ASP.Net开发常见问题(1)

1. 打开新的窗口并传送参数：

传送参数：

response.write("<script>window.open
('*.aspx?id="+this.DropDownList1.SelectIndex+"&id1="+...+"')</script>")

 

接收参数：
string a  = Request.QueryString("id");
string b  = Request.QueryString("id1");

 

2.为按钮添加对话框

 

Button1.Attributes.Add("onclick","return confirm('确认?')");
button.attributes.add("onclick","if(confirm('are you sure...?'))
{return true;}else{return false;}")

 

 

3.删除表格选定记录

int intEmpID = (int)MyDataGrid.DataKeys[e.Item.ItemIndex];
string deleteCmd = "DELETE from Employee where emp_id = " + intEmpID.ToString()

 

 

4.删除表格记录警告

private void DataGrid_ItemCreated(Object sender,DataGridItemEventArgs e)
{
switch(e.Item.ItemType)
{
case ListItemType.Item :
case ListItemType.AlternatingItem :
case ListItemType.EditItem:
TableCell myTableCell;
myTableCell = e.Item.Cells[14];
LinkButton myDeleteButton ;
myDeleteButton = (LinkButton)myTableCell.Controls[0];
myDeleteButton.Attributes.Add
("onclick","return confirm('您是否确定要删除这条信息');");
break;
default:
break;
}
}

 

5.点击表格行链接另一页

private void grdCustomer_ItemDataBound
(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
//点击表格打开
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
e.Item.Attributes.Add("onclick","window.open
('Default.aspx?id=" + e.Item.Cells[0].Text + "');");
}

双击表格连接到另一页，在itemDataBind事件中

if(e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
string OrderItemID =e.item.cells[1].Text;
...
e.item.Attributes.Add("ondblclick", 
"location.href='../ShippedGrid.aspx?id=" + OrderItemID + "'");
}

双击表格打开新一页

if(e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
string OrderItemID =e.item.cells[1].Text;
...
e.item.Attributes.Add("ondblclick", 
"open('../ShippedGrid.aspx?id=" + OrderItemID + "')");
}

★特别注意：【?id=】 处不能为 【?id =】

 

6.表格超连接列传递参数

 

<asp:HyperLinkColumn Target="_blank"  headertext="ID号" DataTextField="id" 
NavigateUrl="aaa.aspx?id='<%# DataBinder.Eval(Container.DataItem, "数据字段1")%>'
& name='<%# DataBinder.Eval(Container.DataItem, "数据字段2")%>' />

 

7.表格点击改变颜色

if (e.Item.ItemType == ListItemType.Item ||e.Item.ItemType == ListItemType.AlternatingItem)
{
e.Item.Attributes.Add("onclick","this.style.backgroundColor='#99cc00';
this.style.color='buttontext';this.style.cursor='default';");
}

写在DataGrid的_ItemDataBound里

if (e.Item.ItemType == ListItemType.Item ||e.Item.ItemType == ListItemType.AlternatingItem)
{
e.Item.Attributes.Add("onmouseover","this.style.backgroundColor='#99cc00';
this.style.color='buttontext';this.style.cursor='default';");
e.Item.Attributes.Add("onmouseout","this.style.backgroundColor='';this.style.color='';");
}

 

8.关于日期格式

 

日期格式设定

DataFormatString="{0:yyyy-MM-dd}"

我觉得应该在itembound事件中

e.items.cell["你的列"].text=DateTime.Parse(e.items.cell["你的列"].text.ToString("yyyy-MM-dd"))

 

9.获取错误信息并到指定页面

不要使用Response.Redirect,而应该使用Server.Transfer

e.g

// in global.asax
protected void Application_Error(Object sender, EventArgs e) {
if (Server.GetLastError() is HttpUnhandledException)
Server.Transfer("MyErrorPage.aspx");

//其余的非HttpUnhandledException异常交给ASP.NET自己处理就okay了 :)
}

Redirect会导致post－back的产生从而丢失了错误信息，所以页面导向应该直接在服务器端执行，这样就可以在错误处理页面得到出错信息并进行相应的处理

 

10.清空Cookie

Cookie.Expires=[DateTime];
Response.Cookies("UserName").Expires = 0

 

11.自定义异常处理

//自定义异常处理类 
using System;
using System.Diagnostics;
namespace MyAppException
{
/// <summary>
/// 从系统异常类ApplicationException继承的应用程序异常处理类。
/// 自动将异常内容记录到Windows NT/2000的应用程序日志
/// </summary>
public class AppException:System.ApplicationException
{
public AppException()
{
if (ApplicationConfiguration.EventLogEnabled)
LogEvent("出现一个未知错误。");
}
public AppException(string message)
{
LogEvent(message);
}
public AppException(string message,Exception innerException)
{
LogEvent(message);
if (innerException != null)
{
LogEvent(innerException.Message);
}
}
//日志记录类
using System;
using System.Configuration;
using System.Diagnostics;
using System.IO;
using System.Text;
using System.Threading;
namespace MyEventLog
{
/// <summary>
///     事件日志记录类，提供事件日志记录支持 
///     <remarks>
///         定义了4个日志记录方法 (error, warning, info, trace) 
///     </remarks>
/// </summary>
public class ApplicationLog
{
/// <summary>
///     将错误信息记录到Win2000/NT事件日志中
///     <param name="message">需要记录的文本信息</param>
/// </summary>
public static void WriteError(String message)
{

WriteLog(TraceLevel.Error, message);
}

/// <summary>
///     将警告信息记录到Win2000/NT事件日志中
///     <param name="message">需要记录的文本信息</param>
/// </summary>
public static void WriteWarning(String message)
{

WriteLog(TraceLevel.Warning, message);
}

/// <summary>
///     将提示信息记录到Win2000/NT事件日志中
///     <param name="message">需要记录的文本信息</param>
/// </summary>
public static void WriteInfo(String message)
{
WriteLog(TraceLevel.Info, message);
}
/// <summary>
///     将跟踪信息记录到Win2000/NT事件日志中
///     <param name="message">需要记录的文本信息</param>
/// </summary>
public static void WriteTrace(String message)
{

WriteLog(TraceLevel.Verbose, message);
}

/// <summary>
///    格式化记录到事件日志的文本信息格式
///     <param name="ex">需要格式化的异常对象</param>
///     <param name="catchInfo">异常信息标题字符串.</param>
///     <retvalue>
///         <para>格式后的异常信息字符串，包括异常内容和跟踪堆栈.</para>
///     </retvalue>
/// </summary>
public static String FormatException(Exception ex, String catchInfo)
{
StringBuilder strBuilder = new StringBuilder();
if (catchInfo != String.Empty)
{
strBuilder.Append(catchInfo).Append("\r\n");
}
strBuilder.Append(ex.Message).Append("\r\n").Append(ex.StackTrace);
return strBuilder.ToString();
}
/// <summary>
///     实际事件日志写入方法
///     <param name="level">要记录信息的级别（error,warning,info,trace).</param>
///     <param name="messageText">要记录的文本.</param>
/// </summary>
private static void WriteLog(TraceLevel level, String messageText)
{

try
{   
EventLogEntryType LogEntryType;
switch (level)
{
case TraceLevel.Error:
LogEntryType = EventLogEntryType.Error;
break;
case TraceLevel.Warning:
LogEntryType = EventLogEntryType.Warning;
break;
case TraceLevel.Info:
LogEntryType = EventLogEntryType.Information;
break;
case TraceLevel.Verbose:
LogEntryType = EventLogEntryType.SuccessAudit;
break;
default:
LogEntryType = EventLogEntryType.SuccessAudit;
break;
}

EventLog eventLog = new EventLog("Application", ApplicationConfiguration.EventLogMachineName,         ApplicationConfiguration.EventLogSourceName );
//写入事件日志
eventLog.WriteEntry(messageText, LogEntryType);

}
catch {} //忽略任何异常
}    
} //class ApplicationLog
}