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

定義

建立並傳回目前例外狀況的字串表示。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

傳回

目前例外狀況的字串表示。A string representation of the current exception.

實作

範例

下列範例會導致例外狀況,並顯示呼叫ToString該例外狀況。The following example causes an exception and displays the result of calling ToString on that exception. 請注意,Exception.ToString的引數清單中出現的例外狀況類別執行個體時隱含地呼叫方法Console.WriteLine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

備註

ToString 傳回表示目前的例外狀況,目的是讓人了解。ToString returns a representation of the current exception that is intended to be understood by humans. 例外狀況包含區分文化特性的資料,所傳回的字串表示ToString需要納入考量目前系統文化特性。Where the exception contains culture-sensitive data, the string representation returned by ToString is required to take into account the current system culture. 雖然傳回之字串的格式沒有實際上的需求,但它應該嘗試反映做使用者察覺到物件的值。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.

預設實作ToString取得擲回目前例外狀況、 訊息、 呼叫的類別名稱ToString上的內部例外狀況,並呼叫Environment.StackTraceThe 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. 如果有任何這些成員是null,其值不包含在傳回的字串。If any of these members is null, its value is not included in the returned string.

如果沒有任何錯誤訊息,或者它是空字串 (""),則會不傳回任何錯誤訊息。If there is no error message or if it is an empty string (""), then no error message is returned. 如果它們不是,會傳回內部例外狀況和堆疊追蹤的名稱nullThe name of the inner exception and the stack trace are returned only if they are not null.

這個方法覆寫 Object.ToStringThis method overrides Object.ToString.

適用於