Exception.ToString Exception.ToString Exception.ToString Exception.ToString Method

定义

创建并返回当前异常的字符串表示形式。Creates and returns a string representation of the current exception.

public:
 override System::String ^ ToString();
public override string ToString ();
override this.ToString : unit -> string
Public Overrides Function ToString () As String

返回

当前异常的字符串表示形式。A string representation of the current exception.

实现

示例

下面的示例将引发异常, 并显示对此异常ToString调用的结果。The following example causes an exception and displays the result of calling ToString on that exception. 请注意, Exception.ToString当异常类实例出现在Console.WriteLine方法的参数列表中时, 将隐式调用方法。Note that the Exception.ToString method is called implicitly when the Exception class instance appears in the argument list of the Console.WriteLine method.

using namespace System;

public ref class TestClass{};

int main()
{
   TestClass^ test = gcnew TestClass;
   array<Object^>^ objectsToCompare = { test, test->ToString(), 123,
                                        (123).ToString(), "some text",
                                        "Some Text" };
   String^ s = "some text";
   for each (Object^ objectToCompare in objectsToCompare) {
      try {
         Int32 i = s->CompareTo(objectToCompare);
         Console::WriteLine("Comparing '{0}' with '{1}': {2}",
                            s, objectToCompare, i);
      }
      catch (ArgumentException^ e) {
            Console::WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare->GetType()->Name);
            Console::WriteLine("Exception information: {0}", e);
      }
      Console::WriteLine();
   }
}
// The example displays the following output:
//     Bad argument: TestClass (type TestClass)
//     Exception information: System.ArgumentException: Object must be of type String.
//        at System.String.CompareTo(Object value)
//        at Example.Main()
//     
//     Comparing 'some text' with 'TestClass': -1
//     
//     Bad argument: 123 (type Int32)
//     Exception information: System.ArgumentException: Object must be of type String.
//        at System.String.CompareTo(Object value)
//        at Example.Main()
//     
//     Comparing 'some text' with '123': 1
//     
//     Comparing 'some text' with 'some text': 0
//     
//     Comparing 'some text' with 'Some Text': -1
using System;

public class TestClass
{}

public class Example 
{
   public static void Main()
   {
      var test = new TestClass();
      Object[] objectsToCompare = { test, test.ToString(), 123,
                                    123.ToString(), "some text",
                                    "Some Text" };
      string s = "some text";
      foreach (var objectToCompare in objectsToCompare) {
         try {
            int i = s.CompareTo(objectToCompare);
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i);
         }
         catch (ArgumentException e) {
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name);
            Console.WriteLine("Exception information: {0}", e);
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//     Bad argument: TestClass (type TestClass)
//     Exception information: System.ArgumentException: Object must be of type String.
//        at System.String.CompareTo(Object value)
//        at Example.Main()
//     
//     Comparing 'some text' with 'TestClass': -1
//     
//     Bad argument: 123 (type Int32)
//     Exception information: System.ArgumentException: Object must be of type String.
//        at System.String.CompareTo(Object value)
//        at Example.Main()
//     
//     Comparing 'some text' with '123': 1
//     
//     Comparing 'some text' with 'some text': 0
//     
//     Comparing 'some text' with 'Some Text': -1
Public Class TestClass
End Class 

Public Class Example
   Public Shared Sub Main()
      Dim test As New TestClass()
      Dim objectsToCompare() As Object = { test, test.ToString(), 123,
                                           123.ToString(), "some text",
                                           "Some Text" }
      Dim s As String = "some text"
      For Each objectToCompare In objectsToCompare
         Try
            Dim i As Integer = s.CompareTo(objectToCompare)
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i)
         Catch e As ArgumentException
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name)
            Console.WriteLine("Exception information: {0}", e)
         End Try
         Console.WriteLine()
      Next
   End Sub 
End Class 
' The example displays the following output:
'     Bad argument: TestClass (type TestClass)
'     Exception information: System.ArgumentException: Object must be of type String.
'        at System.String.CompareTo(Object value)
'        at Example.Main()
'     
'     Comparing 'some text' with 'TestClass': -1
'     
'     Bad argument: 123 (type Int32)
'     Exception information: System.ArgumentException: Object must be of type String.
'        at System.String.CompareTo(Object value)
'        at Example.Main()
'     
'     Comparing 'some text' with '123': 1
'     
'     Comparing 'some text' with 'some text': 0
'     
'     Comparing 'some text' with 'Some Text': -1

注解

ToString返回当前异常的表示形式, 该异常旨在被人理解。ToString returns a representation of the current exception that is intended to be understood by humans. 如果异常包含区分区域性的数据, ToString则需要使用返回的字符串表示形式来考虑当前系统区域性。Where the exception contains culture-sensitive data, the string representation returned by ToString is required to take into account the current system culture. 虽然对于返回的字符串的格式没有确切的要求, 但它应尝试反映用户认为对象的值。Although there are no exact requirements for the format of the returned string, it should attempt to reflect the value of the object as perceived by the user.

ToString默认实现将获取引发当前异常的类的名称、消息、对内部异常调用ToString的结果和调用Environment.StackTrace的结果。The default implementation of ToString obtains the name of the class that threw the current exception, the message, the result of calling ToString on the inner exception, and the result of calling Environment.StackTrace. 如果这些成员中有任何null一个为, 则其值不包含在返回的字符串中。If any of these members is null, its value is not included in the returned string.

如果没有错误消息或为空字符串 (""), 则不返回错误消息。If there is no error message or if it is an empty string (""), then no error message is returned. 内部异常的名称和堆栈跟踪仅在不null返回时返回。The name of the inner exception and the stack trace are returned only if they are not null.

此方法重写 Object.ToStringThis method overrides Object.ToString.

适用于