Asp. NET common 33 kinds of practical code

1. Open a new window and transfer parameters:

Transfer parameters:

Response.Write ("")

Receive parameters:

String a = Request.QueryString ("id");
String B = Request.QueryString ("Id1");

2. Add a dialog box for the button

BUTTON1.ATTRIBUTES.ADD ("onclick", "return confirm (' Confirm? ')");
Button.attributes.add ("onclick", "If" (Confirm (' Are you sure ...? ')) {return true;} Else{return false;} ")

3. Delete table Selected records

int intempid = (int) Mydatagrid.datakeys[e.item.itemindex];
String deletecmd = "DELETE from Employee where emp_id =" + intempid.tostring ()

4. Delete the form record warning

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" (' You are sure you want to delete this message '); ");
Break
Default
Break
}

}

5. Click on a table row link another page

private void Grdcustomer_itemdatabound (object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
Click on the form to open
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 + "');
}

Double-click a table to connect to another page

In the ItemDataBind event

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 +" "");
}

Double-click a table to open a new page

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 +" ")";
}

★ Special attention: "? id=" Can not be "? id ="

6. Table super Join column pass parameter

<%# DataBinder.Eval (Container.DataItem, data field 1)%> ' & Name= ' <%# DataBinder.Eval (Container.DataItem, "data field 2")%> '/ >

7. Click to change the color of the form

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 ';
}

Written in the _itemdatabound of the DataGrid.

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. About date formats

Date format setting

Dataformatstring= "{0:YYYY-MM-DD}"

I think it should be in the Itembound incident.

e.items.cell["Your column"].text=datetime.parse (e.items.cell["Your column"].text. ToString ("Yyyy-mm-dd"))

9. Get the error message and go to the specified page

Instead of using Response.Redirect, you should use Server.Transfer

e.g

In Global.asax
protected void Application_Error (Object sender, EventArgs e) {
if (Server.GetLastError () is httpunhandledexception)
Server.Transfer ("myerrorpage.aspx");

The rest of the httpunhandledexception exception to ASP.net to deal with their own okay the:)
}

REDIRECT can cause Post-back to lose error messages, so page orientation should be done directly on the server side, so that you can get error messages on the error-handling page and handle them accordingly.

10. Empty Cookies

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

11. Custom Exception Handling

Custom Exception Handling Classes
Using System;
Using System.Diagnostics;

Namespace Myappexception
{
<summary>
ApplicationException an inherited application exception handling class from the system exception class.
Automatically logs exception content to the Windows nt/2000 Application log
</summary>
public class AppException:System.ApplicationException
{
Public Appexception ()
{
if (applicationconfiguration.eventlogenabled) LogEvent ("An unknown error occurred.") ");
}

Public appexception (String message)
{
LogEvent (message);
}

Public appexception (String message,exception innerexception)
{
LogEvent (message);
if (innerexception!= null)
{
LogEvent (Innerexception.message);
}
}

Logging class
Using System;
Using System.Configuration;
Using System.Diagnostics;
Using System.IO;
Using System.Text;
Using System.Threading;

Namespace MyEventLog
{
<summary>
Event logging classes, providing event logging support
<remarks>
Defines 4 logging methods (Error, warning, info, trace)
</remarks>
</summary>
public class Applicationlog
{
<summary>
Log error messages to the Win2000/nt event log
<param name= "Message" The text information you need to record </param>
</summary>
public static void Writeerror (String message)
{
Writelog (tracelevel.error, message);
}

<summary>
Log warning messages to the Win2000/nt event log
<param name= "Message" The text information you need to record </param>
</summary>
public static void Writewarning (String message)
{
Writelog (tracelevel.warning, message);
}

<summary>
To log a hint to the Win2000/nt event log
<param name= "Message" The text information you need to record </param>
</summary>
public static void Writeinfo (String message)
{
Writelog (tracelevel.info, message);
}
<summary>
Log trace information to the Win2000/nt event log
<param name= "Message" The text information you need to record </param>
</summary>
public static void Writetrace (String message)
{
Writelog (tracelevel.verbose, message);
}

<summary>
Format text information that is logged to the event log
<param name= "Ex" the exception object that needs to be formatted </param>
<param name= "Catchinfo" > exception message header string. </param>
<retvalue>
The <para> the formatted exception information string, including the exception content and the trace stack. </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>
Actual Event Log Write method
<param name= the level of information to be recorded (Error,warning,info,trace). </param>
<param name= "MessageText" > text to be recorded. </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);
Writing to the event log
EventLog.WriteEntry (MessageText, Logentrytype);

}
Catch {}//ignore any exceptions
}
}//class Applicationlog
}

12.Panel horizontal scrolling, vertical automatic expansion

13. Return to Tab

14.DataGrid Super Connection column

datanavigateurlfield= "field name" Datanavigateurlformatstring= "http://xx/inc/delete.aspx?id={0}"

15.DataGrid line changes color with mouse

private void Dgzf_itemdatabound (object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
if (E.item.itemtype!=listitemtype.header)
{
E.item.attributes.add ("onmouseout", "this.style.backgroundcolor=\" "+e.item.style[" Background-color "]+" "");
E.item.attributes.add ("onmouseover", "this.style.backgroundcolor=\" "+" #EFF3F7 "+" ");
}
}

16. Template columns

Background code

protected void Checkall_checkedchanged (object sender, System.EventArgs e)
{
Change the selection of columns to achieve either a full or a full selection.
CheckBox Chkexport;
if (checkall.checked)
{
foreach (DataGridItem odatagriditem in Mydatagrid.items)
{
Chkexport = (checkbox) Odatagriditem.findcontrol ("Chkexport");
Chkexport.checked = true;
}
}
Else
{
foreach (DataGridItem odatagriditem in Mydatagrid.items)
{
Chkexport = (checkbox) Odatagriditem.findcontrol ("Chkexport");
chkexport.checked = false;
}
}
}

17. Number format

"<% #Container. DataItem (" price ")%> result is 500.0000, how to format into 500.00?"

<% #Container. DataItem ("Price", "{0:￥#,# #0.00}")%>

int i=123456;
String s=i.tostring ("###,###.00");