ASP.NET 常用的程式碼(ㄧ)

摘自: skyline0217 ASP.NET程式中常用的33種程式碼

1. 打開新的視窗並傳送參數:
傳送參數:

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

 接收參數:

    protected void Page_Load(object sender, EventArgs e)
    {
        sCLINIC_DATE = Context.Request.QueryString["CLINIC_DATE"];
        sID_NO = Context.Request.QueryString["ID_NO"];
    }        

2.為按鈕新增對話方塊

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

 3.刪除表格指定紀錄


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

4.刪除表格紀錄警告 


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(’您是否確定要刪除這條資訊’);");
   break;
  default:
   break;
 }
}

5.點擊表格行連結另一頁 

private void grdCustomer_ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
 //點擊表格打開
 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 + "’);");
}

雙擊表格連接到另一頁
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 + "’");
}

雙擊表格另開新頁 

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 + "’)");
}

6.表格超連結列傳遞參數

<asp:HyperLinkColumn Target="_blank" headertext="ID號" DataTextField="id" NavigateUrl="aaa.aspx?id=’
 <%# DataBinder.Eval(Container.DataItem, "數據欄位1")%>’ & name=’<%# DataBinder.Eval(Container.DataItem, "數據欄位2")%>’ />

 7.表格點擊改變顏色

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’;");
}

寫在DataGrid的_ItemDataBound裏


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.關於日期格式
日期格式設定 

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

我覺得應該在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.獲取錯誤資訊並到指定頁面
不要使用Response.Redirect,而應該使用Server.Transfer   e.g

// in global.asax
protected void Application_Error(Object sender, EventArgs e) {
if (Server.GetLastError() is HttpUnhandledException)
Server.Transfer("MyErrorPage.aspx");
//其餘的非HttpUnhandledExceptionException交給ASP.NET自己處理就okay了 :)
}

Redirect會導致post-back的產生從而丟失了錯誤資訊,所以頁面導向應該直接在伺服器端執行,這樣就可以在錯誤處理頁面得到出錯資訊並進行相應的處理  

10.清空Cookie


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

 11.自定義Exception處理

//自定義Exception處理類別
using System;
using System.Diagnostics;
namespace MyAppException
{
 /// <summary>
 /// 從系統Exception類別ApplicationException繼承的應用程式Exception處理類別。
 /// 自動將Exception內容紀錄到Windows NT/2000的應用程式日誌
 /// </summary>
 public class AppException:System.ApplicationException
 {
  public AppException()
  {
   if (ApplicationConfiguration.EventLogEnabled)LogEvent("出現一個未知錯誤。");
  }
 public AppException(string message)
 {
  LogEvent(message);
 }
 public AppException(string message,Exception innerException)
 {
  LogEvent(message);
  if (innerException != null)
  {
   LogEvent(innerException.Message);
  }
 }
 //日誌紀錄類別
 using System;
 using System.Configuration;
 using System.Diagnostics;
 using System.IO;
 using System.Text;
 using System.Threading;
 namespace MyEventLog
 {
  /// <summary>
  /// 事件日誌紀錄類別,提供事件日誌紀錄支援
  /// <remarks>
  /// 定義了4個日誌紀錄方法 (error, warning, info, trace)
  /// </remarks>
  /// </summary>
  public class ApplicationLog
  {
   /// <summary>
   /// 將錯誤資訊紀錄到Win2000/NT事件日誌中
   /// <param name="message">需要紀錄的文件資訊</param>
   /// </summary>
   public static void WriteError(String message)
   {
    WriteLog(TraceLevel.Error, message);
   }
   /// <summary>
   /// 將警告資訊紀錄到Win2000/NT事件日誌中
   /// <param name="message">需要紀錄的文件資訊</param>
   /// </summary>
   public static void WriteWarning(String message)
   {
    WriteLog(TraceLevel.Warning, message);  
   }
   /// <summary>
   /// 將提示資訊紀錄到Win2000/NT事件日誌中
   /// <param name="message">需要紀錄的文件資訊</param>
   /// </summary>
   public static void WriteInfo(String message)
   {
    WriteLog(TraceLevel.Info, message);
   }
   /// <summary>
   /// 將Trace資訊紀錄到Win2000/NT事件日誌中
   /// <param name="message">需要紀錄的文件資訊</param>
   /// </summary>
   public static void WriteTrace(String message)
   {
    WriteLog(TraceLevel.Verbose, message);
   }
   /// <summary>
   /// 格式化紀錄到事件日誌的文件資訊格式
   /// <param name="ex">需要格式化的Exception物件</param>
   /// <param name="catchInfo">Exception資訊標題字串.</param>
   /// <retvalue>
   /// <para>格式後的Exception資訊字串,包括Exception內容和TraceStack.</para>
   /// </retvalue>
   /// </summary>
   public static String FormatException(Exception ex, String catchInfo)
   {
    StringBuilder strBuilder = new StringBuilder();
    if (catchInfo != String.Empty)
    {
     strBuilder.Append(catchInfo).Append("rn");
    }
    strBuilder.Append(ex.Message).Append("rn").Append(ex.StackTrace);
    return strBuilder.ToString();
   }
   /// <summary>
   /// 實際事件日誌寫入方法
   /// <param name="level">要紀錄資訊的級別(error,warning,info,trace).</param>
   /// <param name="messageText">要紀錄的文件.</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 );
     //寫入事件日誌
     eventLog.WriteEntry(messageText, LogEntryType);
    }
   catch {} //忽略任何Exception
  }
 } //class ApplicationLog
}