Exception.InnerException 屬性

定義

命名空間:

System

組件:

System.Runtime.dll

組件:

mscorlib.dll

組件:

netstandard.dll

取得造成目前例外狀況的 Exception 執行個體。

public:
 property Exception ^ InnerException { Exception ^ get(); };

public Exception InnerException { get; }

public Exception? InnerException { get; }

member this.InnerException : Exception

Public ReadOnly Property InnerException As Exception

屬性值

Exception

物件，描述造成目前例外狀況的錯誤。 InnerException 屬性會傳回與傳遞到 Exception(String, Exception) 建構函式中相同的值；如果沒有提供內部例外狀況值給建構函式，則傳回 null。 這個屬性是唯讀的。

實作

InnerException

範例

下列範例示範擲回和攔截參考內部例外狀況的例外狀況。

using namespace System;

public ref class AppException: public Exception
{
public:
   AppException(String^ message ) : Exception(message)
   {}

   AppException(String^ message, Exception^ inner) : Exception(message, inner)
   {}
};

public ref class Example
{
public:
   void ThrowInner()
   {
      throw gcnew AppException("Exception in ThrowInner method.");
   }

   void CatchInner()
   {
      try {
         this->ThrowInner();
      }
      catch (AppException^ e) {
         throw gcnew AppException("Error in CatchInner caused by calling the ThrowInner method.", e);
      }
   }
};

int main()
{
   Example^ ex = gcnew Example();
   try {
      ex->CatchInner();
   }
   catch (AppException^ e) {
      Console::WriteLine("In catch block of Main method.");
      Console::WriteLine("Caught: {0}", e->Message);
      if (e->InnerException != nullptr)
         Console::WriteLine("Inner exception: {0}", e->InnerException);
   }
}
// The example displays the following output:
//    In catch block of Main method.
//    Caught: Error in CatchInner caused by calling the ThrowInner method.
//    Inner exception: AppException: Exception in ThrowInner method.
//       at Example.ThrowInner()
//       at Example.CatchInner()

using System;

public class AppException : Exception
{
   public AppException(String message) : base (message)
   {}

   public AppException(String message, Exception inner) : base(message,inner) {}
}

public class Example
{
   public static void Main()
   {
      Example ex = new Example();

      try {
         ex.CatchInner();
      }
      catch(AppException e) {
         Console.WriteLine ("In catch block of Main method.");
         Console.WriteLine("Caught: {0}", e.Message);
         if (e.InnerException != null)
            Console.WriteLine("Inner exception: {0}", e.InnerException);
      }
   }

   public void ThrowInner ()
   {
      throw new AppException("Exception in ThrowInner method.");
   }

   public void CatchInner()
   {
      try {
         this.ThrowInner();
      }
      catch (AppException e) {
         throw new AppException("Error in CatchInner caused by calling the ThrowInner method.", e);
      }
   }
}
// The example displays the following output:
//    In catch block of Main method.
//    Caught: Error in CatchInner caused by calling the ThrowInner method.
//    Inner exception: AppException: Exception in ThrowInner method.
//       at Example.ThrowInner()
//       at Example.CatchInner()

open System

type AppException =
    inherit Exception
    
    new (message: string) = { inherit Exception(message) }

    new (message: string, inner) = { inherit Exception(message, inner) }

let throwInner () =
    raise (AppException "Exception in throwInner function.")
    ()

let catchInner () =
    try
        throwInner ()
    with :? AppException as e ->
        raise (AppException("Error in catchInner caused by calling the throwInner function.", e) )

[<EntryPoint>]
let main _ =
    try
        catchInner ()
    with :? AppException as e ->
        printfn "In with block of main function."
        printfn $"Caught: {e.Message}"
        if e.InnerException <> null then
            printfn $"Inner exception: {e.InnerException}"
    0
// The example displays the following output:
//    In with block of main function.
//    Caught: Error in catchInner caused by calling the throwInner function.
//    Inner exception: Example+AppException: Exception in throwInner function.
//       at Example.throwInner()
//       at Example.catchInner()

Public Class AppException : Inherits Exception
   Public Sub New(message As String)
      MyBase.New(message)
   End Sub
   
   Public Sub New(message As String, inner As Exception)
      MyBase.New(message, inner)
   End Sub
End Class

Public Class Example
   Public Shared Sub Main()
      Dim testInstance As New Example()
      Try
         testInstance.CatchInner()
      Catch e As AppException
         Console.WriteLine ("In catch block of Main method.")
         Console.WriteLine("Caught: {0}", e.Message)
         If e.InnerException IsNot Nothing Then
            Console.WriteLine("Inner exception: {0}", e.InnerException)
         End If
      End Try
   End Sub
   
   Public Sub ThrowInner()
      Throw New AppException("Exception in ThrowInner method.")
   End Sub
   
   Public Sub CatchInner()
      Try
         Me.ThrowInner()
      Catch e As AppException
         Throw New AppException("Error in CatchInner caused by calling the ThrowInner method.", e)
      End Try
   End Sub
End Class
' The example displays the following output:
'    In catch block of Main method.
'    Caught: Error in CatchInner caused by calling the ThrowInner method.
'    Inner exception: AppException: Exception in ThrowInner method.
'       at Example.ThrowInner()
'       at Example.CatchInner()

備註

當擲回例外 X 狀況做為先前例外 Y 狀況的直接結果時，的 InnerException X 屬性應該包含 的 Y 參考。

您可以使用 InnerException 屬性來取得造成目前例外狀況的例外狀況集合。

您可以建立攔截先前例外狀況的新例外狀況。 處理第二個例外狀況的程式碼可以使用先前例外狀況中的其他資訊，更適當地處理錯誤。

假設有一個函式會讀取檔案，並將該檔案中的資料格式化。 在此範例中，當程式碼嘗試讀取檔案時， IOException 會擲回 。 函式會 IOException 攔截 ，並擲回 FileNotFoundException 。 IOException可以儲存在 的 FileNotFoundException 屬性中 InnerException ，讓攔截 FileNotFoundException 的程式碼檢查初始錯誤的原因。

屬性 InnerException 會保留內部例外狀況的參考，會在初始化例外狀況物件時設定。