Tag: C#

I have a task to need to get a DataTable, however, all existing objects are List, I need convert some of those lists to DataTables. Before I wrote my own code to do it. I searched internet and got 2 perfect articles which I need.

1: From DotNet Friends, By patriwala, Convert Generic List In To DataTable
  
   A simple and easy to use one, I adopted this solution.

2: Casting from a Collection to a Data Table using Generics and Attributes by Joseph Finsterwald

Here I copy some code from patriwala’s article:

/// <typeparam name=”T”>Custome Class </typeparam>
/// <param name=”lst”>List Of The Custome Class</param>
/// <returns> Return the class datatbl </returns>
public static DataTable ConvertTo<T>(IList<T> lst)
{
//create DataTable Structure
DataTable tbl = CreateTable<T>();
Type entType = typeof(T);

PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(entType);
//get the list item and add into the list
foreach (T item in lst)
{
DataRow row = tbl.NewRow();
foreach (PropertyDescriptor prop in properties)
{
row[prop.Name] = prop.GetValue(item);
}
tbl.Rows.Add(row);
}

return tbl;
}

/// <summary>
///
/// </summary>
/// <typeparam name=”T”>Custome Class</typeparam>
/// <returns></returns>
public static DataTable CreateTable<T>()
{
//T –> ClassName
Type entType = typeof(T);
//set the datatable name as class name
DataTable tbl = new DataTable(entType.Name);
//get the property list
PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(entType);
foreach (PropertyDescriptor prop in properties)
{
//add property as column
tbl.Columns.Add(prop.Name, prop.PropertyType);
}
return tbl;
}

And, how to use? Very easy, I show you my own sample:

List<SoldTerritories> listSoldTerritories = GetSoldTerritoriesList();
DataTable dt = ConvertTo<SoldTerritories>(listSoldTerritories);

That is!

I got part of content from vcskicks.com

 
7 Ways To Optimize C# Code

1. Use StringBuilder or String ?

  StringBuilder is faster mostly with big strings. This means if you have a loop that will add to a single string for many iterations then a StringBuilder class is definitely much faster than a string type.

However if you just want to append something to a string a single time then a StringBuilder class is overkill. A simple string type variable in this case improves on resources use and readability of the C# source code.
 
2. Comparing Non-Case-Sensitive Strings

if(str1.ToLower() == str2.ToLower()) …

But better use this way:

To check if two strings are equal ignoring case would look like this:

string.Compare(str1, str2, true) == 0 //Ignoring cases

The C# string.Compare function returns an integer that is equal to 0 when the two strings are equal.

3. Use string.Empty

Try to replace lines like:

if (str == “”)

with:

if (str == string.Empty)

This is simply better programming practice and has no negative impact on performance.

Note, there is a popular practice that checking a string’s length to be 0 is faster than comparing it to an empty string. While that might have been true once it is no longer a significant performance improvement. Instead stick with string.Empty.

4. Replace ArrayList with List<>

5. Use && and || operators

if (object1 != null && object1.runMethod())

If object1 is null, with the && operator, object1.runMethod()will not execute. If the && operator is replaced with &, object1.runMethod() will run even if object1 is already known to be null, causing an exception.

6. Smart Try-Catch

Using a try statement to keep code “simple” instead of using if statements to avoid error-prone calls makes code incredibly slower. Restructure your source code to require less try statements.

7. Replace Divisions

C# is relatively slow when it comes to division operations. One alternative is to replace divisions with a multiplication-shift operation to further optimize C#. The article explains in detail how to make the conversion.
Conclusion

If you wanna write code to jump to specified tab page of a tab control, you can not use Focus() method. or BringToFront(), Show() etc.

The right way is :

this.tabControl1.SelectedTab = this.tabPage3 ;