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Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Its generally a bad idea to call addView inside onLayout because addView internally triggers a requestLayout which eventually will call onLayout.

So you end up triggering a layout while you are in the middle of a layout. It basically doesn't trigger a layout pass doesn't call requestLayout internally. Adds a view during layout. This is useful if in your onLayout method, you need to add more views as does the list view for example.

If index is negative, it means put it at the end of the list. For more see this. Learn more. Asked 6 years, 11 months ago. Active 5 years, 3 months ago. Viewed 6k times.

android view addview

I have seen some widgets using addView and sometimes addViewInLayout. What is the difference between them? What will happen if I replace one with the other? BR, Henry ps. Henry Henry 1 1 gold badge 8 8 silver badges 18 18 bronze badges. Active Oldest Votes.

Crisoforo Gaspar 3, 1 1 gold badge 16 16 silver badges 26 26 bronze badges. Arun C Arun C 8, 1 1 gold badge 23 23 silver badges 41 41 bronze badges. That is what i explained addView can be called in any viewgroup object AND addViewInLayout must be called form onLayout method when you are create a custom view group.

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Android addview—动态添加view

Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Programming tutorials can be a real drag. Featured on Meta.All the interaction of a user with the Android application is through the user interface UIhence it is very important to understand the basics about the User Interface of an android application.

Here in this tutorial, we are going to cover about various Views and ViewGroups and will try to explain how they can be used to design the User Interface of an android application. View is the basic building block of UI User Interface in android. View refers to the android. View class extends Object class and implements Drawable.

CallbackKeyEvent. Callback and AccessibilityEventSource. View can be considered as a rectangle on the screen that shows some type of content. It can be an image, a piece of text, a button or anything that an android application can display. The rectangle here is actually invisible, but every view occupies a rectangle shape. The answer is either we can set it manually, by specifying the exact size with proper units or by using some predefined values.

A View is also known as Widget in Android. Any visual that we can see on screen and interactive with which user can interact with is called a Widget. Now, as we have explained earlier as well, to draw anything in your android application, you will have to sepcify it in the design XML files. And to add functionality we will create Java files. So, every View subclass needs to follow this format so that it can appear on the screen of the app. And this format is nothing but default XML style.

There are two attributes that are necessary for every View. These attributes define the size of the invisible rectangle that a view makes. Using these attributes we can easily control the size for every view in our android application.Jakob Jenkov Last update: An Android app contains one or more activities.

An Android activity is a screen, similar to windows in a desktop application. Inside an activity you can have GUI components. It may sound a bit abstract at this point, but I will explain both in more detail below.

For instance, the TextView class which is used to display text labels in Android apps is a subclass of View. Android contains the following commonly used View subclasses:. The ViewGroup class is a subclass of the View class.

ViewGroup instances work as containers for View instances to group View instances together. Android contains the following commonly used ViewGroup subclasses:.

android view addview

These are not the only ViewGroup subclasses Android contains. There are others but which are less used. The ViewGroup subclasses listed above group View instances together and takes care of their layout. For instance, the LinearLayout will render the components after each other either horizontally or vertically. Android Development. Tweet Jakob Jenkov. Right 1 Right 2.

View Binding

All Trails. Trail TOC. Page TOC.The View to display banner ads. Home Guides Reference Downloads. Package Summary ads. Inter-operational packages. The ad size and ad unit ID must be set before calling loadAd. From class android. LayoutParams arg1.

android view addview

LayoutParams arg2. LayoutParams arg2, boolean arg3. LayoutParams arg1, int arg2, int arg3. LayoutParams arg0. AnimationListener arg0. OnHierarchyChangeListener arg0. Callback arg1, int arg2. Callback arg1. OnAttachStateChangeListener arg0.

android view addview

OnLayoutChangeListener arg0. OnUnhandledKeyEventListener arg0. AccessibilityDelegate arg0. Mode arg0. OnApplyWindowInsetsListener arg0. OnCapturedPointerListener arg0. OnClickListener arg0. OnContextClickListener arg0. OnCreateContextMenuListener arg0. OnDragListener arg0.

OnFocusChangeListener arg0. OnGenericMotionListener arg0. OnHoverListener arg0. OnKeyListener arg0. OnLongClickListener arg0. OnScrollChangeListener arg0. OnTouchListener arg0. Callback arg0, int arg1. Callback arg0. DragShadowBuilder arg1, Object arg2, int arg3. DragShadowBuilder arg0. From class java. Object clone. From interface android.A FrameLayout with a rounded corner background and shadow. CardView uses elevation property on Lollipop for shadows and falls back to a custom emulated shadow implementation on older platforms.

Due to expensive nature of rounded corner clipping, on platforms before Lollipop, CardView does not clip its children that intersect with rounded corners. Instead, it adds padding to avoid such intersection See setPreventCornerOverlap boolean to change this behavior. Before Lollipop, CardView adds padding to its content and draws shadows to that area. Since padding is used to offset content for shadows, you cannot set padding on CardView.

Instead, you can use content padding attributes in XML or setContentPadding int, int, int, int in code to set the padding between the edges of the CardView and children of CardView.

Note that, if you specify exact dimensions for the CardView, because of the shadows, its content area will be different between platforms before Lollipop and after Lollipop. By using api version specific resource values, you can avoid these changes.

Alternatively, If you want CardView to add inner padding on platforms Lollipop and after as well, you can call setUseCompatPadding boolean and pass true. To change CardView's elevation in a backward compatible way, use setCardElevation float.

To avoid moving the View while shadow size is changing, shadow size is clamped by getMaxCardElevation. If you want to change elevation dynamically, you should call setMaxCardElevation float when CardView is initialized. Returns whether CardView should add extra padding to content to avoid overlaps with rounded corners on pre-Lollipop platforms. On pre-Lollipop platforms, CardView does not clip the bounds of the Card for the rounded corners. Sets the padding between the Card's edges and the children of CardView.

Depending on platform version or getUseCompatPadding settings, CardView may update these values before calling setPadding int, int, int, int. Updates the backward compatible maximum elevation of the CardView.

Instead, it adds padding to content so that it won't overlap with the rounded corners. You can disable this behavior by setting this field to false. Setting this value on Lollipop and above does not have any effect unless you have enabled compatibility padding. CardView adds additional padding to draw shadows on platforms before Lollipop. This may cause Cards to have different sizes between Lollipop and before Lollipop. If you need to align CardView with other Views, you may need api version specific dimension resources to account for the changes.

As an alternative, you can set this flag to true and CardView will add the same padding values on platforms Lollipop and after. Since setting this flag to true adds unnecessary gaps in the UI, default value is false. Content and code samples on this page are subject to the licenses described in the Content License. The second Android 11 Developer Preview is now available, test it out and share your feedback. Android Developers.View binding is a feature that allows you to more easily write code that interacts with views.

Once view binding is enabled in a module, it generates a binding class for each XML layout file present in that module. An instance of a binding class contains direct references to all views that have an ID in the corresponding layout. View binding is enabled on a module by module basis. To enable view binding in a module, add the viewBinding element to its build. If view binding is enabled for a module, a binding class is generated for each XML layout file that the module contains.

Each binding class contains references to the root view and all views that have an ID. The name of the binding class is generated by converting the name of the XML file to camel case and adding the word "Binding" to the end.

The generated binding class is called ResultProfileBinding. This class has two fields: a TextView called name and a Button called button.

The ImageView in the layout has no ID, so there is no reference to it in the binding class. Every binding class also includes a getRoot method, providing a direct reference for the root view of the corresponding layout file.

How to Dynamically Add Views into View in Android?

The following sections demonstrate the use of generated binding classes in activities and fragments. To set up an instance of the binding class for use with an activity, perform the following steps in the activity's onCreate method:. To set up an instance of the binding class for use with a fragment, perform the following steps in the fragment's onCreateView method:.

View binding has important advantages over using findViewById :. These differences mean that incompatibilities between your layout and your code will result in your build failing at compile time rather than at runtime. View binding and data binding both generate binding classes that you can use to reference views directly. However, view binding is intended to handle simpler use cases and provides the following benefits over data binding:. Because of these considerations, it is best in some cases to use both view binding and data binding in a project.

You can use data binding in layouts that require advanced features and use view binding in layouts that do not. Content and code samples on this page are subject to the licenses described in the Content License. App Basics. Build your first app. App resources. Resource types. App manifest file. App permissions. Device compatibility. Multiple APK support.The user interface in an android app is made with a collection of View and ViewGroup objects.

Generally, the android apps will contain one or more activities and each activity is a one screen of app. Generally, the android apps will contain one or more activities and each activity is a one screen of the app. The View is a base class for all UI components in android. For example, the EditText class is used to accept the input from users in android apps, which is a subclass of View. Following are the some of common View subclasses that will be used in android applications.

The ViewGroup is a subclass of View and it will act as a base class for layouts and layouts parameters. The ViewGroup will provide an invisible containers to hold other Views or ViewGroups and to define the layout properties.

Both View and ViewGroup subclasses together will play a key role to create a layouts in android applications. Android View and ViewGroup with Examples.

Android ViewGroup The ViewGroup is a subclass of View and it will act as a base class for layouts and layouts parameters. Following are the commonly used ViewGroup subclasses in android applications.

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