Remove Duplicates from Rows/List/Column Values

Introduction

This article will show code to avoid duplicates from a Generic List.

Background

This is used to remove the dupliates rows from list items:

Method 1:

This will return distinct column values based on your datatable columns. Which is used to filter.

Also this will used to "Select" particular column in a datatable to display in grdiview with AutoGeneratedColumn="True" Mode

Using Code:

DataTable tableWithOnlySelectedColumns = new DataView(DataTableName).ToTable(distinct, ColumnNames);

example 1:

public void BindGridView(){

string str[] = {"Dept","EmpFName","EmpLName","Salary","City"};

GridView1.DataSource = GetSelectedColumns(dv.ToTable(), str, true);

GridView1.DataBind();

}

public DataTable GetSelectedColumns(DataTable dtTemp, string[] ColumnNames, bool distinct)
{
DataTable tableWithOnlySelectedColumns = new DataView(dtTemp).ToTable(distinct, ColumnNames);
return tableWithOnlySelectedColumns;
}

Method 2:

List<int> ProductCode = new List<int> { 21, 46, 46, 55, 17, 21, 55, 55 };

IEnumerable<int> ProductCode = ProductCode.Distinct();

Method 3 : Using Lamda Expression

List <ListName> listObject =  listname.GroupBy(x=> x.ColumnName).Select(y=> y.First()).TOList();

List<ClsPubRepayDetails> repayDetails1 = ((List<ClsPubRepayDetails>)DeSeriliaze (byteLobs));
List<ClsPubRepayDetails> repayDetails = repayDetails1.GroupBy(x => x.InstallmentNo).Select(y => y.First()).ToList();