Elmah错误日志工具
Elmah可以以插件式的方式加入到项目中来，安装也非常方便。打开 视图>其它窗口>程序包管理控制台
第一步安装Elmah
安装：PM> Install-Package Elmah
这时候web.config文件就多出
<sectionGroup name="elmah"> <section name="security" requirePermission="false" type="Elmah.SecuritySectionHandler, Elmah" /> <section name="errorLog" requirePermission="false" type="Elmah.ErrorLogSectionHandler, Elmah" /> <section name="errorMail" requirePermission="false" type="Elmah.ErrorMailSectionHandler, Elmah" /> <section name="errorFilter" requirePermission="false" type="Elmah.ErrorFilterSectionHandler, Elmah" /> </sectionGroup>
<httpModules> <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" /> <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" /> <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" /> </httpModules>
<modules runAllManagedModulesForAllRequests="true"> <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" preCondition="managedHandler" /> <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" preCondition="managedHandler" /> <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" preCondition="managedHandler" /> </modules>
<elmah> <!-- See http://code.google.com/p/elmah/wiki/SecuringErrorLogPages for more information on remote access and securing ELMAH. --> <security allowRemoteAccess="false" /> <errorLog type="Elmah.OracleErrorLog, Elmah" connectionStringName="elmah-oracle" schemaOwner="" /> </elmah> <location path="elmah.axd" inheritInChildApplications="false"> <system.web> <httpHandlers> <add verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" /> </httpHandlers> <!-- See http://code.google.com/p/elmah/wiki/SecuringErrorLogPages for more information on using ASP.NET authorization securing ELMAH. <authorization> <allow roles="admin" /> <deny users="*" /> </authorization> --> </system.web> <system.webServer> <handlers> <add name="ELMAH" verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" preCondition="integratedMode" /> </handlers> </system.webServer> </location>
其中web节点，webserver节点分别是IIS6跟IIS7的区别
第二部安装Elmah.Oracle
安装：PM>Install-Package Elmah.Oracle
<connectionStrings> <!-- TODO: Replace the ****'s with the correct entries --> <add name="elmah-oracle" connectionString="Data Source=****;User ID=****;Password=****;" /> </connectionStrings>
创建Oracle上的数据表
/* ELMAH - Error Logging Modules and Handlers for ASP.NET Copyright (c) 2004-9 Atif Aziz. All rights reserved. Author(s): James Driscoll, mailto:jamesdriscoll@btinternet.com Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ -- $Id: Oracle.sql 568 2009-05-11 14:18:34Z azizatif $ -- NB This script assumes you have logged on in the schema where you want to create the ELMAH objects -- create a sequence for the errors (user to simulate an identity in SQL Server) CREATE SEQUENCE elmah$error_seq START WITH 1 INCREMENT BY 1 NOMAXVALUE NOCYCLE NOCACHE NOORDER; -- create the table to store the data -- you can optionally specify tablespaces here too! CREATE TABLE elmah$error ( -- if using Oracle 10g and above you can add DEFAULT SYS_GUID() -- to the errorid definition. -- Oracle 8i doesn't like it with an NVARCHAR2 -- haven't tested it against 9i errorid NVARCHAR2(32) NOT NULL, application NVARCHAR2(60) NOT NULL, host NVARCHAR2(30) NOT NULL, type NVARCHAR2(100) NOT NULL, source NVARCHAR2(60), message NVARCHAR2(500) NOT NULL, username NVARCHAR2(50), statuscode NUMBER NOT NULL, timeutc DATE NOT NULL, sequencenumber NUMBER NOT NULL, allxml NCLOB NOT NULL, CONSTRAINT idx_elmah$error_pk PRIMARY KEY (errorid) USING INDEX -- TABLESPACE "TABLESPACE FOR INDEX" ) -- TABLESPACE "TABLESPACE FOR DATA" / -- trigger to make sure we get our sequence number in the table CREATE TRIGGER trg_elmah$error_bi BEFORE INSERT ON elmah$error FOR EACH ROW BEGIN SELECT elmah$error_seq.NEXTVAL INTO :new.sequencenumber FROM dual; END trg_elmah$error_bi; / -- create the index on the table CREATE INDEX idx_elmah$error_app_time_seq ON elmah$error(application, timeutc DESC, sequencenumber DESC) / -- package containing the procedure we need for ELMAH to log errors CREATE OR REPLACE PACKAGE pkg_elmah$log_error IS PROCEDURE LogError ( v_ErrorId IN elmah$error.errorid%TYPE, v_Application IN elmah$error.application%TYPE, v_Host IN elmah$error.host%TYPE, v_Type IN elmah$error.type%TYPE, v_Source IN elmah$error.source%TYPE, v_Message IN elmah$error.message%TYPE, v_User IN elmah$error.username%TYPE, v_AllXml IN elmah$error.allxml%TYPE, v_StatusCode IN elmah$error.statuscode%TYPE, v_TimeUtc IN elmah$error.timeutc%TYPE ); END pkg_elmah$log_error; / CREATE OR REPLACE PACKAGE BODY pkg_elmah$log_error IS PROCEDURE LogError ( v_ErrorId IN elmah$error.errorid%TYPE, v_Application IN elmah$error.application%TYPE, v_Host IN elmah$error.host%TYPE, v_Type IN elmah$error.type%TYPE, v_Source IN elmah$error.source%TYPE, v_Message IN elmah$error.message%TYPE, v_User IN elmah$error.username%TYPE, v_AllXml IN elmah$error.allxml%TYPE, v_StatusCode IN elmah$error.statuscode%TYPE, v_TimeUtc IN elmah$error.timeutc%TYPE ) IS BEGIN INSERT INTO elmah$error ( errorid, application, host, type, source, message, username, allxml, statuscode, timeutc ) VALUES ( UPPER(v_ErrorId), v_Application, v_Host, v_Type, v_Source, v_Message, v_User, v_AllXml, v_StatusCode, v_TimeUtc ); END LogError; END pkg_elmah$log_error; / -- package containing the procedure we need for ELMAH to retrieve errors CREATE OR REPLACE PACKAGE pkg_elmah$get_error IS -- NB this is for backwards compatibility with Oracle 8i TYPE t_cursor IS REF CURSOR; PROCEDURE GetErrorXml ( v_Application IN elmah$error.application%TYPE, v_ErrorId IN elmah$error.errorid%TYPE, v_AllXml OUT elmah$error.allxml%TYPE ); PROCEDURE GetErrorsXml ( v_Application IN elmah$error.application%TYPE, v_PageIndex IN NUMBER DEFAULT 0, v_PageSize IN NUMBER DEFAULT 15, v_TotalCount OUT NUMBER, v_Results OUT t_cursor ); END pkg_elmah$get_error; / CREATE OR REPLACE PACKAGE BODY pkg_elmah$get_error IS PROCEDURE GetErrorXml ( v_Application IN elmah$error.application%TYPE, v_ErrorId IN elmah$error.errorid%TYPE, v_AllXml OUT elmah$error.allxml%TYPE ) IS BEGIN SELECT allxml INTO v_AllXml FROM elmah$error WHERE errorid = UPPER(v_ErrorId) AND application = v_Application; EXCEPTION WHEN NO_DATA_FOUND THEN v_AllXml := NULL; END GetErrorXml; PROCEDURE GetErrorsXml ( v_Application IN elmah$error.application%TYPE, v_PageIndex IN NUMBER DEFAULT 0, v_PageSize IN NUMBER DEFAULT 15, v_TotalCount OUT NUMBER, v_Results OUT t_cursor ) IS l_StartRowIndex NUMBER; l_EndRowIndex NUMBER; BEGIN -- Get the ID of the first error for the requested page l_StartRowIndex := v_PageIndex * v_PageSize + 1; l_EndRowIndex := l_StartRowIndex + v_PageSize - 1; -- find out how many rows we've got in total SELECT COUNT(*) INTO v_TotalCount FROM elmah$error WHERE application = v_Application; OPEN v_Results FOR SELECT * FROM ( SELECT e.*, ROWNUM row_number FROM ( SELECT /*+ INDEX(elmah$error, idx_elmah$error_app_time_seq) */ errorid, application, host, type, source, message, username, statuscode, timeutc FROM elmah$error WHERE application = v_Application ORDER BY timeutc DESC, sequencenumber DESC ) e WHERE ROWNUM <= l_EndRowIndex ) WHERE row_number >= l_StartRowIndex; END GetErrorsXml; END pkg_elmah$get_error; / /* -- If you are securing the packages above, you will need to grant execute -- privileges on them so that they can be called by the user connecting to the database. -- NB As long as you use the schema owner for the connection string, this is not necessary, -- although this is generally discouraged by Best Practices. -- Option 1) Allow any user to execute the package (not recommended) -- replace OWNER for the schema owner in the following statement GRANT EXECUTE ON OWNER.pkg_elmah$log_error TO PUBLIC; GRANT EXECUTE ON OWNER.pkg_elmah$get_error TO PUBLIC; -- Option 2) Allow a single user to execute the package (better) -- replace OWNER for the schema owner in the following statement GRANT EXECUTE ON OWNER.pkg_elmah$log_error TO USER_NAME; GRANT EXECUTE ON OWNER.pkg_elmah$get_error TO USER_NAME; -- Option 3) Lock things down so that one user can only log errors, while another user can read and log errors (most secure) -- replace OWNER for the schema owner in the following statement -- LOGGING_USER_NAME will be used to connect to the database in all sites which log errors to the database GRANT EXECUTE ON OWNER.pkg_elmah$log_error TO LOGGING_USER_NAME; -- ADMIN_USER_NAME will be used to connect to the database in an admin portal which allows users to read errors GRANT EXECUTE ON OWNER.pkg_elmah$log_error TO ADMIN_USER_NAME; GRANT EXECUTE ON OWNER.pkg_elmah$get_error TO ADMIN_USER_NAME; -- NB if you do take this approach, be sure to set the schemaOwner parameter in your web.config */
输入上面的命令安装成功之后，在程序里随便抛出一个异常，就可以通过地址 http://localhost:XXXX/elmah.axd 来查看错误信息。如图：
详情：
看看Oracle创建的表，如图
如果异常通过catch被捕获了就无法记录了，除非捕获后又throw。也就是在异常链上，最终的异常必须抛给了ASP.NET运行时，才可以被捕获
所以try,catch,在catch处记录日志则调用此方法：
public static Log(Exception e)
{
var context = HttpContext.Current;
if (context == null)
return ;
var signal = ErrorSignal.FromContext(context);
if (signal == null)
return ;
signal.Raise(e, context);
}