Scrollviewer & SIP Issue (WP7.5 Mango) - windows-phone-7

I am working on an application which includes a registration form. The form contains multiple text entry boxes, and so a ScrollViewer is used to allow them all to be displayed on one page.
The following is a stripped down example of the XAML code I am using:
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
<TextBlock x:Name="ApplicationTitle" Text="SCROLLVIEWER TEST" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock x:Name="PageTitle" Text="registration" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
</StackPanel>
<ScrollViewer Grid.Row="1">
<StackPanel>
<TextBlock Text="Hello" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello1" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello2" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello3" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello4" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello5" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello6" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello7" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="Hello8" Margin="12,0,0,0"/>
<TextBox />
<TextBlock Text="END" Margin="12,0,0,0"/>
<TextBox />
</StackPanel>
</ScrollViewer>
</Grid>
(Note that the ScrollViewer is inside a grid cell, which means that the title panel should stay OnScreen at all times)
The scrolling works perfectly fine, so that is not an issue. However, when the user selects a TextBox to enter data (i.e. the soft keyboard opens), the system pushes the content of the entire page around (including the registration title panel), which is not expected behaviour.
[See the People app on Windows Phone and try adding a new contact. This contains a similar structure, but the ScrollViewer behaves correctly by only pushing content in the scrollviewer up]
Test Cases
Select a TextBox that is visible near the top of the screen, to open the keyboard.
Attempt to scroll to the bottom of the page with keyboard open.
Items at the bottom of the page are unreachable.
or
Select a TextBox that is visible near the bottom of the screen.
Content of entire page is pushed up.
Attempt to scroll to the top of the page with keyboard open.
Items at the top of the page are unreachable, and title panel never comes back into view until keyboard is closed.
Any help on resolving this issue would be appreciated. Thanks.

The problem is that the ScrollViwer height is not modified after the keyboard appears so it becomes clipped. One solution would be to modify the height of the scrollviwer (according to the keyboard height) and then reposition it (this might give you some headaches).
Another problem is knowing when the keyboard appears - you could register for the GotFocus/LostFocus events on all your TextBoxes but it's not a great solution. This might help you: http://blogs.msdn.com/b/jaimer/archive/2010/11/05/guessing-if-the-sip-is-visible-in-a-windows-phone-application.aspx
Hope this helps a little :)

I think you can solve this by coming at the problem from another angle. The phone will scroll up the page so that the SIP (software keyboard) never covers up the TextBox which has focus.
However you can force the SIP to hide by detecting touch events on the top element contained in your ScrollViewer, e.g.:
<ScrollViewer Grid.Row="1">
<StackPanel ManipulationDelta="OnScrollViewerGridManipulationDelta">`
Then, by giving the focus to a hidden button (0x0 pixels in size) this will force the SIP to close. Then it will be possible for your users to scroll up and down the scrollviewer as expected...
private void OnScrollViewerGridManipulationDelta(object sender, System.Windows.Input.ManipulationDeltaEventArgs e)
{
// This will hide the SIP if it is currently showing.
// We can't do this directly, but we can force this by taking focus away from any of the TextBoxes that may have it.
this.hiddenButton.Focus();
}

I've had the same issue with an app I've developed and the way I dealt with it was to find out the auto height of the panel containing the input textboxs and then manually set the height and add approximately 400 - 500 px to the bottom to make it scroll nicely. The effect is quite smooth and will not make your UI look "hackish" IMHO.
In your case you will have to find out the automatic height of the LayoutRoot Grid and then on RowDefinitionof Row 1 set the height manually - remembering to add an extra 400px (or whatever looks appropriate in your situation).
For ease of input I then handled each OnKeyDown event of each TextBox to change the focus to the next TextBox upon hitting Enter. On the last TextBox I set the focus to this.focus() which sets focus to the Page and hides the SIP.

Have a look at my small library please - https://siphelper.codeplex.com/
It modifies height of scrollviewer and content can be scrolled to the topmost/bottommost point.
If you have any suggestions - feel free to contact me.

Related

LongListSelector performance is very bad when enclosed in ScrollViewer

I have a UserControl that needs to contain a bunch of controls on top and a LongListSelector below them. Total height of the whole UserControl may (and almost always will) exceed the screen height and in that case a whole UserControl must be scrollable.
My current setup is as follows:
<staff:UserContentControl
xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:controls="clr-namespace:MyApp.Controls"
xmlns:staff="clr-namespace:MyApp.Helpers"
x:Class="MyApp.Controls.RemoteHomePage"
DataContext="{Binding RelativeSource={RelativeSource Self}}"
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}">
<ScrollViewer>
<ScrollViewer.Content>
<StackPanel>
<TextBlock Txt="Text1" Sign="#" />
<TextBlock Txt="Text2" Sign="#" />
<controls:Divider />
<TextBlock Txt="Text3" Sign="~" />
<TextBlock Txt="Text4" Sign="~" />
<controls:TextDivider Text="Divider text" />
<phone:LongListSelector ItemsSource="{Binding Items}">
<phone:LongListSelector.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Title}" />
</DataTemplate>
</phone:LongListSelector.ItemTemplate>
</phone:LongListSelector>
</StackPanel>
</ScrollViewer.Content>
</ScrollViewer>
</staff:UserContentControl>
This solution satisfies my needs but also there's a big problem: currently LongListSelector takes really a lot of time to load when amount of items it contains is reasonably large. It takes 8 seconds to process 300 items and during that time the whole UI is blocked. If I remove everything but LongListSelector, like so:
<staff:UserContentControl
...>
<phone:LongListSelector ItemsSource="{Binding Items}">
<phone:LongListSelector.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Title}" />
</DataTemplate>
</phone:LongListSelector.ItemTemplate>
</phone:LongListSelector>
</staff:UserContentControl>
then LongListSelector loads almost immediately even with significantly larger amount of items. But obviously I need those other controls above it so the question is what can I do solve this issue?
(Also related question: I was worried that LongListSelector inside ScrollViewer could cause double scrolling or something like that but eventually everything turned out just fine in this regard. I'm not sure if LongListSelector somehow knows that it is inside other scrollable control or if something else happens that I'm not aware of. Some explainantion why it works fine, although very slow, would be much appreciated.)
Don't use scroll viewer since it will make the longlistselector think it has an infinitely tall screen available and render all its items.
Instead to solve your usecase use the Header and Footer properties to add data above or below your list items.
You can't force ScrollViewer to virtualize LongListSelector items.
So you need to mimic it behaviour by LongListSelector only.
Make the first item contains all you required elements form StackPanel (1'st itemtemplate). And other elements will be basic LongListSelector elements (2'nd itemtemplate).
Here is explanation how to set different templates to the items: Styling a selected ListViewItem in Windows 8 CP

Using AdControl in windows phone 7

How to make Adcontrol always visible at bottom of the screen. Right now it is going at the end of the screen.
I have pivot control, in it I have Listbox which is dynamically binding with data. After pivot control I have adcontrol. So when the data grows in Listbox, adcontrol goes down. How to make it fixed at the bottom.
Your root layout control should be a grid which wraps the pivot and ad control:
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<toolkit:Pivot Grid.Row="0">
<ListBox>
...
</ListBox>
</toolkit:Pivot>
<AdControl Grid.Row="1"/>
</Grid>
You can most certainly use the popup call and contain the ad in it. My solution below is using a canvas to hold the ad in which would net the same result, but may be more familiar with what you've used before.
Also, you don't have to set the height and width of your listbox/pivot container if you didn't want to. What the canvas/popup would do is be outside of the pivot control, so it is always on top of the stack.
For instance (approximating your code)
<Grid x:Name="LayoutRoot">
<controls:Pivot>
<!--PivotItemOne-->
<controls:PivotItem>
<Grid>
<!-- code -->
</Grid>
</controls:PivotItem>
....
</controls:Pivot>
<Canvas x:Name="Ad" VerticalAlignment="Bottom" Width="Auto" Height="80"/>
<!-- or whatever height you want depending on ad size -->
</Grid>
This way, the canvas is always at the bottom of the page and hovering over your pivot control. It will not matter if the pivot changes as it is outside of the Pivot control.
If you ever needed to get rid of the Ad visibility or destroying the container itself, it would require less work overall than changing your listbox/pivot size.

Weird behaivior of ProgressBar in WP7

So, I'm tryging to use a progress bar in my WP7 Panorama aplication.
There is one page, that is downloadidng data from the web, so I want to indicate that my App is doing something with ProgressBar
<controls:PanoramaItem Header="news">
<Popup Name="myWeatherPopup" IsOpen="False" Width="404" Height="Auto" Margin="0,136,4,293">
<StackPanel>
<ProgressBar Height="Auto" IsIndeterminate="True" Width="400" />
<TextBlock Text="Loading" HorizontalAlignment="Center" Foreground="Gray" />
</StackPanel>
</Popup>
</controls:PanoramaItem>
It basically works as it should. However, there is one tiny (and anoying bug).
The first... run (?) of the dots appears on every panorama item, just under header. After that, it returns on its normal position under news item.
The same thing happens on emulator and Lumia 800.
Image
Have you tried without the Popup, by just setting the Visibility property on the StackPanel?

WP7 - ListPicker in StackPanel in ScrollViewer

Just started with developing for WP7 and came across the following. I have a pivot application with a few pivotitems. On the first pivotitem (see code below) I want to be able to adjust a lot of settings. For this question all items to be set are called 'TextBox' and the choice in the ListPicker is either A,B or C.
Now if I do NOT use the ScrollViewer and I tap any of the listpickers I get to see all three options BUT I can not scroll through all listpickers.
If I DO use the ScrollViewer, I CAN see all listpickers but only the top one (that's visible) will expand and give me the options A,B and C, they others stay collapsed.
How can I get every listpicker to expand and show me the avaiable options AND be able to scroll to every listpicker on the page?
PS In code below copy the stackpanel between start and end about 15 times.
Thanks in advance for any help!
<controls:PivotItem Header="blabla">
<ScrollViewer>
<StackPanel Margin="0,0,36,0" VerticalAlignment="Top" d:LayoutOverrides="Width">
// start
<StackPanel Orientation="Horizontal">
<TextBlock TextWrapping="Wrap" Text="TextBox" Width="80" TextAlignment="Right" Margin="10,22,20,0" HorizontalAlignment="Right" VerticalAlignment="Top" />
<toolkit:ListPicker Margin="0" Width="275">
<toolkit:ListPickerItem Content="A"/>
<toolkit:ListPickerItem Content="B"/>
<toolkit:ListPickerItem Content="C"/>
</toolkit:ListPicker>
</StackPanel>
// end - copy/paste code code between start and end about 15 times right here
</StackPanel>
</ScrollViewer>
</controls:PivotItem>
This is, apparently, a common issue with Listpicker and ScrollViewer. You can find a workaround here
Should anybody stumble upon this, this has been fixed since the november 2011 release of the wP7 silverlight toolkit.

Windows Phone 7 dev: How to autoscroll textblock's text Horizontally

I have this textblock <TextBlock Text="{Binding Name}" TextWrapping="NoWrap" Margin="12,-3,12,0" FontSize="27"/> , and I want to tell me a way in order to text, scrolled automatically when it is longer than screen.
Wrap it in a ScrollViewer
<ScrollViewer>
<TextBlock Text="{Binding Name}" TextWrapping="NoWrap" Margin="12,-3,12,0" FontSize="27"/>
</ScrollViewer>
For those who still interest and wants to do one for yourself, please take a look at my article on How to create marquee TextBlock on Windows Phone
It uses Storyboard to perform animation so that all are handled by GPU
I agree that it isn't a good practice, but look at my answer if you really need it.

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