Almost every Xamarin.Forms mobile build I have done has required a “form” to be presented to the user. Whether it be for creating a new item in a task list, registering a new user, or other function, a point of frustration while constructing these views was there was no obvious way of setting focus to … Continue reading Building a “Next Entry” Effect for iOS and Android in Xamarin.

Les équipes de Xamarin Forms viennent de sortir la version 3.1 de Xamarin Forms, découvrons ensemble quelles nouveautés apporte cette version. Android : Le support des tabbed page en mode “bottom” Une fonctionnalité très attendue de la part de la communauté était de pouvoir utiliser les TabbedPage Android avec le menu en bas. Activer la fonctionnalité en C# : Activer la fonctionnalité en XAML : Améliorations pour le contrôle Entry/Editor : Les deux contrôles Entry et Editor ont été améliorés.

Xamarin.Forms 3.1 Con la llegada de Xamarin.Forms 3.1 llegan una gran cantidad de mejoras y correcciones (es genial ver que muchas vienen de la comunidad). Entre el conjunto de novedades tenemos la posibilidad de crear TabbedPage en la parte inferior en Android. En este artículo, vamos a ver como crear una Bottom TabbedPage. Bottom TabbedPage … Sigue leyendo →

Olá, neste post irei demonstrar como você pode implementar zoom nas imagens em suas aplicações Xamarin.Forms de uma maneira fácil e rápida utilizando custom renderer.   Comece criando a classe estática chamada “DoubleExtensions” no projeto compartilhado. DoubleExtensions.cs     Em seguida crie a classe “PinchToZoomContainer” em seu projeto compartilhado, ela será responsável em capturar o GestureStatus … Continue lendo Zoom em Imagens – Xamarin.

Earlier this week, on Tuesday, June 19th, our team had the chance to deliver a guest lecture on Xamarin to ICT students at Hanze University of Applied Sciences in Groningen. As part of their course, the students were introduced to several different mobile coding options. We were invited to provide an introduction to the Microsoft Xamarin platform. Marc Bruins, who ... Read More The post Bringing Xamarin to students in Groningen appeared first on XABLU.

Welcome to The Xamarin Show Snack Pack Edition. A Snack Pack is bite sized episode that is focused on a specific topic and covered in just a few minutes. In this Snack Pack we take a look at how the new simplified iOS device and app provisioning works inside of Visual Studio.Show Links:Introduction to fastlane for iOSfastlane on GitHubFind James on: Twitter, GitHub, Blog, and his weekly podcast Merge Conflict.

Developing Android applications is a unique experience, as it often involves taking advantage of the latest capabilities of Android while still providing backward compatibility to older Android devices in order to reach all potential users. This feat is accomplishable by using Android support libraries and doing runtime checks while using the latest APIs in the […] The post Getting Android Apps Ready for Google Play’s Target API Level Requirements appeared first on Xamarin Blog.

When using Xamarin Forms sometimes we have a control in our XAML that changes according to the value of a property in our model. For example, if we have a Label which property Text has a binding to a string property that represents a Name in a model that we want to be visible only […] The post Understanding Triggers in Xamarin Forms appeared first on XamGirl.

根據 Xamarin.Essentials 官方文件中指出：Xamarin.Essentials 跨平台應用程式開發介面的開發人員提供他們的行動應用程式。透過 Xamarin.Essentials 的套件幫忙，可以將這些功能整合到您的應用程式：加速計 應用程式資訊 電池 剪貼簿 指南針 資料傳輸 裝置顯示資訊 裝置資訊 電子郵件 檔案系統的協助程式 手電筒 地理編碼 地理位置 迴轉儀 磁力計 開啟瀏覽器 電話撥號員 喜好設定 螢幕鎖定 安全儲存體 SMS 文字轉換語音 追蹤版本 震動。我們現在來體驗關於 Geolocation 地理位置 這項功能，因此，可以參考底下的專案範例，該專案範例建立測試專案首先，我們先使用 Prism Template Pack 擴充功能所提供的專案樣板，建立起一個 Xamarin.Forms 專案，在這裡我們僅選擇 Android / iOS / UWP 類型的專案；接著，我們需要把 PropertyChanged.

Several years ago when I was still just a web developer wanting to break into mobile development, I asked myself how does anybody do this? You have to learn Java for Android, Objective-C or Swift for iOS.... of course then I learned about Xamarin. Without a doubt Xamarin makes the tedious tasks of mobile app development far easier by centralizing your code in one common language, and even further with Xamarin Forms by abstracting the UI into reusable code.

根據 Xamarin.Essentials 官方文件中指出：Xamarin.Essentials 跨平台應用程式開發介面的開發人員提供他們的行動應用程式。透過 Xamarin.Essentials 的套件幫忙，可以將這些功能整合到您的應用程式：加速計 應用程式資訊 電池 剪貼簿 指南針 資料傳輸 裝置顯示資訊 裝置資訊 電子郵件 檔案系統的協助程式 手電筒 地理編碼 地理位置 迴轉儀 磁力計 開啟瀏覽器 電話撥號員 喜好設定 螢幕鎖定 安全儲存體 SMS 文字轉換語音 追蹤版本 震動。我們現在來體驗關於 Clipboard 剪貼簿 這項功能，因此，可以參考底下的專案範例，該專案範例建立測試專案首先，我們先使用 Prism Template Pack 擴充功能所提供的專案樣板，建立起一個 Xamarin.Forms 專案，在這裡我們僅選擇 Android / iOS / UWP 類型的專案；接著，我們需要把 PropertyChanged.

Introducción El trabajo con datos en dispositivos móviles se ha convertido ya en algo común y habitual en el desarrollo de aplicaciones. Existe una gran variedad de tipos de datos y formas de almacenamiento: Archivos de texto. Texto plano o html cacheado en el espacio de almacenamiento aislado de la aplicación. Imágenes. En el espacio … Sigue leyendo →

Previously, I explained how to extend the FlexLayout class with ItemsSource and ItemTemplate properties, so that it can bind to data stored in a collection. However, the resulting ExtendedFlexLayout class is only a minimally viable implementation as it omits a number of required features. One of the missing features is that it doesn’t allow a DataTemplateSelector to choose a DataTemplate at runtime based on the value of a bound property.

根據 Xamarin.Essentials 官方文件中指出：Xamarin.Essentials 跨平台應用程式開發介面的開發人員提供他們的行動應用程式。透過 Xamarin.Essentials 的套件幫忙，可以將這些功能整合到您的應用程式：加速計 應用程式資訊 電池 剪貼簿 指南針 資料傳輸 裝置顯示資訊 裝置資訊 電子郵件 檔案系統的協助程式 手電筒 地理編碼 地理位置 迴轉儀 磁力計 開啟瀏覽器 電話撥號員 喜好設定 螢幕鎖定 安全儲存體 SMS 文字轉換語音 追蹤版本 震動。我們現在來體驗關於 Device Display Information 裝置顯示的資訊 這項功能，因此，可以參考底下的專案範例，該專案範例建立測試專案首先，我們先使用 Prism Template Pack 擴充功能所提供的專案樣板，建立起一個 Xamarin.Forms 專案，在這裡我們僅選擇 Android / iOS / UWP 類型的專案；接著，我們需要把 PropertyChanged.

Una recopilación de temas, tips, repasos y preguntas a problemas frecuentes a la hora de preparar aplicaciones para las principales tiendas de aplicaciones móviles: Google Play y Apple Store. Algunos aspectos importantes a preparar antes de publicar tu aplicación: Nombre adecuado Iconos (resoluciones y tamaños Android/iOS) Audiencia y tipo de aplicación Llaves de desarrollo y permisos Problemas frecuentes - Apple Store iTunes Store operation failed.

Apple has indicated that starting in July 2018 all new apps and app updates submitted to the App Store must be built with the iOS 11 SDK and support the iPhone X Super Retina display. The following resources describe how to make sure Xamarin.iOS apps look and work great with iOS 11 and iPhone X: […] The post Supporting iOS 11 and iPhone X in Xamarin.iOS Apps appeared first on Xamarin Blog.

En este artículo veremos de una manera fácil y rápida cómo implementar ventanas de despliegue personalizadas utilizando el paquete Rg.Plugins.Popup en una aplicación de Xamarin.Forms. Introducción Rg.Plugins.Popup  es un complemento multiplataforma para Xamarin.Forms que permite abrir páginas de Xamarin.Forms como una ventana emergente que se puede compartir en iOS, Android y UWP (el soporte de … Sigue leyendo Using Rg.

根據 Xamarin.Essentials 官方文件中指出：Xamarin.Essentials 跨平台應用程式開發介面的開發人員提供他們的行動應用程式。透過 Xamarin.Essentials 的套件幫忙，可以將這些功能整合到您的應用程式：加速計 應用程式資訊 電池 剪貼簿 指南針 資料傳輸 裝置顯示資訊 裝置資訊 電子郵件 檔案系統的協助程式 手電筒 地理編碼 地理位置 迴轉儀 磁力計 開啟瀏覽器 電話撥號員 喜好設定 螢幕鎖定 安全儲存體 SMS 文字轉換語音 追蹤版本 震動。我們首先來體驗關於 Device Information 裝置資訊 這項功能，在其官方文件中有提到：DeviceInfo類別會提供執行應用程式之裝置的相關資訊，因此，我們來練習如何使用這些功能。因此，可以參考底下的專案範例，該專案範例位於 https://github.

在這篇文章中，我們將會來探討這樣的頁面使用情境該如何進行設計，請參考下圖，在這個頁面中，將會有三個 Switch 控制項，我們希望能夠做到這三個控制項彼此之間的設定選擇是互斥的，也就是，類似一個 Radio Button 的變形應用；當我們選擇了 選項2 之後，選項1就會變成沒有被選擇狀態，同樣的，當選擇了 選項3，此時，選項1，選項2 就會變成沒有被選擇的狀態。本篇文章的範例程式碼 https://github.com/vulcanlee/xamarin-forms-sample2018/tree/master/XFDataChanged由於 Switch 這個控制項並沒有相對應可以使用命令 Command(其實，這個控制像是沒有提供任何的 命令)，這個時候，我們第一個想到的處理方式，就是使用 Prism 提供的 Behavior 行為機制 ， 您可參考 Using the EventToCommandBehavior ，設定當 Switch 的 Toggled 事件被觸發的時候，便可以執行 ViewModel 中指定的 DelegateCommand 的委派方法。不過，在這篇文章中，我們將要來說明另外一種做法，那就是使用我們安裝好的 PropertyChanged.

Neste post irei demonstrar como você pode utilizar Font Awesome em suas aplicações Xamarin.Forms. No momento em que escrevo este post o Font Awesome encontra-se em sua versão 5.0.13, então por isso esta versão será utilizada neste exemplo.   Download O primeiro passo é acessar o site do Font Awesome e realizar o download do … Continue lendo Font Awesome – Xamarin.Forms

根據 Xamarin.Essentials 官方文件中指出：Xamarin.Essentials 跨平台應用程式開發介面的開發人員提供他們的行動應用程式。透過 Xamarin.Essentials 的套件幫忙，可以將這些功能整合到您的應用程式：加速計 應用程式資訊 電池 剪貼簿 指南針 資料傳輸 裝置顯示資訊 裝置資訊 電子郵件 檔案系統的協助程式 手電筒 地理編碼 地理位置 迴轉儀 磁力計 開啟瀏覽器 電話撥號員 喜好設定 螢幕鎖定 安全儲存體 SMS 文字轉換語音 追蹤版本 震動。我們首先來體驗關於 File System Helpers 檔案系統的協助程式 這項功能，因此，可以參考底下的專案範例，該專案範例位於 https://github.com/vulcanlee/xamarin-forms-sample2018/tree/master/XFESFileSystem建立測試專案首先，我們先使用 Prism Template Pack 擴充功能所提供的專案樣板，建立起一個 Xamarin.

在這篇文章中，我們將需要使用 Xam.Plugin.Media 這個套件，讓您的 App 可以使用手機鏡頭來進行拍照，並且將這個拍照後的圖片儲存在該應用程式的沙箱 sandbox 資料夾內，之後，我們要使用 ImageSource 這個類別，把這個圖片檔案讀取出來，並且顯示在螢幕上，更多關於 Xam.Plugin.Media NuGet 套件的說明，可以參考 MediaPlugin本文章的範例專案位於 https://github.com/vulcanlee/xamarin-forms-sample2018/tree/master/XFMediaPlugin建立測試專案首先，我們先使用 Prism Template Pack 擴充功能所提供的專案樣板，建立起一個 Xamarin.Forms 專案，在這裡我們僅選擇 Android / iOS 類型的專案；接著，我們需要把 PropertyChanged.

The final day of the Build 2018 conference is here! I will tell you about the great and awesome sessions from day 3 and the final celebration in Museum of Pop Culture in Seattle! Last day of Build didn’t have any keynote, so we could all enjoy a bit longer rest in the morning. I had … Continue reading "Microsoft Build 2018 – Day 3"

Today we released the 3rd Preview for Prism 7.1. This is a very significant release for us and contains some very exciting changes. Forms Dependency Resolver At Build we released a special preview for Xamarin Forms. In that preview we released the much awaited ability to use your Application's DI Container to resolve types inside of Xamarin Forms such as your Renderers or Platform Effects. It was a great feature but there were some issues caused on Android by the transition from a default constructor to one that requires the Android Context.

When developing a chat UI in Xamarin Forms there are a few challenges we face: Having multiple UI cells Put the chat entry in the…Continue ReadingExploring a Chat UI in Xamarin Forms (Part. 1)

Welcome to The Xamarin Show Snack Pack Edition. A Snack Pack is bite sized episode that is focused on a specific topic and covered in just a few minutes. In this Snack Pack we take a look at Xamarin.Essentials, a powerful cross-platform library that provides a clean and lightweight API to access common features on mobile platforms, in your cross-platform C# apps without writing abstractions or platform-specific code.

We announced Xamarin.Essentials, a core set of cross-platform APIs to help developers build native apps, at Microsoft Build 2018. Xamarin.Essentials gives developers access to over thirty platform-specific APIs that can be accessed from their shared code, including geolocation, secure storage, sensors, device information, and many more. Best of all, Xamarin.Essentials can be used in any […] The post More Cross-Platform APIs with Xamarin.

In May we published a doc on the new FlexLayout control that’s present in Xamarin.Forms 3.0. FlexLayout is a versatile layout control that can arrange its children horizontally and vertically in a stack, and is also capable of wrapping its children if there are too many to fit in a single row or column. It also has options for orientation, alignment, and adapting to various screen sizes. In the FlexLayout guide we outlined some common usage scenarios, with one being a catalog of items that are displayed horizontally, which are navigated through by swiping in the appropriate direction.

So on iOS, UIScrollView bounces by default so in Xamarin.Forms the ScrollView natrually bounces. But what if you don’t want your ScrollView to bounce? Android doesn’t bounce, so we won’t worry about it. Let’s solve this problem with a custom renderer and control called NoBounceScrollView. This could also be done with an Effect but I … Continue reading Xamarin.Tip – No Bounce ScrollView in Xamarin.

If you want to use AOT-compiling (AOT = Ahead of Time) for your Xamarin.Android it requires that Android NDK (Native Development Kit) is installed on the machine that will build your app. I using VSTS to build my apps and I using the “Hosted VS2017” build agent. After I enabled AOT and LLVM (Low Level […]

One of the most important decisions that you’ll make when designing an app is what type of database to use. Not too long ago, the choice was limited to relational databases like SQL server. However, now NoSQL databases are on the scene with the benefits of allowing applications to handle large amounts of structured and […] The post Use MongoDB With Your Xamarin Apps appeared first on Xamarin Blog.

El día de hoy les quiero compartir una gran noticia, y es que llego un correo en donde se me indica que mi blog formara parte del top de los 50 Xamarin Blogs para desarrolladores de Xamarin del 2018. Xamarin Blogs List. The Best Xamarin blogs from thousands of top Xamarin blogs in our index … Sigue leyendo Top 50 Xamarin Blogs [VG] →

I previously mentioned that I’d published v1.4 of my Behaviors library, and that it included some new functionality. In my last blog post I looked at the SourceObject property that’s now present on the EventHandlerBehavior class. The final new item is the ConverterParameter property that now exists on the InvokeCommandAction class. The InvokeCommandAction class executes a specified ICommand when invoked.

相信大家對於如何在 Xamarin.Forms 中進行字串型別的資料綁定都非常的孰悉，今天，我們來練習如何進行圖片的資料綁定操作。我們的模擬情境為：當我們使用 HttpClient 進行非同步網頁讀取之後，便會變更要綁定的圖片內容，顯示出不同的圖片內容，這些圖片內容將會存在於原生專案。本文章的範例原始碼位於： https://github.com/vulcanlee/xamarin-forms-sample2018/tree/master/XFImgBinding首先，我們先建立的 Xamarin.Forms for Prism 的專案，並且完成 PropertyChanged.Fody 的套件安裝與設定工作，接著，要把這兩個圖片檔案 拖拉到各原生專案的圖片資源所在資料夾內，下圖示 Android 原生專案內的 Resource/drawable 資料夾，裡面就有這兩個圖片檔案。在這個範例中，僅有一個頁面，從底下的 XAML 內容中，我們可以很清楚的看到，圖片控制項 Image 的 Source 屬性，是綁定到 ViewModel 中的 ShowImage C# Property 上。另外，還有一個按鈕，當按下這個按鈕之後，就會透過 HttpClient 使用非同步的方式抓取 www.

Tutorial sencillo de cómo integrar estilos CSS con aplicaciones Xamarin.Forms incluido en la versión 3.0. El ejemplo disponible en GitHub.

Third article from my Build 2018 series focuses on day 2 of the conference. We will go through all the cool things from the first keynote, check out a few talks, get the best burger in Seattle and finish ourselves off with some yummy ice cream. Stay tuned! The second keynote is usually a bit … Continue reading "Microsoft Build 2018 – Day 2"

Resource Dictionaries En toda aplicación móvil la apariencia visual es vital. Cada vez es mayor el esfuerzo depositado a la hora de crear aplicaciones atractivas a la par que intuitivas y en muchos casos conseguir una imagen única que diferencia a la Aplicación del resto es prioritario. Por este motivo, debemos de contar con opciones … Sigue leyendo →

當我們想要進行 Xamarin.Android 專案封存 Archive 作業，並且要產生出可以發布佈署的 .apk 檔案，我們可以雙擊 Android 專案的 Properties 節點，進入到 Android 專案的屬性頁面；在這個頁面中，切換到 Android 選項標籤頁次，我們可以看到這三個選項將組譯碼組合成機器碼符合 AOT 規範 (實驗性)使用 LLVM 最佳化編譯器關於這三個項目的說明，可以參考準備可供發行的應用程式我曾在 2017.06 也寫過一篇類似的文章 Xamarin.Android 各種封存屬性測試 。當時所採用的測試專案為一個工作管理的範例專案，不過，今天，我們將會採用 Prism Template Pack 所提供的專案範本所產生的一個專案，這個專案內將沒有再去撰寫任何 C# / XAML 的程式碼。我的測試環境為 Visual Studio Enterprise 2017 15.

Xamarin.Forms: Custom Context Actions on iOSHello folks now is time to talk about customize context action views on Xamarin.Forms cell for iOS (yes the red/light-gray options that appear when you swipe a cell) the default colors are not a good-looking, so right now is a little bit tricky to achieve that but we will use a reflection technique to achieve the next two escenarios:Change background color for default and destructive context actionSet custom view for default and destructive context actionfirst at all, lets take a look to native impl.

Last few days I was working on more on UI design in one of the Xamarin.Forms projects. I tried to achieve same padding/margin around my labels and I seen that there is some extra padding at the top of the Label control on Android.So this will be very short blog post on how to decrease that extra padding above Label control.I have one simple Lable with BackgroundColor property set to Crimson color, just for showing how much space this label is using.

範例原始碼當我們在進行 Xamarin.Forms 專案開發的時候，ListView 是個相當重要的控制項，因為，他可以顯示一群資料在螢幕上，當集合資料顯示於 ListView 控制項，使用者可以點選任一紀錄，此時，ListView 控制項可以進行相對應的商業邏輯運作處理。另外，有些時候，我們希望能夠在 ListView 上，使用者可以長按紀錄，這個時候，期望會有一個彈出選項來讓使用者進行選擇，這個時候，我們就需要使用 ViewCell 的 ContextActions 功能。底下截圖是我們實際執行這個範例的結果，當使用者長按任何一筆 ListView 中的紀錄，這個時候，隨著這個 App 所運行的平台不同 (Android / iOS / UWP)，會出現不同的畫面，這裡我們是使用 Android 平台下執行的結果。所以，您會看到下圖右上方，會有兩個選項出現，使用者可以依照當時需求，點選這兩個選項的任何一個。在這個練習範例中，我們有實作出選項一與選項二這兩個功能，他分別會顯示一個對話窗出來。 首先，我們來看看 XAML 的標記語言宣告。我們在這個 ListView 中，使用了 ViewCell 宣告出每筆紀錄要顯示的內容，現在，我們可以在 ViewCell 控制項內，使用 ViewCell.

I previously mentioned that I’d published v1.4 of my Behaviors library, and that it included some new functionality. In my last blog post I looked at the GoToStateAction, which is the main item of new functionality. Another new item is the SourceObject property that now exists on the EventHandlerBehavior class. Prior to this addition, to use the EventHandlerBehavior you’d set the EventName property to the event that you want the behavior to listen to, and the EventHandlerBehavior would automatically look for this event on the VisualElement the behavior is attached to.

At Build 2018 we shipped Xamarin.Forms 3.0. Did you miss the announcement? No worries, you can watch it here to catch up on many of the great new things that will help make you more productive building cross-platform mobile applications with C# and Visual Studio. In the few weeks leading up to the release, David […] The post Build 2018: Conference Vision Demo App appeared first on Xamarin Blog.

Disclaimer: This sample code is intended for research and development use only. The sample code is not intended for use in clinical diagnosis or clinical decision-making or for any other clinical use and the performance of the sample code for clinical use has not been established.Mobile Chest X-Ray Analysis, a Microsoft Garage project, a Xamarin mobile solution that analyzes and interprets chest x-rays in real time using deployed machine learning models.

Expandable UITableViewCells with variable height, beautiful animations and no 3rd party libraries – all with just a few lines of code. Interested? Let me showRead more