Display png image xamarin.ios - xamarin.forms

I have a Xamarin.ios project running on Visual Studio for Imac.
I would like to display a png image file using XAML and C#. Would it be best to use a dependency service to construct the image object in C#?
code snippet:
<StackLayout Orientation="Horizontal">
<Image Name="MyImage" Width="180" />
</StackLayout>
I placed my png file in the assets.xcassents folder. The file name is picture.png. How would I get this code to display in the xaml? What would the
code look like. Thanks for your input.

In your case you can use the property Source of the Image tag in XAML. Than you are able to use the following code snippet:
<StackLayout Orientation="Horizontal">
<Image x:Name="MyImage" Source="picture.png" WidthRequest="180" />
</StackLayout>
And there was another issue in your XAML snippet, because the property Width is a readonly property for internal use by Xamarin.Forms. So if you want to specify the width of the image you must use the WidthRequest property.

Got the code working! Changed to BundleResouces and do not copy for the property on the image file. Also move image File to a separate folder.

Related

mvvmcross xamarin.forms PictureChooser

I am trying to develop a photo app using the PictureChooser plugin. I see that the sample uses Xamarin.iOS. I've googled for examples where the plugin uses Xamarin.Forms but can't find any. I understand how binding works for labels, text editors, and buttons; however, the binding btw the page's image control and the viewmodel's byte[] has got me stomped.
DAA.UI project:
In CameraPage.XAML:
<Image x:Name="MyImage"
Source="{Binding Bytes, Converter={StaticResource InMemoryImage}}"
Aspect="Fill"
HeightRequest="{OnPlatform iOS=300, Android=250}"
WidthRequest="{OnPlatform iOS=300, Android=250}"
HorizontalOptions="Center" />
In App.XAML:
<?xml version="1.0" encoding="utf-8" ?>
<Application
x:Class="DamageAssessmentApp.UI.App"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:d="clr-namespace:MvvmCross.Forms;assembly=MvvmCross.Forms"
xmlns:resources="clr-namespace:DAA.UI.Resources"
xmlns:local="using:DAA.UI"
xmlns:nativeValueConverters="using:DAA.UI.NativeValueConverters">
<Application.Resources>
<!-- Application resource dictionary -->
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<resources:Colors />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
<nativeValueConverters:NativeInMemoryImageValueConverter x:Key="InMemoryImage"/>
</Application.Resources>
</Application>
Value Converter file:
using MvvmCross.Forms.Converters;
namespace DAA.UI.NativeValueConverters
{
public class NativeInMemoryImageValueConverter : MvxNativeValueConverter<MvxInMemoryImageValueConverter>
{
}
}
The compiler can't find MvxInMemoryImageValueConverter in the value converter file.
If you are using MVVMCross you should find an example that works with Xamarin.Forms, in which case a good place to start it's their Github.
Or you have to implement it in each platform and use a DependencyService to get the implementation
Other Alternatives
Xamarin Community Toolkit
Another alternative for a camera App is Xamarin Community Toolkit Camera View. In that same link there is an example. But there are more examples in their Github. This is fully compatible with Xamarin.Forms and brings a little more control over the CameraView
Xamarin.Essentials
Xamarin.Essentials offers the MediaPicker that let's the user upload a photo from the gallery or take a new one. But the action of the photo in handled by the OS, so for you it's like a black box. You call the function, and get the photo.

Button Background is Transparent When Navigating to Page (UWP)

I have a very simple Xamarin Forms application that navigates between two pages.
On the second page (the page being navigated to) the following XAML content exists:
<StackLayout>
<Button Text="TEST" />
</StackLayout>
When the page has this content, the page appears to render correctly. However, if I change the XAML to this:
<StackLayout HorizontalOptions="CenterAndExpand" VerticalOptions="CenterAndExpand">
<Button Text="TEST" />
</StackLayout>
The button background appears to be transparent until I hover over the button. It appears that any combination of values for the HorizontalOptions and VerticalOptions properties causes this effect.
Interestingly, if I set the second page as the root page, the button background is not transparent even when the properties are set.
I am using the Prism framework if that makes any difference.
What am I missing? Is this behavior correct?
Should anyone stumble upon this question, I submitted an issue on GitHub (here). It has been confirmed as a bug.

Specify design time binding context in a GridTemplateColumn

I'm working on a Xamarin.Forms project. In my xaml page, order to avoid "Cannot resolve property 'xxx'" warning, I've set a design-time data context.
In this page I have a SfDataGrid object.
In the following code snippet, the text property of the custom entry is binding to the Quantity field of a Part item. The Parts object is an ObservableCollection<Part>.
<xForms:SfDataGrid ItemsSource="{Binding Parts}" AutoGenerateColumns="false" Margin="0"
ScrollingMode="PixelLine"
HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" >
<xForms:SfDataGrid.Columns>
<xForms:GridTextColumn MappingName="ProductName" HeaderText="Product"
HeaderTextAlignment="Start" ColumnSizer="Star"
TextAlignment="Start" Padding="5,0,5,0"/>
<!--#region Quantity column -->
<xForms:GridTemplateColumn MappingName="Quantity" HeaderText="Quantity"
HeaderTextAlignment="Center"
ColumnSizer="Auto" Padding="0" >
<xForms:GridTemplateColumn.CellTemplate>
<DataTemplate>
<controls:CustomEntry Text="{Binding Quantity, Mode=TwoWay,
Converter={StaticResource NullableDouble}}"
Keyboard="Numeric" HorizontalTextAlignment="Center"
VerticalOptions="End"/>
</DataTemplate>
</xForms:GridTemplateColumn.CellTemplate>
</xForms:GridTemplateColumn>
<!--#endregion -->
</xForms:SfDataGrid.Columns>
</xForms:SfDataGrid>
The warning is displayed under the Quantity word in Text={Binding Quantity, Mode...
What should I do to avoid the warning for the binding used in the cell templates?
Should I add a BindingContext="{d:DesignInstance models:Part}", or d:DataContext="{d:DesignInstance models:Part}" on each field ?
Hi Crusty Applesniffer,
Thanks for using Syncfusion Product.
We have checked your query with following details.
By using SfDataGrid have created the GridTemplateClolumn and added CustomEntry as DataTemplate in XAML page
Text property of this custom entry is binding to the double type
property named as OrderId
We have set this Text property binding
Mode as TwoWay, And we have written the converter for this property.
And we have added the Xaml
Complilation([XamlCompilation(XamlCompilationOptions.Compile)]) Tag in .cs of the XAML
class file.
But unfortunately, We are unable to reproduce the “Cannot resolve property 'xxx'" warning” from our side, So Kindly provide More details in order to reproduce the issue.
Have you enabled any Style Cop or FxCop rule set in your application
? If yes, Mention those rule set details.
Type of property you have used to bind the Custom Entry Text Property.
SfDataGrid product version that you are currently using.
If possible kindly provide us the Issue replicating sample or modify the attached sample to replicate the issue.
We have prepared the sample as per your requirement, Do check and let us know Is there anything needs to add more to reproduce “Cannot resolve property 'xxx'" warning” issue.
Sample Link : http://www.syncfusion.com/downloads/support/directtrac/general/ze/DataGrid-1806700714
Regards,
Vigneshkumar R

FFImageLoading CachedImage is not showing gif image

I am using xamarin forms for my app development. I am using FFimageloading for view gif file. I am using the following code in xaml file:
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="myproject.View.MasterDetailPage1Detail"
Icon="UEmlogotiny.png"
xmlns:ff="clr-namespace:FFImageLoading.Forms;assembly=FFImageLoading.Forms"
xmlns:ffSvg="clr-namespace:FFImageLoading.Svg.Forms;assembly=FFImageLoading.Svg.Forms"
xmlns:ffTransformations="clr-namespace:FFImageLoading.Transformations;assembly=FFImageLoading.Transformations"
>
....
<ff:CachedImage x:Name="Gif" Source="resource://UETrack.Beats.App.loader.gif" VerticalOptions="CenterAndExpand"
HorizontalOptions="CenterAndExpand"
WidthRequest="75" HeightRequest="75"
DownsampleToViewSize="True" IsVisible="True"/>
Change the Image Build Action to "Embedded Resource"
The gif image has showed on Orio. But not show in below Oreo.
Can anyone help me to resolve this issue.
Where did you add your image? To the Drawable folders? xxhdpi, etc?
If so,you can simple do:
Source="loader.gif"

Implementing UWP flyout splitview using masterdetailview in prism?

I am a complete noob to xamarin :)
So was wondering if someone could point me to right resources.
To be short, I want to implement something like this in prism using Xamarin MasterDetailPage.
Using the master detail sample here, the hamburger menu doesn't act as a fly out.
<MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
prism:ViewModelLocator.AutowireViewModel="True"
x:Class="HelloWorld.Views.MyMasterDetail">
<MasterDetailPage.Master>
<ContentPage Title="Default">
<StackLayout>
<Button Text="ViewA" Command="{Binding NavigateCommand}" CommandParameter="MyNavigationPage/ViewA?id=A" />
<Button Text="ViewB" Command="{Binding NavigateCommand}" CommandParameter="MyNavigationPage/ViewB?id=B" />
<Button Text="ViewC" Command="{Binding NavigateCommand}" CommandParameter="MyNavigationPage/ViewC?id=C" />
</StackLayout>
</ContentPage>
</MasterDetailPage.Master>
</MasterDetailPage>
Right now, though there is enough space, it shows something like
(just as a sample, I am not using SplitViewMenu at all)
I need icons/some small text to show initially and on clicking hamburger, it should expand (you know just like the first link/ groove music app behavior).
Tips?
Right now, though there is enough space, it shows something like
In my experience, if you have assigned the Symbol property for SimpleNavMenuItem, the possible reason is you haven't imported the Themes file Generic.xaml under Themes folder
This file includes templates, styles for custom controls. For example, for NavMenuItem's template, FontIcon's Glyph property needs to be assigned correctly here:
<DataTemplate x:Key="NavMenuItemTemplate">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="48" />
<ColumnDefinition />
</Grid.ColumnDefinitions>
<FontIcon FontSize="16" Glyph="{Binding Path=SymbolAsChar}" VerticalAlignment="Center"
HorizontalAlignment="Center" ToolTipService.ToolTip="{Binding Path=Label}" />
<TextBlock Grid.Column="1" Text="{Binding Path=Label}" VerticalAlignment="Center" />
</Grid>
</DataTemplate>
While SimpleNavMenuItem class's SymbolAsChar property is based on Symbol's value:
public sealed class SimpleNavMenuItem : INavigationMenuItem
{
......
public Symbol Symbol { get; set; }
public char SymbolAsChar => (char) Symbol;
......
}
And if you still can make it work, please share a demo:)
I've sort of been looking for something like this myself since I can't hide the NavigationBar shown in the Master page of the MasterDetailPage when i run it on a Windows 10 Mobile device (I can hide for PC though). So basically, I'm looking into eventually building my own version of the MasterDetailPage.
Since I have not built it yet, I can't tell you exactly how to achieve what you're asking, but I do know that it will require you to either:
Write your own custom renderer for MasterDetailView or,
Write a new control and its renderer
In both cases, your renderer will involve creating and manipulating a new SplitView (which is the native UWP control that your SplitViewMenu example is extending). There's a tutorial for creating the actual UWP control here. If you havent learned about Xamarin's renderers yet, they are the "Translator" and "Interpreter" between a Xamarin.Forms control and a given platform's native control. I suspect Xamarin will eventually rewrite their MastDetailPage renderer for UWP to use a SplitView as a base, but who knows when that will be. Xamarin also has an open source SDK for Xamarin.Forms (as well as the others) on GitHub so you can study the MasterDetailPageRenderer for UWP.

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