title: when i am pressing hardware back button picker is getting called from that page
body: <p><a href="https://i.stack.imgur.com/hyM5G.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hyM5G.png" alt="enter image description here"></a>I have picker on page when I am calling picker and value selected and pressing hardware back button that picker is getting called again. I tried disabling back button but its picker is getting called.</p>
  
  <pre><code>protected override bool OnBackButtonPressed()
  {          
      base.OnBackButtonPressed();
      return true;
  }
  </code></pre>
  
  <p>but after this also when pressing back button picker is getting called again and again</p>
  
  <p>check this xaml file below from that UserListPicker is getting 
     called when pressing back button.</p>
  
  <pre><code> &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
           xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
           xmlns:material="clr- 
    namespace:XF.Material.Forms.UI;assembly=XF.Material.Forms" 
           x:Class="Test.Views.CommentsPage"
           Icon="ic_message.png"
           BackgroundColor="White"
           Title="Simon"&gt;
  &lt;NavigationPage.TitleView&gt;
      &lt;StackLayout
          Padding="0,0,0,0"
          HeightRequest="35"
          HorizontalOptions="FillAndExpand"
          Orientation="Horizontal"
          VerticalOptions="Center"&gt;
          &lt;ImageButton
              Aspect="AspectFit"
              HorizontalOptions="StartAndExpand"
              Source="ic_check.png"
              BackgroundColor="Transparent"
              Clicked="btnSendClicked"&gt;
         &lt;/ImageButton&gt;
          &lt;Label Text="Send Comments" TextColor="White" 
           HorizontalOptions="StartAndExpand" FontSize="Large"  /&gt;
          &lt;ImageButton
              Aspect="AspectFit"
              HorizontalOptions="EndAndExpand"
              Source="ic_close.png"
              BackgroundColor="Transparent"
              Clicked="btnCloseClicked"
              Padding="0,0,10,0"
              CommandParameter="{Binding .}"&gt;
          &lt;/ImageButton&gt;
      &lt;/StackLayout&gt;
    &lt;/NavigationPage.TitleView&gt;
    &lt;ContentPage.Content&gt;
    &lt;StackLayout&gt;
     &lt;StackLayout HeightRequest="60" BackgroundColor="#002343" &gt;
      &lt;Label x:Name="lblPartyName"  HorizontalTextAlignment="Center" 
       TextColor="White" HorizontalOptions="FillAndExpand" 
        VerticalOptions="CenterAndExpand" FontSize="Large"&gt;&lt;/Label&gt;
          &lt;/StackLayout&gt;
  
          &lt;StackLayout Orientation="Horizontal" Margin="10,5,10,5"&gt;
              &lt;Grid HorizontalOptions="FillAndExpand"  RowSpacing="0"&gt;  
        &lt;Grid.RowDefinitions&gt;  
        &lt;RowDefinition Height="*"/&gt;
        &lt;/Grid.RowDefinitions&gt;  
       &lt;material:MaterialCard BackgroundColor="#F0F0F0" 
                              Padding="5" OutlineColor="Navy"  
                              HasShadow="true" 
                              BorderColor="Navy"  
                              Margin="5" HeightRequest="45"&gt;
       &lt;AbsoluteLayout&gt;
       &lt;StackLayout AbsoluteLayout.LayoutBounds="0,1,1,1" AbsoluteLayout.LayoutFlags="All" BackgroundColor="#F0F0F0" &gt;
              &lt;StackLayout Orientation="Horizontal"&gt;
              &lt;Label Grid.Row="0" 
                     x:Name="partyNameLbl"  
                     TextColor="Orange"  
                     FontSize="Medium" 
                     FontAttributes="Bold"  /&gt;
              &lt;Label Grid.Row="0" Grid.Column="1" 
                     x:Name="amountLbl" 
                     Text="{Binding StringFormat='{0:C0}'}"
                     TextColor="Orange"  
                     FontSize="Medium" 
                     FontAttributes="Bold" 
                     HorizontalOptions="EndAndExpand" /&gt;
              &lt;/StackLayout&gt;
             &lt;/StackLayout&gt;
       &lt;/AbsoluteLayout&gt;
      &lt;/material:MaterialCard&gt;
          &lt;/Grid&gt;
          &lt;/StackLayout&gt;
          &lt;StackLayout HeightRequest="30" Margin="10,0,10,0" Orientation="Horizontal"&gt;
              &lt;Label  Text="Assigned To:" HeightRequest="25" FontSize="Medium" TextColor="Black" /&gt;
              &lt;Label  x:Name="assignedUserNameLbl" HeightRequest="25" FontSize="Medium"  TextColor="Orange"  /&gt;
          &lt;/StackLayout&gt;
  &lt;ScrollView &gt;
          &lt;Grid Padding="5" Margin="10,5,10,5"&gt;
              &lt;Grid.RowDefinitions&gt;
               &lt;RowDefinition Height="30"/&gt;  
               &lt;RowDefinition Height="Auto"/&gt;
               &lt;RowDefinition Height="30"/&gt;  
               &lt;RowDefinition Height="Auto"/&gt;
               &lt;RowDefinition Height="30"/&gt;  
               &lt;RowDefinition Height="Auto"/&gt;
                  &lt;/Grid.RowDefinitions&gt;
               &lt;!--mitigating Factor--&gt;
                  &lt;StackLayout Orientation="Horizontal" Grid.Row="0"&gt;      
              &lt;Label Text="Mitigating Factor" 
                     TextColor="Black"  
                     HorizontalOptions="StartAndExpand" 
                     FontSize="Large" /&gt;
              &lt;ImageButton Grid.Column="1" 
                           Source="ic_pencil.png"
                           BackgroundColor="White"  
                           HorizontalOptions="EndAndExpand" 
                           VerticalOptions="StartAndExpand"  
                           Aspect="AspectFit" 
                           HeightRequest="25" 
                           Clicked="onMitigatingEditBtnClicked"   /&gt;
             &lt;/StackLayout&gt;
              &lt;StackLayout Orientation="Horizontal" Grid.Row="1"&gt;
              &lt;Image Source="ic_comments.png" 
                     HorizontalOptions="Start"
                     Aspect="AspectFit" 
                     VerticalOptions="StartAndExpand"  /&gt;
              &lt;Editor Grid.Column="1" 
                      x:Name="entryMitigatingFactor"  
                      TextColor="Gray"  
                      VerticalOptions="StartAndExpand" 
                      HorizontalOptions="FillAndExpand" 
                      HeightRequest="100" 
                      IsReadOnly="true" /&gt;
             &lt;/StackLayout&gt;
                  &lt;!--Approval Conditions--&gt;
               &lt;StackLayout Orientation="Horizontal" Grid.Row="2"&gt;      
              &lt;Label Text="Approval Conditions" 
                     TextColor="Black"  
                     HorizontalOptions="StartAndExpand" 
                     FontSize="Large" 
                     /&gt;
              &lt;ImageButton Grid.Column="1" 
                           Source="ic_pencil.png" 
                           BackgroundColor="White" 
                           HorizontalOptions="EndAndExpand"
                           VerticalOptions="StartAndExpand"  
                           Aspect="AspectFit" HeightRequest="25" 
                           Clicked="onApprovalEditBtnClicked"   /&gt;
             &lt;/StackLayout&gt;
  
              &lt;StackLayout Orientation="Horizontal" Grid.Row="3"&gt;
              &lt;Image Source="ic_comments.png"  
                     HorizontalOptions="Start"
                     Aspect="AspectFit" 
                     VerticalOptions="StartAndExpand"  /&gt;
              &lt;Editor Grid.Column="1" 
                      x:Name="entryApproval"  
                      TextColor="Gray" 
                      VerticalOptions="StartAndExpand"
                      HorizontalOptions="FillAndExpand"
                      HeightRequest="100" 
                      IsReadOnly="true" /&gt;
             &lt;/StackLayout&gt;
                   &lt;!--Comments--&gt;
              &lt;StackLayout Orientation="Horizontal" Grid.Row="4"&gt;
              &lt;Label Text="Comments"  
                     TextColor="Black" 
                     HorizontalOptions="StartAndExpand" 
                     FontSize="Large" 
                     VerticalOptions="StartAndExpand" /&gt;
              &lt;ImageButton Grid.Column="1"  
                           Source="ic_pencil.png"
                           BackgroundColor="White"
                           HeightRequest="25" 
                           HorizontalOptions="EndAndExpand"
                           Aspect="AspectFit" 
                           VerticalOptions="StartAndExpand"
                           Clicked="onCommentEditClicked"  /&gt;
              &lt;/StackLayout&gt;
              &lt;StackLayout Orientation="Horizontal" Grid.Row="5"&gt;
              &lt;Image Source="ic_comments.png"  
                     HorizontalOptions="Start" 
                     Aspect="AspectFit"  
                     VerticalOptions="StartAndExpand"  /&gt;
              &lt;Editor Grid.Column="1" 
                      TextColor="Gray"
                      HorizontalOptions="FillAndExpand" 
                      VerticalOptions="StartAndExpand" 
                      x:Name="entryCommentTxt" 
                      HeightRequest="100"
                      IsReadOnly="true"/&gt;
          &lt;/StackLayout&gt;   
          &lt;/Grid&gt;
              &lt;/ScrollView&gt;
          &lt;StackLayout Orientation="Horizontal" Margin="10,0,10,0"  x:Name="pickerStack"&gt;
          &lt;Picker x:Name="userListPicker" 
                  HorizontalOptions="FillAndExpand" 
                  ItemsSource="{Binding PendingList}"
                  SelectedIndexChanged="OnPickerSelectedIndexChanged"  
                  SelectedIndex="{Binding id}" 
                  ItemDisplayBinding="{Binding shortMobileName}"  
                  BackgroundColor="White"  
                  Title="Select Action"
                  TitleColor="{StaticResource backTitleColor}" &gt;
  
             &lt;/Picker&gt; 
               &lt;Picker x:Name="processStageUserPicker" 
                       IsVisible="false" HorizontalOptions="FillAndExpand" 
                       ItemsSource="{Binding ProcessUserList}" 
                       SelectedIndex="{Binding id}" 
                       ItemDisplayBinding="{Binding userName }"  
                       BackgroundColor="White"
                       Title="Select Action"
                       TitleColor="{StaticResource backTitleColor}" &gt;
  
             &lt;/Picker&gt; 
              &lt;/StackLayout&gt;
          &lt;StackLayout Orientation="Horizontal" VerticalOptions="EndAndExpand" &gt;
              &lt;material:MaterialButton Text="CANCEL" 
                                       AllCaps="false"  
                                       TextColor="Black" 
                                       BackgroundColor="#F0F0F0" 
                                       VerticalOptions="StartAndExpand" 
                                       HorizontalOptions="FillAndExpand" 
                                       ButtonType="Flat" 
                                       PressedBackgroundColor="{StaticResource btnPressedColor}" 
                                       FontAttributes="Bold" 
                                       Clicked="onCancelBtnClicked"/&gt;
              &lt;material:MaterialButton Text="SAVE"  
                                       AllCaps="false" 
                                       TextColor="Black"
                                       BackgroundColor="#F0F0F0" 
                                       VerticalOptions="EndAndExpand"  
                                       HorizontalOptions="FillAndExpand"
                                       ButtonType="Flat"
                                       FontAttributes="Bold" 
                                       PressedBackgroundColor="{StaticResource btnPressedColor}" 
                                       Clicked="onApproveBtnClicked"/&gt;
          &lt;/StackLayout&gt;
          &lt;StackLayout Orientation="Horizontal" BackgroundColor="{StaticResource backTitleColor}" HorizontalOptions="FillAndExpand"&gt;
              &lt;material:MaterialButton PressedBackgroundColor="{StaticResource btnPressedColor}" 
                                       AllCaps="false"
                                       Text="Message" 
                                       TextColor="White" 
                                       BackgroundColor="{StaticResource backTitleColor}" 
                                       ButtonType="Flat"
                                       FontSize="Medium"
                                       BorderWidth="0" 
                                       VerticalOptions="StartAndExpand" 
                                       HorizontalOptions="StartAndExpand"  /&gt;
          &lt;/StackLayout&gt;
    &lt;/StackLayout&gt;
  &lt;/ContentPage.Content&gt;
  </code></pre>
  
  <p></p>