Views are the fundamental building blocks of your app's user interface, and the UIView class defines the behaviors that are common to all views. A view object renders content within its bounds rectangle and handles any interactions with that content. The UIView class is a concrete class that you can instantiate and use to display a fixed background color.
You can also subclass it to draw more sophisticated content. To display labels, images, buttons, and other interface elements commonly found in apps, use the view subclasses provided by the UIKit framework rather than trying to define your own.
Because view objects are the main way your application interacts with the user, they have a number of responsibilities. Here are just a few:. Use Auto Layout to define the rules for resizing and repositioning your views in response to changes in the view hierarchy. A view is a subclass of UIResponder and can respond to touches and other types of events. Views can be nested inside other views to create view hierarchies, which offer a convenient way to organize related content.
Nesting a view creates a parent-child relationship between the child view being nested known as the subview and the parent known as the superview. A parent view may contain any number of subviews but each subview has only one superview.
Use the clips To Bounds property to change that behavior. The geometry of each view is defined by its frame and bounds properties. The frame property defines the origin and dimensions of the view in the coordinate system of its superview. The bounds property defines the internal dimensions of the view as it sees them and is used almost exclusively in custom drawing code. The center property provides a convenient way to reposition a view without changing its frame or bounds properties directly.
Normally, you create views in your storyboards by dragging them from the library to your canvas. You can also create views programmatically. When creating a view, you typically specify its initial size and position relative to its future superview. For example, the following example creates a view and places its top-left corner at the point 10, 10 in the superview's coordinate system once it is added to that superview.
You may add any number of subviews to a view, and sibling views may overlap each other without any issues in iOS. You can also exchange the position of already added subviews using the exchange Subview at: with Subview At: method.
After creating a view, create Auto Layout rules to govern how the size and position of the view change in response to changes in the rest of the view hierarchy. For more information, see Auto Layout Guide. View drawing occurs on an as-needed basis. When a view is first shown, or when all or part of it becomes visible due to layout changes, the system asks the view to draw its contents. When the actual content of your view changes, it is your responsibility to notify the system that your view needs to be redrawn.
These methods let the system know that it should update the view during the next drawing cycle. Because it waits until the next drawing cycle to update the view, you can call these methods on multiple views to update them at the same time. For detailed information about the view drawing cycle and the role your views have in this cycle, see View Programming Guide for iOS.
Changes to several view properties can be animated—that is, changing the property creates an animation starting at the current value and ending at the new value that you specify. The following properties of the UIView class are animatable:. To animate your changes, create a UIView Property Animator object and use its handler block to change the values of your view's properties.
The UIView Property Animator class lets you specify the duration and timing of your animations, but it performs the actual animations.
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The custom view's background colour for each cell in my tableView always uses the initial colour set when declaring my statusColour variable, and the colour set dynamically in cellForRowAt IndexPath is always ignored. This is my UIView subclass:. The problem is definitely coming from the UIView subclass. According some prior research, it looks like the overridden draw function could be causing the issue. Add slantedView in awakeFromNib method instead of init and also use property observers to change the backgroung color of slantedView as shown below:.
Learn more. Asked yesterday. Active yesterday. Viewed 36 times. Problem: The custom view's background colour for each cell in my tableView always uses the initial colour set when declaring my statusColour variable, and the colour set dynamically in cellForRowAt IndexPath is always ignored.
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CellStyle, reuseIdentifier: String? CustomTableViewCell cell. I followed the advice given in some other Stack Overflow questions by adding these lines: self.
Thanks in advance. LondonGuy LondonGuy 8, 9 9 gold badges 63 63 silver badges bronze badges. NicolasElPapu I added it. Sorry, I didn't include all of the code to keep the question short. However, I have added the statusContainer to my cell in my code.
I have looked around and because Swift is only about a week old, I cannot find an answer. The simplest way to add backgroundColor programmatically by using ColorLiteral. You need to add the property ColorLiteralXcode will prompt you with a whole list of colors in which you can choose any color.
You will also get the recently used colors from the storyboard. The response by Miknash and wolfgang gutierrez barrera was helpful to me. Only difference was I had to add rgbValue: to the function call. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. Asked 5 years, 10 months ago. Active 1 year, 1 month ago. Viewed k times. Is there a way to set the UIView background color with Swift? Does anyone have any suggestions? AstroCB Z-Tech Z-Tech 3, 4 4 gold badges 12 12 silver badges 10 10 bronze badges.
You are making excuses. You will jump right into the "header" where you'll find all the available functions. Active Oldest Votes. Jiaaro Jiaaro In swift self. Try This, It worked like a charm! Follow steps1 Add below line of code in viewDidLoadself. Hope this will help some one to set backgroundColor in different ways. Jaywant Khedkar Jaywant Khedkar 4, 27 27 silver badges 46 46 bronze badges. I love this tip. I was a little confused by the first step using "ColorLiteral" until finding "Color Literal" in auto completion.
I see that this question is solved, but, I want to add some information than can help someone.
Miknash 7, 3 3 gold badges 26 26 silver badges 43 43 bronze badges. WTF Mono. WTF 1, 2 2 gold badges 15 15 silver badges 23 23 bronze badges. You can use this extension as an alternative if you're dealing with RGB value. Turtle Turtle 71 1 1 silver badge 5 5 bronze badges.In this article we are going to see what a UIView can do and how you can use it to make your apps. The UIView class defines a rectangular area on the screen on which it shows content.
It handles the rendering of any content in its area and also any interactions with that content — touches and gestures.
Download this starter project and open it on the Main. You should see a red square. Starter Project. Now let see what actually happened when we changed the view. The first thing we did was to make the view taller and then move it around. Views draw content in a rectangular area.
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The size and position of that area are stored in the frame property. The frame has an origin — the position of the top left corner — and a size — the width and height of the view. You can find the frame by opening the Size Inspector. Make sure your Utilities Pane is visible. After that we changed the color to orange. This actually sets the backgroundColor property of the view to UIColor.
To understand how a frame represents a rectangle on the screen we have to take a look at the coordinate system used by views. The red square has the origin in x:y: and the size width:height: The top left corner of the screen is the point is 0, 0 or CGPointZero.
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The horizontal axis is the X axis and the vertical one is the Y axis. The more to the right a point is the greater the x coordinate will be. The lower a point is on the screen the greater the y coordinate will be.
The red square has a width of points. Can you guess the coordinates of points ABC from the image above? The object library contains all the types of objects that you can use to make the interface of your app.
Here are a few:.For debugging, I have set the UIView in the nib to red. The point of the UIView is to do various clipping and masking effects, so in the end I want the background to be clear. Clear within Draw rectthe background remains red. Clear, but the getter never gets hit and the view remains red. What basic concept am I overlooking?
For a sanity check, all of my other views behaviors are working correctly, and the Draw rect code is getting hit. I attached the simplest of examples. If I set this view to a custom class for a UIView in a nib with the background defined as red, the ClipView code does not successfully set the color to clear.
Or LayoutSubviews not really what its ment for, but it gets called predictably. BUT, it only added to my insanity. Clear, the debugger shows the background color to already be clear set in my original Draw rect method.
Butit will only achieve the desired effect of being clear if I set it again in LayoutSubviews. It almost seems as if the. NET property at least, the getter doesn't reflect the value actually getting sucked up by the view at runtime.
I've also read and tried a few things from blogs, but nothing seems to accomplish what I am looking for. I add this UIView to my cell's selectedBackgroundView and this works fine, my cell changes to the desired color on user selection.
I Accepted CodaFis answer because he added a comment which pointed to a pretty nice yet lengthy solution. I had to do quite a bit of revamping, but in the end, I now have the selectedBackgroundView's I needed which round the corners on the 1st and last cells, thanks again! Here is a n example of how I achieved this. This is how I've been doing it:.
In your case, the exact color of your selected cell thanks to the handy dandy Digital Color Meter would be. I know there is no way to round just the top-left and top-right corners only. I want to do this strictly by code, without images. Basically I want to add two UIButton, one on top and other just below it. Both having height half of cell. It needs to be similar to how the web handles visibility.
Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. The problem whith setting view. This apparently doesn't work. Now I've tried even these:. I don't get it what I do wrong because I only set the colors alpha to 0. Any ideas? You can set background color of view to the UIColor with alpha, and not affect view.
Setting alpha property of a view affects its subviews. If you want just transparent background set view's backgroundColor proprty to a color that has alpha component smaller than 1.
The problem you have found is that view is different from your UIView. For example your home screen is a view. You can accomplish this by going to your storyboard, clicking on the item, Identity Inspector, and changing the Restoration ID.
How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. Asked 5 years, 3 months ago. Active 2 years, 10 months ago. Viewed k times. Does anyone have any clue of how to solve this?