Problem with getting listview item

Tanx Christian for your reply.let me post some parts of my code:

//here is the part when i fill up my listview:
DataSet da = new DataSet();
connRead.Fill(da);
listView.DataContext = da.Tables[0];

//this part is for when i want to get my items value:
ListViewItem container = null;
for (int i = 0; i < listView.Items.Count;i++ )
{

container = listView.ItemContainerGenerator.ContainerFromIndex(i) as ListViewItem;

if (container != null)//here for i = 3 and onward i get null value
{
...
}


this is my xaml part:

<ListView x:Name="listView" Height="202" ItemsSource="{Binding}"  SelectionChanged="listView_SelectionChanged"  HorizontalAlignment="Left" Margin="20,84,0,0" VerticalAlignment="Top" Width="435" IsSynchronizedWithCurrentItem="{x:Null}" DataContext="{Binding}">
               <ListView.ItemTemplate>
               <DataTemplate>
                <Grid x:Name="grid">
               <Grid.RowDefinitions>
                   <RowDefinition Height="Auto"/>
                   <RowDefinition Height="Auto"/>
                   <RowDefinition Height="50"/>
                   <RowDefinition Height="Auto"/>
                   <RowDefinition Height="Auto"/>
               </Grid.RowDefinitions>
               <Grid.ColumnDefinitions>
                   <ColumnDefinition/>
                   <ColumnDefinition/>
                   <ColumnDefinition/>
                   <ColumnDefinition/>
               </Grid.ColumnDefinitions>
                     <Image x:Name="image1" Width="70" Height="110" Grid.Row="1" Grid.Column="1"  Source="{Binding PhotoName}"></Image>
                     <Label x:Name="email" Grid.Row="0" Grid.Column="2"  Content="{Binding Email}"></Label>
                     <Label x:Name="name" Grid.Row="1" Grid.Column="2" Content="{Binding Name}"></Label>
                     <CheckBox x:Name="chB" Grid.Row="0" Grid.Column="0" ></CheckBox>
                </Grid>
               </DataTemplate>
           </ListView.ItemTemplate>
       </ListView>