正在阅读：用简单的Tracer类来为应用写入跟踪用简单的Tracer类来为应用写入跟踪

    TFileLog = class(TInterfacedObject, IOutput)
    private
        FLogFile: string;
    public
        constructor Create(const FileName: string);
        procedure Write(const aInfo: ITraceInfo); //写入跟踪信息
    end;

    TProcStr = procedure(const value:string) of Object;
    TDatabaseLog = class(TInterfacedObject, IOutput)
    private
        FWriteProc :TProcStr;
    public
        constructor Create(WriteProc: TProcStr);
        procedure Write(const aInfo: ITraceInfo); //写入跟踪信息
    end;

//==========================
// 跟踪工具
//==========================

{ TTracer }
    //用来进行记录跟踪日志的类
    TTracer = class(TObject)
    private
        FOutput: IOutput; //输出目标
        procedure SetOutput(const Value: IOutput);
    public
        constructor Create; overload;
        constructor Create(aOutput: IOutput); overload;
        destructor Destroy; override;
        property Output: IOutput read FOutput write SetOutput;
        procedure Write(const aInfo: ITraceInfo); //写入跟踪信息
    end;

implementation

{ TTracer }

constructor TTracer.Create;
begin

end;

constructor TTracer.Create(aOutput: IOutput);
begin
    FOutput := aOutput;
end;