This document provides tips and best practices for developing .NET applications. It covers general best practices such as optimization of loops, proper object disposal, and avoiding unnecessary object instantiation. It also includes ASP.NET specific tips like disabling viewstate if not used and avoiding unnecessary round trips to the server. Windows Forms tips involve using multithreading properly and marshaling method calls to the correct thread. The document recommends using existing libraries and not reinventing functionality unnecessarily.

1. Tips and Tricks of Developing
.NET Application
Joni
Applied Technology Laboratories
Bina Nusantara University

2. Agenda
 General Best Practices
 ASP .NET Specific
 Windows Forms Specific
 Resources

3. General Best Practices
 Looping optimization
ArrayList list = new ArrayList();ArrayList list = new ArrayList();
for(int ifor(int i == 0; i0; i << list.Count; i++)list.Count; i++)
{{
MyObject o = (MyObject)list[i];MyObject o = (MyObject)list[i];
o.DoSomeWork();o.DoSomeWork();
}}
ArrayList list = new ArrayList();ArrayList list = new ArrayList();
MyObject oMyObject o = null;= null;
for(int ifor(int i == 00, n =, n = list.Count; ilist.Count; i << nn; i++); i++)
{{
o = (MyObject)list[i];o = (MyObject)list[i];
o.DoSomeWork();o.DoSomeWork();
}}

4. General Best Practices
 Use proper casting, avoid polymorphic call
String s = “Hello world”;String s = “Hello world”;
Session[“key”] = s;Session[“key”] = s;
……
String result = Session[“key”].ToString();String result = Session[“key”].ToString();
String s = “Hello world”;String s = “Hello world”;
Session[“key”] = s;Session[“key”] = s;
……
String result =String result = (string)(string)Session[“key”];Session[“key”];

5. General Best Practices
 Acquire, Execute, Release pattern
 Works with any IDisposable object
 Data access classes, streams, text readers and writers,
network classes, etc.
using (Resource res = new Resource()) {using (Resource res = new Resource()) {
res.DoWork();res.DoWork();
}}
Resource res = new Resource(...);Resource res = new Resource(...);
try {try {
res.DoWork();res.DoWork();
}}
finally {finally {
if (res != null) ((IDisposable)res).Dispose();if (res != null) ((IDisposable)res).Dispose();
}}

6. General Best Practices
static void Copy(string sourceName, string destName) {static void Copy(string sourceName, string destName) {
Stream input = File.OpenRead(sourceName);Stream input = File.OpenRead(sourceName);
Stream output = File.Create(destName);Stream output = File.Create(destName);
byte[] b = new byte[65536];byte[] b = new byte[65536];
int n;int n;
while ((n = input.Read(b, 0, b.Length)) != 0) {while ((n = input.Read(b, 0, b.Length)) != 0) {
output.Write(b, 0, n);output.Write(b, 0, n);
}}
output.Close();output.Close();
input.Close();input.Close();
}}
static void Copy(string sourceName, string destName) {static void Copy(string sourceName, string destName) {
Stream input = File.OpenRead(sourceName);Stream input = File.OpenRead(sourceName);
try {try {
Stream output = File.Create(destName);Stream output = File.Create(destName);
try {try {
byte[] b = new byte[65536];byte[] b = new byte[65536];
int n;int n;
while ((n = input.Read(b, 0, b.Length)) != 0) {while ((n = input.Read(b, 0, b.Length)) != 0) {
output.Write(b, 0, n);output.Write(b, 0, n);
}}
}}
finally {finally {
output.Close();output.Close();
}}
}}
finally {finally {
input.Close();input.Close();
}}
}}
static void Copy(string sourceName, string destName) {static void Copy(string sourceName, string destName) {
using (Stream input = File.OpenRead(sourceName))using (Stream input = File.OpenRead(sourceName))
using (Stream output = File.Create(destName)) {using (Stream output = File.Create(destName)) {
byte[] b = new byte[65536];byte[] b = new byte[65536];
int n;int n;
while ((n = input.Read(b, 0, b.Length)) != 0) {while ((n = input.Read(b, 0, b.Length)) != 0) {
output.Write(b, 0, n);output.Write(b, 0, n);
}}
}}
}}

7.  In time critical application, avoid using
‘foreach’
General Best Practices
public static void Main(string[] args) {public static void Main(string[] args) {
foreach (string s in args) Console.WriteLine(s);foreach (string s in args) Console.WriteLine(s);
}}
public static void Main(string[] args) {public static void Main(string[] args) {
for(int i = 0, n = args.Length; i < n; i++)for(int i = 0, n = args.Length; i < n; i++)
Console.WriteLine(args[i]);Console.WriteLine(args[i]);
}}

8. General Best Practices
public ArrayList GetList()public ArrayList GetList()
{{
ArrayList temp = new ArrayList();ArrayList temp = new ArrayList();
……
return temp;return temp;
}}
……
public void DoWpublic void DoWoork()rk()
{{
ArrayList list = new ArrayList();ArrayList list = new ArrayList();
list = GetList();list = GetList();
}}
 Avoid unnecessary object instantiation
public ArrayList GetList()public ArrayList GetList()
{{
ArrayList temp = new ArrayList();ArrayList temp = new ArrayList();
……
return temp;return temp;
}}
……
public void DoWork()public void DoWork()
{{
ArrayList list =ArrayList list = nullnull;;
list = GetList();list = GetList();
}}
public ArrayList GetList()public ArrayList GetList()
{{
ArrayList temp = new ArrayList();ArrayList temp = new ArrayList();
……
return temp;return temp;
}}
……
public void DoWork()public void DoWork()
{{
ArrayList list =ArrayList list = GetList()GetList();;
}}

9. General Best Practices
 Use StringBuilder for string manipulation
publicpublic stringstring ProcessLongText()ProcessLongText()
{{
string text = “How are you?”;string text = “How are you?”;
string s = text;string s = text;
for(int i = 0; i < 1000; i++)for(int i = 0; i < 1000; i++)
{{
s += text;s += text;
}}
return s;return s;
}}
public string ProcessLongText()public string ProcessLongText()
{{
string text = “How are you?”;string text = “How are you?”;
StringBuilder s = new StringBuilder(text);StringBuilder s = new StringBuilder(text);
for(int i = 0; i < 1000; i++)for(int i = 0; i < 1000; i++)
{{
s.Append(text);s.Append(text);
}}
return s.ToString();return s.ToString();
}}

10. General Best Practices
 Do not rely on exceptions in your code
try {try {
result = 100 / num;result = 100 / num;
}}
catch (Exception e) {catch (Exception e) {
result = 0;result = 0;
}}
if (num != 0)if (num != 0)
result = 100 / num;result = 100 / num;
elseelse
result = 0;result = 0;

11. General Best Practices
 Don’t reinvent the wheel, unless you are super
programmer, use existing class library
 Use Data Access Application Block for
accessing database
objectobject resultresult ==
SqlHelper.ExecuteScalar(connectionString,SqlHelper.ExecuteScalar(connectionString,
CommandType.StoredProcedure, spName, sqlParameters);CommandType.StoredProcedure, spName, sqlParameters);

12. ASP .NET Specific
 Disable ViewState if not used
 Use output cache to speed-up performance
 Disable SessionState if not used
 Avoid unnecessary round trips to the server
 Use Page.IsPostBack to avoid performing unnecessary
processing on a round trip
 Consider disabling AutoEventWireup for your application
<%@ OutputCache Duration=“60" VaryByParam="None" Shared="true" %><%@ OutputCache Duration=“60" VaryByParam="None" Shared="true" %>
<page enableSessionState="true|false|ReadOnly” /><page enableSessionState="true|false|ReadOnly” />

13. ASP .NET Specific
 Be sure to disable debug mode
 Avoid using DataBinder.Eval
<%# DataBinder.Eval(Container.DataItem, “myfield") %><%# DataBinder.Eval(Container.DataItem, “myfield") %>
<%#<%# ((DataRowView)Container.DataItem)[“myfield”].ToString()((DataRowView)Container.DataItem)[“myfield”].ToString() %>%>
<compilation defaultLanguage="c#"<compilation defaultLanguage="c#" debug=“debug=“falsefalse"" />/>

14. ASP .NET Specific
 Override method, instead of attaching delegate
to it
private void InitializeComponent()private void InitializeComponent()
{{
this.Load += new System.EventHandler(this.Page_Load);this.Load += new System.EventHandler(this.Page_Load);
}}
private void Page_Load(object sender, System.EventArgs e)private void Page_Load(object sender, System.EventArgs e)
{{
……
}}
protectedprotected overrideoverride voidvoid OnOnLoad(System.EventArgs e)Load(System.EventArgs e)
{{
……
}}

15. ASP .NET Specific
 Use IDataReader instead of DataSet
 Use Repeater instead of DataGrid (if possible)
 Use the HttpServerUtility.Transfer method to
redirect between pages in the same application
 Use early binding in Visual Basic .NET or
JScript code
<%@ Page Language="VB" Strict="true" %><%@ Page Language="VB" Strict="true" %>

16. Windows Forms Specific
 Use multithreading appropriately to make your
application more responsive
 Windows Forms uses the single-threaded apartment
(STA) model because Windows Forms is based on
native Win32 windows that are inherently apartment-
threaded. The STA model requires that any methods
on a control that need to be called from outside the
control's creation thread must be marshaled to
(executed on) the control's creation thread

17. Windows Forms Specific
if(this.InvokeRequired)if(this.InvokeRequired)
{{
this.Invoke(this.Invoke(
newnew EventHandler(this.DisableButton),EventHandler(this.DisableButton),
new object[] {new object[] { null, EventArgs.Emptynull, EventArgs.Empty }}
););
}}

18. Resources
http://www.asp.net/
http://www.gotdotnet.com/
http://www.microsoft.com/resources/practices/
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