What is findViewById used for?
Finds a view that was identified by the android:id XML attribute that was processed in #onCreate .
How do I stop findViewById on Android?
Use view binding in an Activity
You don’t have to call findViewById when using view binding — instead just use the properties provided to reference any view in the layout with an id. The root element of the layout is always stored in a property called root which is generated automatically for you.
What is the use of Find view by ID in android?
The Android SDK provided a method: findViewById() . Functionality-wise, this method performs a singular task — it will give you the reference to the view in XML layouts by searching its ID. And if nothing is found, it will give you the good old NULL , which is said to be the 1-billion dollar mistake by its creator.
What is Android padding?
The padding is expressed in pixels for the left, top, right and bottom parts of the view. Padding can be used to offset the content of the view by a specific number of pixels. For instance, a left padding of 2 will push the view’s content by 2 pixels to the right of the left edge.
What is the return type of findViewById?
As a point, findViewById function return a view instead of it’s sub view, i think you are confused return value and information get from getClass. The output of findViewById(R. id. mainListView).
What does setOnClickListener do in Android?
One of the most usable methods in android is setOnClickListener method which helps us to link a listener with certain attributes. While invoking this method a callback function will run. One can also create a class for more than one listener, so this can lead you to code reusability.
Should I use ViewBinding?
In case you just need to access views in your Java code without any complex/repeating view logic (eg: change visibility of multiple views on basis of one data variable), then you should use ViewBinding as it is lighter and faster.
How do I replace findViewById?
Youtube quote: Use the new view binding library to replace fine view by D in your app. It lets you write concise. Safe code with less boilerplate. Instead of having to look up every view it generates a binding
What is Parcelize in Kotlin?
On Android, Parcelable is an interface that a class can implement to be passed within an Intent from an Activity to another one, this way, transporting data from one Activity to another one. To achieve this your class must implement the Parcelable and override some methods.
What is Match_parent and Wrap_content in Android?
FILL_PARENT (renamed MATCH_PARENT in API Level 8 and higher), which means that the view wants to be as big as its parent (minus padding) WRAP_CONTENT, which means that the view wants to be just big enough to enclose its content (plus padding) an exact number.
What is difference between margin and padding?
In CSS, a margin is the space around an element’s border, while padding is the space between an element’s border and the element’s content. Put another way, the margin property controls the space outside an element, and the padding property controls the space inside an element.
What is the difference between margin and padding Android?
The main difference between the padding and margin is: Padding provides the space between the border and the content of an element. Margin provides the space between the border and outer elements.
Will margins collapse?
The top and bottom margins of blocks are sometimes combined (collapsed) into a single margin whose size is the largest of the individual margins (or just one of them, if they are equal), a behavior known as margin collapsing. Note that the margins of floating and absolutely positioned elements never collapse.
What is padding in UI?
Padding refers to the space between UI elements. Padding is an alternative spacing method to keylines and is measured in increments of 8dp or 4dp. Padding can be measured both vertically and horizontally and does not need to span the whole height of a layout. A layout with 24dp padding between components.
What is the difference between gravity and Layout_gravity in Android?
So in general android:layout_gravity attribute is used by child views to tell their parent how they want to be placed inside it, while android:gravity is used by the parent layout to tell the child views how they should be placed inside it.
Why gravity alignment is used?
The android:gravity attribute is used to arrange the position of the content inside a view (for example text inside a Button widget). The android:layout_gravity is used to arrange the position of the entire View relative to it’s container.
What is android Layout_weight?
LinearLayout also supports assigning a weight to individual children with the android:layout_weight attribute. This attribute assigns an “importance” value to a view in terms of how much space it should occupy on the screen. A larger weight value allows it to expand to fill any remaining space in the parent view.