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102 Cards in this Set
- Front
- Back
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What ConnectivityManager property is used on Android to detect network connection? |
ActivityNetworkInfo |
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In REST, what header field determines the format of the response body? |
content-type |
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What is an idempotent HTTP method? |
A method that will always return the same result regardless of how many times it is called. |
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What does HttpClient.GetAsync() method return? |
HttpResponseMessage, including headers, content and status. |
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What two message handlers can be used with Xamarin.iOS to customize HttpClient and integrate more deeply with the networking stack? |
CFNetworkHandler and NSUrlHandler (better) |
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What message handler can be used with Xamarin.Android to to customize HttpClient and integrate more deeply with the networking stack? |
AndroidClientHandler |
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What info.plist key is used to add App Transport Security (ATS) exclusions for iOS? |
NSAppTransportSecurity |
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In what StackLayout orientation are some child LayoutOptions ignored, and what are those LayoutOption values. |
In the SAME direction as its orientation (horizontal or vertical) StackLayout ignores the Start, Center, End and Fill layout options. |
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What's the difference between StaticResource and x:Static markup extensions? |
StaticResource returns an object from a resource dictionary while x:Static accesses a public static field, static property, or constant defined by a class or structure, or an enumeration member |
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What are the dedicated APIs on Android, iOS and Windows for controlling the native visualappearance of an app. |
Windows – Style +ControlTemplate iOS – UIAppearance Android –android:theme |
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What two Android types are needed to start an Activity? |
Context and Intent Context: an access point to the Android environment running your app Intent: request sent to Android to start an new Activity To start a new Activity, create an Intent and pass it to Context.StartActivity() |
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PlatformEffect provides what three properties to allow access to visual customization? |
Container (UIView) Control (UIView) Element (Xamarin.Forms element) |
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When creating a custom Effect, what PlatformEffect method should be overridden to make changes to visual properties? |
OnAttached |
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What is the file location for the app-specific sandbox on Android, iOS and Windows? |
Android - *apphome*/files iOS - *apphome*/Library/[subdirectory] Windows - *apphome*\local |
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What object should be created to access a SQlite database? |
SQLiteConnection |
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For each platform, in what folder is a SQLite database stored? |
Android - *apphome*/databases iOS - *apphome*/Library Windows - *apphome*\LocalState |
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What method is used to set the threading mode for SQLite? |
SQLiteConnection.SetConfig(SQLiteConnection.Serialized); |
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SQLite.NET includes an asynchronous API through what class? |
SQLiteAsyncConnection |
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When querying SQLite.NET, what method can be used to stay on the background thread after await finishes? |
ConfigureAwait(false) |
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What two ways are there to tell the linker to keep something? |
In code, with a [Preserve] attribute. XML linker configuration file, linkerconfig.xml. |
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What are the distribution packages for iOS, Android and Windows? |
iOS - .app App Bundler Android - .apk App Package Windows - .appx AppX Package |
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When building an iOS app, what is the Deployment Target represent? |
Deployment Target is the minimum version of iOS required for that app to run. |
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What are the four types of Apple provisioning profiles? |
iOS App Developer Ad Hoc App Store Enterprise |
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In the Android build settings, what is the Target Framework? |
Target Framework controls the libraries the compiler uses when building an app. This should be set to the latest released framework. |
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In the Android build settings, what is the Target Android version? |
Target version is the Android version an app is intended to run on (used at runtime). This is typically the version on which the app will run the best. |
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What does an Android application package (.apk) contain? |
An .apk file contains your IL code, runtime, framework assemblies,native .dex files, manifest, resources (images, etc), ABIs and any componentsthe app uses. |
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In data binding, what method is used to associate a binding to a target property? |
BindableObject.SetBinding() nameEntry.SetBinding(Entry.TextProperty, nameBinding); |
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What markup extension is used to set a view as the binding source or BindingContext of another view in the same XAML page? |
x:Reference markup extension |
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In Xamarin.Forms what method is used to switch to the UI thread? |
Xamarin.Forms.Device.BeginInvokeOnMainThread |
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In Xamarin.Android what method is used to switch to the UI thread? |
Android.App.Activity.RunOnUiThread |
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In Xamarin.iOS what method is used to switch to the UI thread? |
InvokeOnMainThread or BeginInvokeOnMainThread |
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What ListView property should be set to enable "pull-to-refresh" to get new data? |
IsPullToRefreshEnabled |
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What are the built-in Cell types available in a DataTemplate? |
TextCell EntryCell ImageCell SwitchCell |
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What two ListView properties are used to change the line that separates each item? |
SeparatorVisibility and SeparatorColor |
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In a ListView, a cells ContextActions collection property contains objects of what type? |
MenuItem |
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Individual ListView rows can be resized programmatically at runtime using what method on the cell? |
ForceUpdateSize() |
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To conditionally provide a ListView with DataTemplate at runtime, the ItemTemplate property must be set to a derivation of what base class? |
Xamarin.Forms.DataTemplateSelector |
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What can be used to modify a DataTemplate definition at runtime? |
DataTrigger |
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When a ListView's HasUnevenRows property is true, what is the priority for which value determines row height. |
ViewCell.Height RowHeight (if ViewCell.Height = 0) |
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When using MVVM, how can a ListView's header and footer be defined? |
HeaderTemplate or FooterTemplate can be set with a DataTemplate. |
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What ListView property can be set to provide visual grouping of data? |
IsGroupingEnabled |
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What ListView property is used to get or set the binding to use for display the group header. |
GroupDisplayBinding |
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On iOS and Windows, what ListView property can be set to enable the "quick index" feature? |
GroupShortNameBinding |
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What ListView caching strategy generates a Cell for every item in the list and keeps them? |
RetainElement |
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What ListView caching strategy re-uses cells as the user scrolls through the list? |
RecycleElement |
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When is the RetainElement caching strategy on a ListView preferred? |
If you have a large number of bindings on the cell (e.g. > 20) ..or if the cell visuals change a lot based on the binding context ..or if testing shows that RecycleElement is slower for you |
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What three items should match between publisher and subscriber in order for messages to be received using MessageCenter? |
sender type message string parameter type |
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What are the three ICommand members that must be implemented? |
bool CanExecute() void Execute() event EventHandler CanExecuteChanged |
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What Xamarin.Forms controls expose a Command property? |
Button Menu ToolbarItem TextCell |
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How do you apply an Effect to a control in code? |
Effect effect = Effect.Resolve("Company.MyEffect"); myButton.Effects.Add(effect); |
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What the three overridable methods in the PlatformEffect base class are use when creating a custom effect? |
OnAttached OnDetached OnElementPropertyChanged |
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What assembly level attributes (platform specific) are required to set an effect identifier? |
[assembly: ResolutionGroupName("MyCompany")] [assembly: ExportEffect(typeof(MyIOSShadowEffect), "ShadowEffect")] |
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What assembly level attribute ties an effect name to the platform-specific class that implements the effect? |
ExportEffect |
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What extension methods are used to embed a native control in a Xamarin Forms layout control and content control? |
layout control - Use the Add extension method Use the ToView extension method to convert and add all at once content control - Use the ToView extension method to convert, then load manually |
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What are the three steps to customize a renderer? |
1. Subclass an element 2. Subclass the platform renderer for the element on each platform 3. Use the assembly-level ExportRenderer attribute to connect the Xamarin.Forms element to the platform-specific renderer |
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What method is overridden when customizing a platform renderer for an existing control? |
OnElementChanged |
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When creating a renderer for a custom control, what base method is used to set the Control property? |
SetNativeControl |
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When implementing a platform-specific renderer, what type parameters are used when deriving from the base ViewRenderer class? |
Type of the custom Xamarin.Forms element Type of the custom native control |
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When creating a renderer for a custom control, what method is overridden to create an instance of the control? |
OnElementChanged |
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When creating a renderer for a custom control, what base ViewRenderer property exposes the Xamarin.Forms custom element? |
base.Element |
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What custom renderer method should be overridden to monitor property changes on the Xamarin.Forms element? |
OnElementPropertyChanged |
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For iOS, how can you make an image appear on a control? |
TabBarItem.Image = UIImage.FromBundle ("MyImage"); |
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What control is used to display an image in an iOS storyboard? |
UIImageView |
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In iOS, what are the responsibilities of a UIView? |
Visualization Layout for subviews Event publishing |
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In iOS, what are the responsibilities of a UIViewController? |
1. provides view management for a single screen 2. owns a UIView (root view) and receives lifetime notifications from it 3. Acts as the mediator between the view(s) and the data/logic/model(s) |
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What is an outlet in iOS? |
An outlet is a property that is tied to a control in the UI design. |
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What is required to build a Xamarin.iOS app? |
the latest iOS SDK the latest version of Xcode Mac OS X Yosemite(10.10) & above |
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What .NET API/features are not available for Xamarin.iOS? |
System.Configuration System.Reflection.Emit System.Runtime.Remoting No support for creating types dynamically |
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What interface should be implemented when making UI thread calls from shared code? |
IDispatchOnUIThread |
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What common platform features are accessible using the Xamarin.Mobile component? |
reading address book get user's location take a photo |
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What social networks does the Xamarin.Social component work with? |
App.net Flickr |
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For a child element of a StackLayout what are the default HorizontalOptions and VeriticalOptions values? |
Fill |
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In the direction opposite of its orientation, what child layout options does a StackLayout use? |
Start Center End Fill |
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What is the relationship between a StackLayout's orientation and expansion? |
A StackLayout can expand in the same direction as its orientation. A StackLayout ignores "AndExpand" in the opposite direction of its orientation. |
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In the same direction of its orientation, what child layout options does a StackLayout use? |
"...AndExpand" version of a layout option is used Start, Center, End and Fill are ignored |
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Which HTTP methods are idempotent? |
OPTIONS GET HEAD PUT DELETE |
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What is a safe HTTP method? |
Safe HTTP methods do not modifythe resource representation. |
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Which HTTP methods are safe? |
OPTIONS GET HEAD |
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In what ways can the native control rendering be modified? |
Platform themes Effects Embedded native controls Custom renderers |
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What does the ExportEffect attribute do? |
It ties the effect name with the platform-specific class that implements that effect. [assembly: ExportEffect(typeof(MyIOSShadowEffect), "ShadowEffect")] |
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What is Frame when positioning a subview in iOS? |
Frame defines the view position and size in superview coordinates. |
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What is Center when positioning a subview in iOS? |
Center defines the center point of the view in superview coordinates. |
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What is Bounds when positioning a subview in iOS? |
Bounds defines the position and size of the view in it's own coordinates. |
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On iOS, what is in the Entitlements.plist file? |
external Apple services your app wants to interact with such as in-app purchases, HealthKit or push notifications |
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On iOS, what file is responsible for creatingthe main window and listening to operatingsystem events? |
AppDelegate.cs |
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What are the Register, Outlet and Export attributes for in iOS? |
Classes that will be instantiated by iOS need to be registered with theObjective-C runtime with the Register attribute. An outlet is a property that is tied to a control in the UI design. Export attribute exports a method or property to the Objective-C world. |
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In AppDelegate, what is done when overriding the FinishedLaunching method. |
create new UIWindow, assign to Window property instantiate custom ViewController and assign to RootViewController call Window.MakeKeyAndVisible() |
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In an iOS ViewController, what method is called after a view is loaded. |
ViewDidLoad() this is the place to add new controls and set any visual properties |
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On iOS, what UITextField method should be called to dismiss the keyboard? |
ResignFirstResponder() |
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In Android, what is an Activity? |
An Activity defines the UI and behavior for a single task. |
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In Android, what are the two special values for specifying layout_width and layout_height on a LinearLayout? |
match_parent - same size as the parent view wrap_content - just large enough to fit around its content |
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What is the baseline density on Android? |
160dpi 1dp = 1px on a 160 dpi screen |
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How is an Android app's main Activity designated? |
The class that inherits from Activity should have the [Activity] attribute with MainLauncher property set to 'true'. |
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What method should be overridden to initialize an Android Activity? |
OnCreate() |
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On Android, what method instantiates all the Views in a layout file and loads them as the Activity's UI? |
protected override void OnCreate(Bundle bundle) { base.OnCreate(bundle); SetContentView(Resource.Layout.Pi); } |
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How do you set the id on an Android view? |
Set the Id of a View in XML using the id attribute and the syntax @+id/ android:id="@+id/myView" |
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What is a Bundle in Android? |
A Bundle is a collection of key - value pairs passed between activities. Extras are a Bundle inside an Intent to be passed between Activities. |
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What are the two ways to load Intent Extras? |
intent.PutExtras(bundle);
intent.PutExtra("ContactId", 123456789); |
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What are two equivalent ways to retrieve Intent Extras in the Target? |
int id = base.Intent.Extras.GetInt("ContactId", -1); int id = base.Intent.GetIntExtra("ContactId", -1); |
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What method should a source Activity override to start a target activity and pass it a request code? |
StartActivityForResult(intent, requestCode); |
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What method should a source Activity override to receive results from a target activity? |
OnActivityResult(requestCode, resultCode, data); |
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What are the different pieces of info that can be loaded into an Implicit Intent? |
Action - specifies what needs to be done Data - piece of info for Target Activity Categories - restricts the kind of Activity you would like to handle your Intent MIME Type - indicates the type of the Data you want the Intent to manipulate, it helps Android determine which Activity to launch Extras |
