The log table has overflowed. - Record "Log record number 5" was not logged.
HelpLink ---
https://msdn.microsoft.com
Source ---
Exception_Class_Samples
StackTrace ---
at NDP_UE_CPP.LogTable.AddRecord(String newRecord)
at NDP_UE_CPP.ForceOverflow()
TargetSite ---
Int32 AddRecord(System.String)
*/
// Example for the Exception.HelpLink, Exception.Source,
// Exception.StackTrace, and Exception.TargetSite properties.
package NDP_UE_JSL;
import System.* ;
// Derive an exception; the constructor sets the HelpLink and
// Source properties.
class LogTableOverflowException extends System.Exception
{
private String overflowMessage = "The log table has overflowed.";
public LogTableOverflowException(System.String auxMessage,
System.Exception inner)
{
super(String.Format("The log table has overflowed. - {0}",
auxMessage), inner);
this.set_HelpLink("https://msdn.microsoft.com");
this.set_Source("Exception_Class_Samples");
} //LogTableOverflowException
} //LogTableOverflowException
class LogTable
{
public LogTable(int numElements)
{
logArea = new String[numElements];
elemInUse = 0;
} //LogTable
protected String logArea[];
protected int elemInUse;
// The AddRecord method throws a derived exception if
// the array bounds exception is caught.
public int AddRecord(String newRecord) throws LogTableOverflowException
{
try {
logArea.set_Item(elemInUse, newRecord);
return elemInUse++;
}
catch (System.Exception e) {
throw new LogTableOverflowException(
String.Format("Record \"{0}\" was not logged.", newRecord), e);
}
} //AddRecord
} //LogTable
class OverflowDemo
{
// Create a log table and force an overflow.
public static void main(String[] args)
{
LogTable log = new LogTable(4);
Console.WriteLine(("This example of \n Exception.Message, \n"
+ " Exception.HelpLink, \n Exception.Source, \n"
+ " Exception.StackTrace, and \n Exception."
+ "TargetSite \ngenerates the following output."));
try {
for (int count = 1; ; count++) {
log.AddRecord(String.Format("Log record number {0}",
System.Convert.ToString(count)));
}
}
catch (System.Exception ex) {
Console.WriteLine("\nMessage ---\n{0}", ex.get_Message());
Console.WriteLine("\nHelpLink ---\n{0}", ex.get_HelpLink());
Console.WriteLine("\nSource ---\n{0}", ex.get_Source());
Console.WriteLine("\nStackTrace ---\n{0}", ex.get_StackTrace());
Console.WriteLine("\nTargetSite ---\n{0}", ex.get_TargetSite());
}
} //main
} //OverflowDemo
/*
Exception.Message,
Exception.HelpLink,
Exception.Source,
Exception.StackTrace, and
Exception.TargetSite
generates the following output.
Message ---
The log table has overflowed. - Record "Log record number 5" was not logged.
HelpLink ---
https://msdn.microsoft.com
Source ---
Exception_Class_Samples
StackTrace ---
at NDP_UE_JSL.LogTable.AddRecord(String newRecord) in D:\Test\ConsoleApplicat
ion7\ConsoleApplication7\Class1.jsl:line 45
at NDP_UE_JSL.OverflowDemo.main(String[] args) in D:\Test\ConsoleApplication7
\ConsoleApplication7\Class1.jsl:line 62
TargetSite ---
Int32 AddRecord(System.String)
*/
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
.NET Compact Framework
受以下版本支持：2.0、1.0