上一节我们讲了如何捕获异常和记录日志，这一节我们讲，没有捕获的或者忘记捕获的异常包括404错误等，我们统一处理这个异常。
这一讲是利用 Application_Error 捕获所有异常，全局的异常处理为了减少代码，统一异常处理，Application_Error位于Global.asax里面，
protected void Application_Error(object sender, EventArgs e)
当一个异常在调用堆栈中没有被处理，也没有被框架代码处理时，我们说这个异常未处理，它将被ASP.NET捕获
它将捕获所有 Application 级别的 UnhandleException 和 HttpException（比如：访问的页面不存在等）
总之，在这里处理的话，那么在页面中的所有 try/catch 处理都可以不要了,但是我们为了记录日志，在BLL层还是要try catch
对此未处理错误的处理方法是显示一个页面，列出该未处理异常的详细情况。
我们通过 Application_Error事件把错误写进对应的文件里面或者数据库中。
/// <summary> /// 全局的异常处理 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> protected void Application_Error(object sender, EventArgs e) { string s = HttpContext.Current.Request.Url.ToString(); HttpServerUtility server = HttpContext.Current.Server; if (server.GetLastError() != null) { Exception lastError = server.GetLastError(); // 此处进行异常记录，可以记录到数据库或文本，也可以使用其他日志记录组件。 ExceptionHander.WriteException(lastError); Application["LastError"] = lastError; int statusCode = HttpContext.Current.Response.StatusCode; string exceptionOperator = "/SysException/Error"; try { if (!String.IsNullOrEmpty(exceptionOperator)) { exceptionOperator = new System.Web.UI.Control().ResolveUrl(exceptionOperator); string url = string.Format("{0}?ErrorUrl={1}", exceptionOperator, server.UrlEncode(s)); string script = String.Format("<script language='javascript' type='text/javascript'>window.top.location='{0}';</script>", url); Response.Write(script); Response.End(); } } catch { } } }
嘿嘿，我创造了一个错误 Convert.ToInt16("dddd");下面是错误的显示页面
关于错误页面的制作在控制器SysExceptionController增加
public ActionResult Error() { BaseException ex = new BaseException(); return View(ex); }
添加BaseException类
public class BaseException { #region 变量 private string exceptionMessage; private string exceptionName; private string innerExceptionMessage; private string innerExceptionName; private bool isShow; private Exception outermostException; private string sourceErrorFile; private string sourceErrorRowID; private string stackInfo; private string targetSite; #endregion #region 属性 public string ErrorPageUrl { get { return this.GetExceptionUrl(); } } public Exception Exception { get { return (HttpContext.Current.Session["Exception"] as Exception); } private set { HttpContext.Current.Session["Exception"] = value; } } public string ExceptionMessage { get { return this.exceptionMessage; } private set { this.exceptionMessage = value; } } public string ExceptionName { get { return this.exceptionName; } private set { this.exceptionName = value; } } public string InnerExceptionMessage { get { return this.innerExceptionMessage; } private set { this.innerExceptionMessage = value; } } public string InnerExceptionName { get { return this.innerExceptionName; } private set { this.innerExceptionName = value; } } public bool IsShowStackInfo { get { return this.isShow; } private set { this.isShow = value; } } public string SourceErrorFile { get { return this.sourceErrorFile; } private set { this.sourceErrorFile = value; } } public string SourceErrorRowID { get { return this.sourceErrorRowID; } private set { this.sourceErrorRowID = value; } } public string StackInfo { get { return this.stackInfo; } private set { this.stackInfo = value; } } public string TargetSite { get { return this.targetSite; } private set { this.targetSite = value; } } #endregion public BaseException() { this.outermostException = null; this.exceptionName = null; this.exceptionMessage = null; this.innerExceptionName = null; this.innerExceptionMessage = null; this.targetSite = null; this.stackInfo = null; this.sourceErrorFile = null; this.sourceErrorRowID = null; this.isShow = false; try { this.Exception = HttpContext.Current.Application["LastError"] as Exception; if (this.Exception != null) { this.outermostException = this.Exception; if ((this.Exception is HttpUnhandledException) && (this.Exception.InnerException != null)) { this.Exception = this.Exception.InnerException; } this.ExceptionName = this.GetExceptionName(this.Exception); this.ExceptionMessage = this.GetExceptionMessage(this.Exception); if (this.Exception.InnerException != null) { this.InnerExceptionName = this.GetExceptionName(this.Exception.InnerException); this.InnerExceptionMessage = this.GetExceptionMessage(this.Exception.InnerException); } this.TargetSite = this.GetTargetSite(this.Exception); this.StackInfo = this.GetStackInfo(this.Exception); if ((this.outermostException is HttpUnhandledException) && (this.outermostException.InnerException != null)) { this.StackInfo = this.StackInfo + "\r\n<a href='#' onclick=\"if(document.getElementById('phidden').style.display=='none') document.getElementById('phidden').style.display='block'; else document.getElementById('phidden').style.display='none'; return false;\"><b>[" + this.outermostException.GetType().ToString() + "]</b></a>\r\n"; this.StackInfo = this.StackInfo + "<pre id='phidden' style='display:none;'>" + this.outermostException.StackTrace + "</pre>"; } this.SourceErrorFile = this.GetSourceErrorFile(); this.SourceErrorRowID = this.GetSourceErrorRowID(); this.IsShowStackInfo = true; } HttpContext.Current.Session["LastError"] = null; } catch (Exception exception) { this.ExceptionMessage = "异常基页出错" + exception.Message; } } #region 方法 private string GetExceptionMessage(Exception ex) { return ex.Message; } private string GetExceptionMessageForLog() { StringBuilder builder = new StringBuilder(50); builder.AppendFormat("<ExceptionName>{0}</ExceptionName>", this.ExceptionName); builder.AppendFormat("<ExceptionMessage>{0}</ExceptionMessage>", this.ExceptionMessage); builder.AppendFormat("<InnerExceptionName>{0}</InnerExceptionName>", this.InnerExceptionName); builder.AppendFormat("<InnerExceptionMessage>{0}</InnerExceptionMessage>", this.InnerExceptionMessage); builder.AppendFormat("<TargetSite>{0}</TargetSite>", this.TargetSite); builder.AppendFormat("<ErrorPageUrl>{0}</ErrorPageUrl>", this.ErrorPageUrl); builder.AppendFormat("<SourceErrorFile>{0}</SourceErrorFile>", this.SourceErrorFile); builder.AppendFormat("<SourceErrorRowID>{0}</SourceErrorRowID>", this.SourceErrorRowID); return builder.ToString(); } private string GetExceptionMessageForMail() { StringBuilder builder = new StringBuilder(50); builder.Append("<ExceptionInfo>"); builder.Append(this.GetExceptionMessageForLog()); builder.AppendFormat("<StackInfo><![CDATA[{0}]]></StackInfo>", this.StackInfo); builder.Append("</ExceptionInfo>"); return builder.ToString(); } private string GetExceptionName(Exception ex) { string str = null; if (ex != null) { str = ex.GetType().FullName; } return str; } private string GetExceptionUrl() { string str = null; if (HttpContext.Current.Request["ErrorUrl"] != null) { str = HttpContext.Current.Request["ErrorUrl"].ToString(); } return str; } private string GetSourceErrorFile() { string stackInfo = this.StackInfo; string[] strArray = new string[0]; if (stackInfo == null) { return stackInfo; } strArray = stackInfo.Split(new string[] { "位置", "行号" }, StringSplitOptions.RemoveEmptyEntries); if (strArray.Length >= 3) { stackInfo = strArray[1]; if (stackInfo.LastIndexOf(":") == (stackInfo.Length - 1)) { stackInfo = stackInfo.Substring(0, stackInfo.Length - 1); } return stackInfo; } return ""; } private string GetSourceErrorRowID() { string stackInfo = this.StackInfo; string[] strArray = new string[0]; if (stackInfo == null) { return stackInfo; } strArray = stackInfo.Split(new string[] { "行号" }, StringSplitOptions.RemoveEmptyEntries); if (strArray.Length >= 2) { stackInfo = strArray[1].Trim(); string[] strArray2 = stackInfo.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries); if (strArray2.Length >= 2) { stackInfo = strArray2[0]; } return stackInfo; } return ""; } private string GetStackInfo(Exception ex) { string str = null; if (ex != null) { str = "<b>[" + ex.GetType().ToString() + "]</b>\r\n" + ex.StackTrace; if (ex.InnerException != null) { str = this.GetStackInfo(ex.InnerException) + "\r\n" + str; } } return str; } private string GetTargetSite(Exception ex) { string str = null; if (ex != null) { ex = this.GetBenmostException(ex); MethodBase targetSite = ex.TargetSite; if (targetSite != null) { str = string.Format("{0}.{1}", targetSite.DeclaringType, targetSite.Name); } } return str; } protected Exception GetBenmostException(Exception ex) { while (true) { if (ex.InnerException != null) { ex = ex.InnerException; } else { return ex; } } } #endregion }