SQLite C# Example

C# > SQLite

SQLiteConnection.CreateFile("MyDatabase.sqlite");

SQLiteConnection  m_dbConnection = new SQLiteConnection("Data Source=MyDatabase.sqlite;Version=3;");

m_dbConnection.Open();

string sql = "create table project (name varchar(100), id int)";

SQLiteCommand command = new SQLiteCommand(sql, m_dbConnection);

command.ExecuteNonQuery();

sql = "insert into project (name, id) values ('project 1', 1)";

command = new SQLiteCommand(sql, m_dbConnection);

command.ExecuteNonQuery();

sql = "select * from project order by id desc";

command = new SQLiteCommand(sql, m_dbConnection);

SQLiteDataReader reader = command.ExecuteReader();

while (reader.Read())

 Console.WriteLine("Name: " + reader["name"] + "\tScore: " + reader["id"]);

PlantUML Set ForeColor and BackColor

PlantUML > Set ForeColor and BackColor

Font Color in Participants 

This example will set font color to white and background color to some custom color.

participant "<color:#white>Setup" as Setup #FD9A00

C# get property value from object using reflection

C# > Reflection > Property Info > GetValue

Returns the property value of a specified object.

Example

Get property value from object using reflection.

private static object GetPropValue(object src, string propName)

{

   return src.GetType().GetProperty(propName).GetValue(src, null);

}

Validate Data Models Using DataAnnotations Attributes C#

C# > System > ComponentModel > DataAnnotations

Provides attribute classes that are used to define metadata.

Example

Validate property class with range numbers

using System;

using System.ComponentModel.DataAnnotations;

using System.Windows.Forms;

namespace WindowsFormsApplication8

{

    public class Person

    {

        private int id;

        [Display(Name = "Person Id")]

        [Range(0, 1000)]

        public int Id

        {

            get { return id; }

            set

            {

                Validator.ValidateProperty(value,

                    new ValidationContext(this, null, null) { MemberName = "Id" });

                id = value;

            }

        }

    }

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            Person p = new Person();

            p.Id = 1;

            p.Id = 1001;

        }

    }

}

Rename files from a folder C#

C# > Files > File Class > Move

Moves a specified file to a new location.

• option to specify a new file name

Example 

Rename files from a folder 

DirectoryInfo d = new DirectoryInfo(@"D:\folder");

FileInfo[] infos = d.GetFiles("*.*");

int i = 1;

foreach (FileInfo f in infos)

{

  File.Move(f.FullName, Path.Combine(f.DirectoryName, + i.ToString() + ".jpg"));

  i++;

}

Mock Assembly Unit Test C#

C# > Unit tests > Mock Assembly 

If you try to mock

var mock = new Mock<Assembly>();

You will get this error:

The type System.Reflection.Assembly implements ISerializable, but failed to provide a deserialization constructor

Solution

Mock _Assembly interface instead of Assembly class.

var mock = new Mock<_Assembly>();

mock.Setup(w => w.GetTypes()).Throws(new Exception());

yield C# Example with KeyValuePair

C# > Keywords > yield

Yield  returns each element one at a time.

When to use:

• when calculate the next item in the list 
• for infinite sets

Example

IEnumerable<KeyValuePair<string, string>> dataList = GetData();

dataList.ToList().ForEach(s => MessageBox.Show(s.Key + s.Value));

private IEnumerable<KeyValuePair<string, string>> GetData()

{

yield return new KeyValuePair<string, string>("1", "A");

yield return new KeyValuePair<string, string>("2", "B");

yield return new KeyValuePair<string, string>("3", "C");

}