Prism Xamarin How to access my grid at runtime - xamarin.forms

I am developing with Prism library and Xamarin, I want to create a table which will be able to add new rows and fill the content in the new rows.
It seems there is no table control, and I made a test with Grid, I defined the Grid at xaml like below:
<Grid x:Name="SourceGrid" >
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition/>
</Grid.RowDefinitions>
</Grid>
But, how can I access this Grid after my application lauch at runtime.
I want to add new row while runtime.

First google for such made controls, there are some available from the community. Second please kindly read about creating xamarin custom controls it will answer much.
For the direct answer:
You can access its SourceGrid.Children with methods like SourceGrid.Children.Add(view, col, row);

Related

How to wrap long messages using Editor in Xamarin Forms

I am using Editor control and wish to wrap long messages (Like Whatsapp).
I have explored few sites and got nothing . If this feature is not yet in Xamarin Forms , can I know any alternative for the same ?
My XAML
<Editor Grid.Row="0" Grid.Column="0" Text="{Binding TextMessage}"
TextColor="{StaticResource StartColor}" HorizontalOptions="FillAndExpand"
FontSize="14" TextChanged="Editor_TextChanged"
FontFamily="{StaticResource DefaultFont}" IsEnabled="True"/>
OUTPUT-
I would first suggest you to use AutoSize property of Editor, so if you want your editor to automatically resize depending on the text length, you should set it to TextChanges, otherwise set it to Disabled(this is default value).
Next thing, if you know that the Editor will be used for chat, you can also set Keyboard property to Chat:
<Editor Text="Enter text here" AutoSize="TextChanges" Keyboard="Chat" />
If I am not mistaken, The Editor control has a property for this called the AutoSize Property which takes the EditorAutoSizeOption enum as an input. Available options are TextChanges and Disabled.
<Editor AutoSize="TextChanges"...
If for some reason this does not work for you then you can use the solution in this forum discussion. by ionixjunior.
For those who are still facing issues, I have a case where the line does not wrap as long as there is no break line (Enter). Solution was to change parent layout from StackLayout to Grid. With grid, now it works.
If you want the height to change dynamically when you have more lines, you can use the above solution:
AutoSize="TextChanges"

Xamarin NetStandard SfListview Item tapped event not firing?

This is just as the title suggests. I've updated my Xamarin Forms project to a 1.6 NetStandard project and now the tapped event on my SfListView isn't working (It just doesn't fire at all).
Does anyone has any suggestions of what could be wrong or have faced anything like this?
EDIT
this is xaml code for SfListView:
<StackLayout HeightRequest="15" Grid.Row="0" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand">
<xForms:SfListView Orientation="Horizontal" ItemSize="128" ItemsSource="{Binding Categories}" SelectionBackgroundColor="Transparent" IsScrollBarVisible="False">
<xForms:SfListView.ItemTemplate>
<DataTemplate>
<cells:CategoryCell />
</DataTemplate>
</xForms:SfListView.ItemTemplate>
<xForms:SfListView.Behaviors>
<behaviors:SfSelectedItemBehavior Command="{Binding FilterCommand}" />
</xForms:SfListView.Behaviors>
</xForms:SfListView>
</StackLayout>
this structure was working before the update. I use a behavior for item selection.
We have checked with the reported query “SfListView ItemTapped event does not trigger after updating the NetStandard Library” from our side. Unfortunately the reported issue does not occur at our end and the ItemTapped event is fired as expected.
For your reference, we have attached the working sample link below.
Sample link: http://www.syncfusion.com/downloads/support/directtrac/190562/ze/SfListViewSample-670965361
Can you please check in your device whether the issue reproduces in our sample also?
If so, Can you please share the below details?
Whether the reported issue occurs in particular device or all devices? (Can you please share the details of your tested device)
Whether the issue is produced in particular platform?
Whether the issue is produced in particular version of Xamarin.Forms and SfListView? (In our sample, we used XForms (v2.3.4.280) and SfListView(v15.3.0.33))
Also can you please share the share the template in which the SfListView items are loaded?

In custom WorkflowViewElement, how to support WF4.5 Annotations?

I've created a a custom activity designer, but I wanted to have control over the 'header' part (that by default shows the ModelItem.DisplayName), and as far I know, the only way to achieve this is to derive the designer from WorkflowViewElement rather than ActivityDesigner. So, that seems to work and all is well. Except, I want to support the new Annotations feature of WF4.5.
Given that when you add an annotation to a workflow element on the design surface it adds an icon to the element you are annotating + the actual annotation element, it seems clear that any custom WorkflowViewElement has to have some extra stuff in it to support this behaviour. Can anyone help?
Thanks
As I thought, annotations are saved within the workflow definition as an attached property. Here's what an annotation looks like in the workflow's xaml:
<Sequence
xmlns:derp="http://schemas.microsoft.com/netfx/2010/xaml/activities/presentation"
derp:Annotation.AnnotationText="This is an annotation!">
See, just like any other attached property. Except it isn't. Its an attached workflow property, not an attached DependencyProperty. That means it works through the attached property service as well as the Annotation class. Getting and setting the annotation text on a ModelItem is trivial (and covered below).
Its actually not that hard to support annotations. As long as you don't mind your UI looking like crap. Here's a quick and dirty implementation.
In the UI, add some controls for holding and editing the annotation text
<sap:WorkflowViewElement
x:Class="AnnotationSupport.MyActivityDesigner"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:sap="clr-namespace:System.Activities.Presentation;assembly=System.Activities.Presentation"
xmlns:ann="clr-namespace:System.Activities.Presentation.Annotations;assembly=System.Activities.Presentation"
xmlns:sapv="clr-namespace:System.Activities.Presentation.View;assembly=System.Activities.Presentation"
x:Name="root"
MinWidth="100"
MinHeight="100">
<Grid Background="red">
<Grid.RowDefinitions>
<RowDefinition
Height="auto" />
<RowDefinition />
</Grid.RowDefinitions>
<Expander
IsExpanded="False">
<!-- HERE SHE BLOWS -->
<TextBox
Text="{Binding ModelItem.AnnotationText}" />
</Expander>
<TextBox
Grid.Row="1"
Text="{Binding ModelItem.Text}"
Margin="10" />
</Grid>
</sap:WorkflowViewElement>
Any time the Annotation text changes, the ModelItem's PropertyChanged event fires, just like any other property. And if you want to grab it from code, the simplest way is to cast the ModelItem to a dynamic:
private void SetAnnotationLol(string newValue)
{
if(ModelItem != null)
((dynamic)ModelItem).AnnotationText = newValue;
}
Now, if you want to create a nice UI like the Fx Activities have... well...
I'll leave it up to you to create a custom Adorner to handle display and editing of the annotation. Which actually isn't as hard as it first looks. If you haven't done one yet, here's your opportunity.

Entity graphy binding not working in deep level

Suppose I have entity graph like
People ->Student
then in xaml, I have following kind of binding(People is property of VM):
<TextBox Text="{Binding People.Name, Mode=TwoWay}" />
<TextBox Text="{Binding People.Student.StudentNo, Mode=TwoWay}" /> <!-- this bounding is not working -->
in VM, implementing IEditableObject. I have some code like:
public void BeginEdit()
{
((IEditableObject)this.People).BeginEdit();
((IEditableObject)this.People.Student).BeginEdit(); //this code not working
//....
}
When runing the app, all data bound to People is fine.
All data bound to Student is not working.
How to fix it?
I'd guess that the Student property is null on the client side. You need to add the [Include] attribute to the Student property on the server-side, so that it gets taken across to the client side by RIA services. You may also need to add an include for your server-side to retrieve it from the database, depending on how your data-access is written.

WPF - Binding a variable in an already bound ListBox?

I really don't know how to title this question, but I need some help with binding to a ListBox.
I have an object, that contains (among other information) 2 properties that need to be bound in one ListBox. One of these is an ObservableCollection of objects, called Layers, and the other property holds an enum value of either Point, Line or Polygon, called SpatialType. These are to act as a legend to a map application. I have bound Layers to a ListBox, no problem, but inside the ListBox.ItemTemplate, I need to bind the single variable SpatialType to every Item in the ListBox. The problem I'm running into is that when I try to bind while inside the ListBox, the only variables I have access to are the properties of each Layer and I can't access any properties of the original bound class that holds the Layers (and the needed SpatialType property).
What can I do to get that piece of information bound inside the ItemTemplate without messing up a good MVVM architecture?
You can in your view have a ObjectDataProvider that is the basis for your datacontext and have the ObjectInstance point to your viewmodel. Then you can bind from the ItemTemplate like so:
<UserControl.Resources>
<ObjectDataProvider x:Key="Data"/>
<DataTemplate x:Key="Template">
<TextBlock Text="{Binding SpatialType,Source={StaticResource Data}}/>
</DataTemplate>
</UserControl.Resources>
<Grid DataContext={Binding Source={StaticResource Data}}>
<ListBox ItemsSource="{Binding Layers}" ItemTemplate="{StaticResource Template}"/>
</Grid>
Hope this helps.
What I ended up doing was using FindAncestor to get the DataContext of a higher "tier" in binding:
Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ListBox}}, Path=DataContext.LayerSymbolization.SpatialType, Mode=TwoWay}"

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