Asp.net is a very useful statement from to 26

21. Custom Exception Handling

// Custom exception handling class
Using system;
Using system. diagnostics;
Namespace myappexception
{
/// <Summary>
/// Application exception handling class inherited from the system exception class applicationexception.
/// Automatically record the exception content to the application logs of Windows NT/2000
/// </Summary>
Public class appexception: system. applicationexception
{
Public appexception ()
{
If (applicationconfiguration. eventlogenabled) logevent (& quot; an unknown error occurs. & Quot ;);
}
Public appexception (string message)
{
Logevent (Message );
}
Public appexception (string message, exception innerexception)
{
Logevent (Message );
If (innerexception! = NULL)
{
Logevent (innerexception. Message );
}
}
// Log record type
Using system;
Using system. configuration;
Using system. diagnostics;
Using system. IO;
Using system. text;
Using system. Threading;
Namespace myeventlog
{
/// <Summary>
/// Event logging class, supporting event logging
/// <Remarks>
/// Defines four logging methods (error, warning, info, trace)
/// </Remarks>
/// </Summary>
Public class applicationlog
{
/// <Summary>
/// Record the error information to the Win2000/NT Event Log
/// <Param name = & quot; message & quot;> text information to be recorded </param>
/// </Summary>
Public static void writeerror (string message)
{
Writelog (tracelevel. error, message );
}
/// <Summary>
/// Record the warning information to the Win2000/NT Event Log
/// <Param name = & quot; message & quot;> text information to be recorded </param>
/// </Summary>
Public static void writewarning (string message)
{
Writelog (tracelevel. Warning, message );
}
/// <Summary>
/// Record the prompt information to the Win2000/NT Event Log
/// <Param name = & quot; message & quot;> text information to be recorded </param>
/// </Summary>
Public static void writeinfo (string message)
{
Writelog (tracelevel. info, message );
}
/// <Summary>
/// Record tracking information to Win2000/NT Event Logs
/// <Param name = & quot; message & quot;> text information to be recorded </param>
/// </Summary>
Public static void writetrace (string message)
{
Writelog (tracelevel. verbose, message );
}
/// <Summary>
/// Format the text information recorded in the event log
/// <Param name = & quot; Ex & quot;> the exception object to be formatted </param>
/// <Param name = & quot; catchinfo & quot;> exception message title string. </param>
/// <Retvalue>
/// <Para> formatted exception information string, including the exception content and 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 (& quot;/R/N & quot ;);
}
Strbuilder. append (ex. Message). append (& quot;/R/N & quot;). append (ex. stacktrace );
Return strbuilder. tostring ();
}
/// <Summary>
/// Actual event log Writing Method
/// <Param name = & quot; level & quot;> level of the information to be recorded (error, warning, info, trace). </param>
/// <Param name = & quot; messagetext & quot;> 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 = new EventLog (& quot; Application & quot;, applicationconfiguration. eventlogmachinename, applicationconfiguration. eventlogsourcename );
// Write Event Logs
EventLog. writeentry (messagetext, logentrytype );
}
Catch {} // ignore any exceptions
}
} // Class applicationlog
}

22. horizontal panel scrolling and vertical auto Scaling

<Asp: Panel style = & quot; overflow-X: Scroll; overflow-Y: auto; & quot;> </ASP: Panel>

23. Press enter to convert to Tab
(1)

<Script language = & quot; JavaScript & quot; For = & quot; Document & quot; event = & quot; onkeydown & quot;>
If (event. keycode = 13 & amp; event. srcelement. type! = 'Button '& amp; event. srcelement. type! = 'Submit '& amp; event. srcelement. type! = 'Reset' & amp; event. srcelement. type! = ''& Amp; event. srcelement. type! = 'Textea ');
Event. keycode = 9;
</SCRIPT>

(2) // when you press enter on a control with a keydown event, it becomes a tab.

Public void tab (system. Web. UI. webcontrols. webcontrol)
{
Webcontrol. Attributes. Add (& quot; onkeydown & quot;, & quot; If (event. keycode = 13) event. keycode = 9 & quot ;);
}
24. DataGrid super join Column
Datanavigateurlfield = & quot; field name & quot; datanavigateurlformatstring = & quot; http: // XX/INC/Delete. aspx? Id = {0} & quot;

25. The row of the DataGrid changes color with the mouse

Private void dgzf_itemdatabound (Object sender, system. Web. UI. webcontrols. datagriditemeventargs E)
{
If (E. Item. itemtype! = Listitemtype. header)
{
E. item. attributes. add (& quot; onmouseout & quot;, & quot; this. style. backgroundcolor =/& quot; + E. item. style [& quot; Background-color & quot;] + & quot;/& quot ;);
E. item. attributes. add (& quot; onmouseover & quot;, & quot; this. style. backgroundcolor =/& quot; + & quot; # eff3f7 & quot; + & quot;/& quot ;);
}
}

26. template Column

<Asp: templatecolumn visible = & quot; false & quot; sortexpression = & quot; demo & quot;

Headertext = & quot; Id & quot;>
<Itemtemplate>
<Asp label text = '<% # databinder. eval (container. dataitem,

& Quot; ArticleID & quot;) %> 'runat = & quot; server & quot; width = & quot; 80% & quot;

Id = & quot; lblcolumn & quot;/>
</Itemtemplate>
</ASP: templatecolumn>
<Asp: templatecolumn headertext = & quot; Selected & quot;>
<Headerstyle wrap = & quot; false & quot; horiz> <Itemtemplate>
<Asp: checkbox id = & quot; chkexport & quot; runat = & quot; server & quot;/>
</Itemtemplate>
<Edititemtemplate>
<Asp: checkbox id = & quot; chkexporton & quot; runat = & quot; server & quot;

Enabled = & quot; true & quot;/>
</Edititemtemplate>
</ASP: templatecolumn>

Background code

Protected void checkall_checkedchanged (Object sender, system. eventargs E)
{
// Change the column selection to select all or all columns.
Checkbox chkexport;
If (checkall. Checked)
{
Foreach (maid in mydatagrid. Items)
{
Chkexport = (checkbox) odatagriditem. findcontrol (& quot; chkexport & quot ;);
Chkexport. Checked = true;
}
}
Else
{
Foreach (maid in mydatagrid. Items)
{
Chkexport = (checkbox) odatagriditem. findcontrol (& quot; chkexport & quot ;);
Chkexport. Checked = false;
}
}
}