C# tip How to String compare

Taswar Bhatti March 19, 2014 No Comments

Here is a quick C# tip, when using string compare don’t use

var str = "Hello";

if(str.ToLower() === "hello")

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var str = "Hello";

if(str.ToLower() === "hello")

use the Equals and StringComparison.InvariantCultureIgnoreCase enum.

var str = "Hello";

if(str.Equals("hello", StringComparison.InvariantCultureIgnoreCase))

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var str = "Hello";

if(str.Equals("hello", StringComparison.InvariantCultureIgnoreCase))

The thing you need to note is which rules are appropriate current culture, the invariant culture, ordinal or another culture entirely. One can create the compare from StringComparer.Create(culture, true)

.NET, C#

.net, C#, csharp, dotnet

C# tip use Dictionary TryGetValue

Taswar Bhatti February 10, 2014 No Comments

Here is another C# tip. Most of the time when you are trying to get a value from dictionary you would try to check if the key exist or not something like.

if(dictionary.ContainsKey(key))
{
  var value - dictionary[key];
 //do some stuff

}

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if(dictionary.ContainsKey(key))

{

var value - dictionary[key];

//do some stuff

}

But one can use TryGetValue

if(dictionary.TryGetValue(key, out value))
{
  //do stuff with value
}

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if(dictionary.TryGetValue(key, out value))

{

//do stuff with value

}

The benefit of using TryGetValue is that the dictionary is synchronized, there is no race condition.

.NET, C#

.net, C#, csharp, dotnet

WPF DataTemplate bind property to Parent ViewModel

Taswar Bhatti January 10, 2014 No Comments

Here is a hint when using WPF and you may come into a situation where you want to databind an element to its Parent ViewModel. As an example lets say you have a view that is binding to ViewModel and inside your xaml you have a control that has DataTemplate The code Below we are […]

.NET, C#, WPF

.net, C#, csharp, dotnet, WPF

C# tip: use params for method that takes variable number of arguments

Taswar Bhatti December 16, 2013 No Comments

In C# there is a params keyword which allows a method parameter to take variable number of arguments. MSDN Some notes on param It must always be the last parameter in the function/method definition There can only be one params keyword in a function/method parameter signature Example:

int Sum(int[] args)
{
  int sum = 0;
  foreach (var item in args)
  {
    sum += item;
  }

  return sum;
}

//calling the above Sum method we would call it like
int[] array = new int[] {1, 2, 3}
int result = Sum(array);

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int Sum(int[] args)

{

int sum = 0;

foreach (var item in args)

{

sum += item;

}

return sum;

}

//calling the above Sum method we would call it like

int[] array = new int[] {1, 2, 3}

int result = Sum(array);

But by changing it to params we […]

.NET, C#

.net, C#, csharp, dotnet

C# tip: out parameter keyword

Taswar Bhatti December 11, 2013 No Comments

In C# there is the out parameter keyword which causes arguments to be passed by reference. It is like the ref keyword, except that ref requires that the variable be initialized before it is passed. Example:

void Init(out int x)
{
 x = 47;
}

int x;

Init(out x);

Console.WriteLine(x); //x now is 47

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void Init(out int x)

{

x = 47;

}

int x;

Init(out x);

Console.WriteLine(x); //x now is 47

The out parameter keyword provides a way for a method to output multiple values from a method without […]

.NET, C#

.net, C#, csharp, dotnet

C# the use of ref keyword

Taswar Bhatti December 6, 2013 No Comments

In C# when using the ref keyword it causes an argument to be passed by reference, not by value. In order to use a ref as a parameter, both the method definition and the calling method must explicitly use the ref keyword, and also the variable must be initialized before passing in. In the example […]

.NET, C#

.net, C#, csharp, dotnet

C# tip: Use Path Combine for file or directory path information

Taswar Bhatti December 4, 2013 1 Comment

.NET provides in its System.IO namespace the Path class which performs operations on String instances that contain file or directory path information. These operations are performed in a cross-platform manner. Most of the time we see develeopers writing code like

string path = somePath + "\\" + filename;

1	string path = somePath + "\\" + filename;

But by using Path.Combine we can provide a cross platform path

string somePath = @"C:\temp";
string filename = "dat.txt";
string path = Path.Combine(somePath,filename);

//produce an output of C:\temp\dat.txt
//linux: C:/temp/dat.txt

string[] paths = {@"c:\My Music", "2013", "media", "banner"};
string fullPath = Path.Combine(paths);
//output c:\My Music\2013\media\banner

string path1 = @"C:\Temp";
string path2 = "My Music";
fullPath = Path.Combine(path1, path2);

//output: C:\Temp\My Music

fullPath = Path.Combine(string.Empty, path2);
//output: My Music
	
fullPath = Path.Combine(path1, string.Empty);
//output: C:\Temp

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string somePath = @"C:\temp";

string filename = "dat.txt";

string path = Path.Combine(somePath,filename);

//produce an output of C:\temp\dat.txt

//linux: C:/temp/dat.txt

string[] paths = {@"c:\My Music", "2013", "media", "banner"};

string fullPath = Path.Combine(paths);

//output c:\My Music\2013\media\banner

string path1 = @"C:\Temp";

string path2 = "My Music";

fullPath = Path.Combine(path1, path2);

//output: C:\Temp\My Music

fullPath = Path.Combine(string.Empty, path2);

//output: My Music

fullPath = Path.Combine(path1, string.Empty);

//output: C:\Temp

By using […]

.NET, C#

.net, C#, csharp, dotnet

Documentation comment your C# code use GhostDoc at least

Taswar Bhatti December 2, 2013 No Comments

Recently have been going through some old code to review the comments in them from other developers and what I find out is developers tend to have really bad comments & documentation in their code Example:

public class Person 
{
   /// &lt;summary>
   /// Constructor
   /// &lt;/summary>
   public Person() {}
   
}

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public class Person

{

/// <summary>

/// Constructor

/// </summary>

public Person() {}

}

From the above code it is obvious that it is the constructor but does the comment tell me […]

.NET, C#, Misc

.net, C#, csharp, dotnet

LINQ tip – Ordering collection using existing array/collection using OrderBy

Taswar Bhatti November 29, 2013 5 Comments

Here is a LINQ tip where you may wish to order a collection with an existing ordering of another collection. Example:

int[] displaySeq = new int[] { 1, 8, 5, 7, 13 }; //the ordering we want at the end

//collection that we will be sorting on
List<Person> people = new List<Person>();
people.Add(new Person { DisplaySeq = 5});
people.Add(new Person { DisplaySeq = 13});
people.Add(new Person { DisplaySeq = 7});
people.Add(new Person { DisplaySeq = 1});
people.Add(new Person { DisplaySeq = 8});

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int[] displaySeq = new int[] { 1, 8, 5, 7, 13 }; //the ordering we want at the end

//collection that we will be sorting on

List<Person> people = new List<Person>();

people.Add(new Person { DisplaySeq = 5});

people.Add(new Person { DisplaySeq = 13});

people.Add(new Person { DisplaySeq = 7});

people.Add(new Person { DisplaySeq = 1});

people.Add(new Person { DisplaySeq = 8});

Currently as it stands our data is stored in the order of { 5, 13, 7, 1, 8 } and we wish to order them in terms of { 1, 8, 5, 7, […]

.NET, C#

.net, C#, csharp, dotnet, LINQ

C# tip – Marking method or class as Obsolete/Deprecated

Taswar Bhatti November 25, 2013 No Comments

Obsolete or Deprecated? How do you mark a class or method as deprecated/obsolete? By using the Obsolete attribute

[Obsolete]
public class Person { }

[Obsolete("Class is obsolete, use PersonImpl")]
public class Person { }

//compilation to fail methods calling this code
[Obsolete("Class is obsolete, use PersonImpl", true)]
public class Person { }

[Obsolete("Method is obsolete, use SomeMethod2", true)]
public void SomeMethod() { }

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[Obsolete]

public class Person { }

[Obsolete("Class is obsolete, use PersonImpl")]

public class Person { }

//compilation to fail methods calling this code

[Obsolete("Class is obsolete, use PersonImpl", true)]

public class Person { }

[Obsolete("Method is obsolete, use SomeMethod2", true)]

public void SomeMethod() { }

.NET, C#

.net, C#, csharp, dotnet

C# tip How to String compare

C# tip use Dictionary TryGetValue

WPF DataTemplate bind property to Parent ViewModel

C# tip: use params for method that takes variable number of arguments

C# tip: out parameter keyword

C# the use of ref keyword

C# tip: Use Path Combine for file or directory path information

Documentation comment your C# code use GhostDoc at least

LINQ tip – Ordering collection using existing array/collection using OrderBy

C# tip – Marking method or class as Obsolete/Deprecated

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