Using Datasets and Data Adapters - Beginning C# 2008 Databases: From Novice to Professional - page 283

How It Works

This program is basically the same as the other examples, so we'll focus on its use of a
data view. You create a new data view and initialize it by passing four parameters to its
constructor.

// create data view
DataView dv = new DataView(
dt,
"country = 'Germany'",
"country",
DataViewRowState.CurrentRows

);

The first parameter is a data table, the second is a filter for the contents of the data
table, the third is the sort column, and the fourth specifies the types of rows to include
in the data view.
System.Data.DataViewRowState is an enumeration of states that rows can have in a
data view's underlying data table. Table 13-1 summarizes the states.

Table 13-1. Data View Row States

DataViewRowState Members

Description

Added

A new row

CurrentRows

Current rows including unchanged, new, and modified ones

Deleted A deleted row

ModifiedCurrent The current version of a modified row

ModifiedOriginal The original version of a modified row

None

None of the rows

OriginalRows

Original rows, including unchanged and deleted rows

Unchanged A row that hasn't been modified

Every time a row is added, modified, or deleted, its row state changes to the appro-
priate one in Table 13-1. This is useful if you're interested in retrieving, sorting, or filtering
specific rows based on their state (for example, all new rows in the data table or all rows
that have been modified).
You then loop through the rows in the data view.