Bind generic dictionary collection to combobox

Dictionary<string, string>  DicSearch;
DicSearch = new Dictionary<string, string>();
DicSearch.Add("1", "Mohit");
DicSearch.Add("2", "Agrawal");

cboSearch.DataSource  = new BindingSource(DicSearch, null);
cboSearch.DisplayMember = "value";
cboSearch.ValueMember = "key";
DicSearch = null;

Regular Expression

Regular Express class and validation done himself.

SqlCommand Query based on parameters

SqlCommand command = new SqlCommand();
command.CommandText = "SELECT * FROM Emplyoee emp WHERE  emp.Name=@EmpName";
command.Parameters.Add(new SqlParameter(" @EmpName", 50));

// Execute the SQL Server command...
SqlDataReader reader = command.ExecuteReader();
DataTable tblemplyee = new DataTable();
tblemplyee.Load(reader);

foreach (DataRow rowProduct in  tblemplyee.Rows)
{
    // Use the data...
}


NOTE: This is a good way to block SQL injection

"" vs String.Empty

String.Empty is faster than "" because it doesn't create a new string object instance. Creating new instances brings penalties on both execution speed and memory usage.

Example:

// Slowest

str1 == "";

// Slow

str1.Equals(" ") == false

//Fast

str1 == String.Empty

// Fastest

str1.Equals(String.Empty) == false