Just a beginner question about what is the equivalent to FrameLayout (Android) in Xamarin.Forms?
FrameLayout is a control that is designed to contain a single child but can optionally have multiple children that are controlled with gravity or what works similar to zindex.
I don't think there is a direct map from xamarin.Forms to Framelayout.
if your just looking for a page level container for a single control there is:
Frame-An element containing a single child, with some framing options. Frame have a default Xamarin.Forms.Layout.Padding of 20.
ScrollView-An element capable of scrolling if it's Content requires.
If your looking for a Multiple Item Container the options are:
Grid -A layout containing views arranged in rows and columns.
RelativeLayout -A Layout that uses Constraints to layout its children.
StackLayout - A Layout that positions child elements in a single line which can be oriented vertically or horizontally. This layout will set the child bounds automatically during a layout cycle. User assigned bounds will be overwritten and thus should not be set on a child element by the user.
see:https://developer.xamarin.com/guides/cross-platform/xamarin-forms/controls/layouts/
However none of these support the Z-Index like ability of FrameLayout the best option at the moment is a Grid with a single element. The children will layout from back to front in the order they are in the Grids.Children stack.
Related
I have seen that most of the people use FrameLayout for loading Fragments.My question is Why FrameLayout ? and why not the others like LinearLayout,RelativeLayout or ConstraintLayout.Most of the answers on StackOverflow says FrameLayout is designed to block out an area on the screen to display a single item. But the others can also block the whole screen if the its height and width set to match_parent.What is the difference ?Why most of the people choose FrameLayout if others can do the same job ?
Thanks in advanceCheers
You can use anything (LinearLayout, RelativeLayout or ConstraintLayout).
FrameLayout is just the most basic ViewGroup that provides the least functionality. It is ideal to use if you only need to hold a single child - in this case, a fragment.
FrameLayout To load child one above another, like cards inside a frame, we can place one above another or anywhere inside the frame.
Designed to display a stack of child View controls. Multiple view controls can be added to this layout. This can be used to show multiple controls within the same screen space.
LinearLayout Designed to display child View controls in a single row or column. This is a very handy layout method for creating forms.
RelativeLayout Designed to display child View controls in relation to each other. For instance, you can set a control to be positioned “above” or “below” or “to the left of” or “to the right of” another control, referred to by its unique identifier. You can also align child View controls relative to the parent edges.
For more information, please check this
https://developer.android.com/guide/topics/ui/declaring-layout#CommonLayouts
I hope it's helpful to you!
I'm not so much good at programming but I can give you some reasons.
First, have a look at official docs.
In order to replace one fragment with another, the activity's layout includes an empty FrameLayout that acts as the fragment container. https://developer.android.com/training/basics/fragments/fragment-ui#AddAtRuntime
This means for switching between multiple fragments we have to use FrameLayout. Why Framelayout then? Another look at the official docs.
FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other. You can, however, add multiple children to a FrameLayout and control their position within the FrameLayout by assigning gravity to each child, using the android:layout_gravity attribute.
https://developer.android.com/reference/android/widget/FrameLayout.html
It can block out an area of the screen to display a single item. Other layouts could do the same thing too. So Frame?
Because FrameLayout has one characteristic that other layouts don't have.
FrameLayout can hold its child one above another, like a deck of cards. In a deck of cards, one card is placed above other.
FrameLayout does the same job. When you use FrameLayout as a fragment container it holds the child fragment one above other as your code wants. Then it shows one and left others behind it, you switch back to other fragments then it comes above and others go behind again.
That's all I know.
I am new to Android Development, so what is meant by child in the below paragraph....
A ScrollView is a FrameLayout, meaning you should place one child in
it containing the entire contents to scroll; this child may itself be
a layout manager with a complex hierarchy of objects. A child that is
often used is a LinearLayout in a vertical orientation, presenting a
vertical array of top-level items that the user can scroll through.
https://developer.android.com/reference/android/widget/ScrollView.html
In android (and most other technologies), views can have subviews, aka "children". Most views can have children and can be a child of a parent view. It's kind of like a "tree".
The most obvious feature of being a child of some other view is that the child moves with the parent view. Another feature is that the child is in the coordinate space of the parent view.
Your paragraph here basically says you can only put one child view in ScrollView and it is usually a LinearLayout. But don't be fooled! This child can have its own child views.
Gaurav i think this is what you looking for, you need to use only one LinearLayout tag inside ScrollView tag, if you are using more than one LinearLayout than it will show error. If you want to use more LinearLayout tag you can use them inside LinearLayout tag which is inside ScrollView tag. May be this will help you.
You need to understand the general concept of child and parent . Simply you can think of the real life relation between parent and child.on the hierarchy parents are toplevel and child is below.so when you come to android layout parent is container and child is the content.
i have very basic knowledge about the framelayout . i wants to implement two listviews in a One frame Layout plus and the condition is whenever i click any of list out of two list in a frame layout "the clicked list must get zoomed out to fill the screen".
This is not the correct way to do this, if you've read the FrameLayout doc you'd see this:
FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other. You can, however, add multiple children to a FrameLayout and control their position within the FrameLayout by assigning gravity to each child, using the android:layout_gravity attribute.
What you want to use is fragments.
I hope this helps.
there are many question about "FrameLayout". But i need the exact use of this different from LinearLayout, RelativeLayout. And in a project when we have to use this?
FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other. You can, however, add multiple children to a FrameLayout and control their position within the FrameLayout by assigning gravity to each child, using the android:layout_gravity attribute.
LinearLayout arranges elements side by side either horizontally or vertically(rows vs columns).
RelativeLayout is a layout manager that helps you arrange your UI elements based on some rule. You can specify thisngs like: align this to parents left edge, place this to the left/right of this elements etc.
Check these links
http://logc.at/2011/10/18/when-to-use-linearlayout-vs-relativelayout/
http://developer.android.com/reference/android/widget/FrameLayout.html
I am confused about the difference between LinearLayout, RelativeLayout, and AbsoluteLayout.
Could someone please tell me the exact differences between them?
LinearLayout means you can align views one by one (vertically/ horizontally).
RelativeLayout means based on relation of views from its parents and other views.
ConstraintLayout is similar to a RelativeLayout in that it uses relations to position and size widgets, but has additional flexibility and is easier to use in the Layout Editor.
WebView to load html, static or dynamic pages.
FrameLayout to load child one above another, like cards inside a frame, we can place one above another or anywhere inside the frame.
deprecated - AbsoluteLayout means you have to give exact position where the view should be.
For more information, please check this address https://developer.android.com/guide/topics/ui/declaring-layout#CommonLayouts
Definitions:
Frame Layout: This is designed to block out an area on the screen to display a single item.
Linear Layout: A layout that arranges its children in a single column or a single row.
Relative Layout: This layout is a view group that displays child views in relative positions.
Table Layout: A layout that arranges its children into rows and columns.
More Information:
FrameLayout
FrameLayout is designed to block out an area on the screen to display a single item. Generally, FrameLayout should be used to hold a single child view, because it can be difficult to organize child views in a way that's scalable to different screen sizes without the children overlapping each other. You can, however, add multiple children to a FrameLayout and control their position within the FrameLayout by assigning gravity to each child, using the android:layout_gravity attribute.
Child views are drawn in a stack, with the most recently added child on top. The size of the FrameLayout is the size of its largest child (plus padding), visible or not (if the FrameLayout's parent permits).
RelativeLayout
A RelativeLayout is a very powerful utility for designing a user interface because it can eliminate nested view groups and keep your layout hierarchy flat, which improves performance. If you find yourself using several nested LinearLayout groups, you may be able to replace them with a single RelativeLayout.
(Current docs here)
TableLayout
A TableLayout consists of a number of TableRow objects, each defining a row (actually, you can have other children, which will be explained below). TableLayout containers do not display border lines for their rows, columns, or cells. Each row has zero or more cells; each cell can hold one View object. The table has as many columns as the row with the most cells. A table can leave cells empty. Cells can span columns, as they can in HTML.
The width of a column is defined by the row with the widest cell in that column.
Note: Absolute Layout is deprecated.
LinearLayout : A layout that organizes its children into a single horizontal or vertical row. It creates a scrollbar if the length of the window exceeds the length of the screen.It means you can align views one by one (vertically/ horizontally).
RelativeLayout : This enables you to specify the location of child objects relative to each other (child A to the left of child B) or to the parent (aligned to the top of the parent). It is based on relation of views from its parents and other views.
WebView : to load html, static or dynamic pages.
For more information refer this link:http://developer.android.com/guide/topics/ui/layout-objects.html
LinearLayout - In LinearLayout, views are organized either in vertical or horizontal orientation.
RelativeLayout - RelativeLayout is way more complex than LinearLayout, hence provides much more functionalities. Views are placed, as the name suggests, relative to each other.
FrameLayout - It behaves as a single object and its child views are overlapped over each other. FrameLayout takes the size of as per the biggest child element.
Coordinator Layout - This is the most powerful ViewGroup introduced in Android support library. It behaves as FrameLayout and has a lot of functionalities to coordinate amongst its child views, for example, floating button and snackbar, Toolbar with scrollable view.
Great explanation here:
https://www.cuelogic.com/blog/using-framelayout-for-designing-xml-layouts-in-android
LinearLayout arranges elements side by side either horizontally or vertically.
RelativeLayout helps you arrange your UI elements based on specific rules. You can specify rules like: align this to parent’s left edge, place this to the left/right of this elements etc.
AbsoluteLayout is for absolute positioning i.e. you can specify exact co-ordinates where the view should go.
FrameLayout allows placements of views along Z-axis. That means that you can stack your view elements one above the other.