How to remove duplicate row from a DataTable

Today in my development procedure I want to remove duplicate rows from DataTable. There is a lot of solution in community. But I think that I need to make the solution for flexibility of use.
Now I want to shared this with you. Hope that it will helpful for others developers.

First Solution:

public DataTable RemoveDuplicateRows(DataTable dTable, string colName)
{
Hashtable hTable = new Hashtable();
ArrayList duplicateList = new ArrayList();

//Add list of all the unique item value to hashtable, which stores combination of key, value pair.
//And add duplicate item value in arraylist.
foreach (DataRow drow in dTable.Rows)
{
if (hTable.Contains(colName==""?drow[0]:drow[colName]))
duplicateList.Add(drow);
else
hTable.Add(colName==""?drow[0]:drow[colName], string.Empty);
}

//Removing a list of duplicate items from datatable.
foreach (DataRow dRow in duplicateList)
dTable.Rows.Remove(dRow);

//Datatable which contains unique records will be return as output.
return dTable;
}

we can call this method

RemoveDuplicateRows(dataTable,""); or
RemoveDuplicateRows(dataTable,"word");

Second Solution:

private void btnRemove_Click(object sender, EventArgs e)
{
List keyColumns = new List();
keyColumns.Add("ColumnName1");
keyColumns.Add("ColumnName2");
keyColumns.Add("ColumnName3");
RemoveDuplicates(ref dtAlarmData, keyColumns);
}

//Method to remove Duplicate value from DataTable

public static void RemoveDuplicatesFromDataTable(ref DataTable table, List keyColumns)
{
Dictionary uniquenessDict = new Dictionary(table.Rows.Count);
StringBuilder stringBuilder = null;
int rowIndex = 0;
DataRow row;
DataRowCollection rows = table.Rows;
while (rowIndex < rows.Count - 1) { row = rows[rowIndex]; stringBuilder = new StringBuilder(); foreach (string colname in keyColumns) { //If no column name found it will check the first column by default. stringBuilder.Append(colname==""?((string)row[0]):((string)row[colname]));
}

if (uniquenessDict.ContainsKey(stringBuilder.ToString()))
{
rows.Remove(row);
}
else
{
uniquenessDict.Add(stringBuilder.ToString(), string.Empty);
rowIndex++;
}
}
}