如何记录源代码行导致异常并添加自定义信息？

Question

我们的应用程序使用JCL记录导致异常的源代码行,并且它运行良好.我用的是D2007.我有一个执行实际日志记录的TApplicationEvents.OnException事件.考虑一下:

function MyFunc: String;
begin
  // Codelines that may raise exception.
  // Call functions that also may raise exception  
end;

procedure ComplexFunc(aVariable: String);
begin
  // also here can it be exceptions....
  // Code here that is the cause of exception
end;

procedure foo;
var
  myVar: String;
begin
  myvar := MyFunc;
  ComplexFunc(myvar);  
end;

procedure TMainForm.ApplicationEvents1Exception(Sender: TObject; E: Exception);
begin
  LogLastException(E, 'Unhandled Exception (%s)', [E.Message], 20);
end;

我有3个方法和我的onException事件.LogLastException在发生异常时记录callstack.问题是我无法在没有松散导致异常的源代码的情况下向E.Message添加信息.假设它是ComplexFunc中引发异常的第二行.我还想记录myvar变量的值.所以我将代码更改为:

function MyFunc: String;
begin
  // Codelines that may raise exception.
  // Call functions that also may raise exception  
end;

procedure ComplexFunc(aVariable: String);
begin
  // also here can it be exceptions....
  // Code here that is the cause of exception
end;

procedure foo;
var
  myVar: String;
begin
  try
    myvar := MyFunc;
    ComplexFunc(myvar); 
  except
    on E: Exception do
      raise TException.CreateFmt('myvar = %s', [myvar]);
  end; 
end;

procedure TMainForm.ApplicationEvents1Exception(Sender: TObject; E: Exception);
begin
  LogLastException(E, 'Unhandled Exception (%s)', [E.Message], 20);
end;

现在记录了myvar的值,但是我放弃了异常的原始源代码.而是记录带有raise TException.CreateFmt的行.有关如何做到这两点的任何建议？

问候

Answer 1

除了Marjan Vennema的回答(我将遵循),你可以提出你的新异常并使它看起来像来自旧异常的地址.

except
  on E: Exception do
    raise Exception.CreateFmt('myvar = %s', [myvar]) at ExceptAddr;
end;