Image view (system and asset) in iOS Swift - Mini App: Build & Ship

Build: ImageViewScreen

This screen shows two images: one from the system icons and one from the app assets.

Target UI

-------------------------
|       ImageViewScreen  |
|-----------------------|
|  [System Icon Image]   |
|                       |
|  [Asset Image]         |
|                       |
|                       |
-------------------------

Display a system image using Image(systemName:).

Display an image from the app assets.

Center both images vertically with some spacing.

Set the system image tint color to blue.

Set the asset image content mode to aspect fit.

Use SwiftUI for the UI.

Starter Code

iOS Swift

import SwiftUI

struct ImageViewScreen: View {
    var body: some View {
        VStack {
            // TODO: Add system image here
            
            // TODO: Add asset image here
        }
        .padding()
    }
}

struct ImageViewScreen_Previews: PreviewProvider {
    static var previews: some View {
        ImageViewScreen()
    }
}

Task 1

Task 2

Solution

iOS Swift

import SwiftUI

struct ImageViewScreen: View {
    var body: some View {
        VStack(spacing: 40) {
            Image(systemName: "star.fill")
                .resizable()
                .scaledToFit()
                .frame(width: 100, height: 100)
                .foregroundColor(.blue)
            
            Image("exampleImage")
                .resizable()
                .scaledToFit()
                .frame(width: 150, height: 150)
        }
        .padding()
    }
}

struct ImageViewScreen_Previews: PreviewProvider {
    static var previews: some View {
        ImageViewScreen()
    }
}

We use a VStack to stack the two images vertically with spacing of 40 points for clear separation. The system image uses Image(systemName: "star.fill"), which is resizable and scaled to fit a 100x100 frame, and tinted blue with foregroundColor(.blue). The asset image named "exampleImage" is also resizable and scaled to fit a 150x150 frame to show the image properly without distortion. Padding is added around the VStack for spacing from screen edges.

Final Result

Completed Screen

-------------------------
|       ImageViewScreen  |
|-----------------------|
|        ★ (blue)        |
|                       |
|    [exampleImage]      |
|                       |
|                       |
-------------------------

The screen shows a blue star system icon on top.

Below it, the asset image named 'exampleImage' is displayed.

Both images scale nicely and keep their aspect ratio.

Stretch Goal

Add a toggle button to switch the system image tint color between blue and red.

💡 Hint

Use a @State variable to track the color and change foregroundColor dynamically when the button is tapped.

Practice

1. What is the correct way to create an image view that displays an image named "logo" from your app's assets?

easy

A. UIImageView(image: UIImage(named: "logo"))

B. UIImageView(image: UIImage(systemName: "logo"))

C. UIImageView(named: "logo")

D. UIImageView(systemName: "logo")

Solution

1. Step 1: Understand UIImageView initialization

   UIImageView is initialized with a UIImage object, not a string name directly.

2. Step 2: Load image from assets correctly

   Use UIImage(named:) to load an image from app assets by name.

3. Final Answer:

   UIImageView(image: UIImage(named: "logo")) -> Option A

4. Quick Check:

   Load asset image with UIImage(named:) = D [OK]

Hint: Use UIImage(named:) for asset images, not systemName [OK]

Common Mistakes:

• Using UIImage(systemName:) for asset images
• Passing string directly to UIImageView initializer
• Confusing UIImageView(named:) which doesn't exist

2. Which of the following is the correct syntax to create a system image view with the icon named "star.fill"?

easy

A. UIImageView(image: UIImage(named: "star.fill"))

B. UIImageView(systemName: "star.fill")

C. UIImageView(image: UIImage(systemName: "star.fill"))

D. UIImageView(image: "star.fill")

Solution

1. Step 1: Identify system image loading method

   System icons are loaded using UIImage(systemName:).

2. Step 2: Initialize UIImageView with system image

   Pass UIImage(systemName: "star.fill") to UIImageView's image parameter.

3. Final Answer:

   UIImageView(image: UIImage(systemName: "star.fill")) -> Option C

4. Quick Check:

   System image uses UIImage(systemName:) = B [OK]

Hint: Use UIImage(systemName:) for system icons only [OK]

Common Mistakes:

• Using UIImage(named:) for system icons
• Trying to initialize UIImageView with systemName directly
• Passing string instead of UIImage object

3. What will be the result of this Swift code snippet?

let imageView = UIImageView(image: UIImage(systemName: "heart.fill"))
imageView.tintColor = .red

medium

A. An image view showing a red filled heart system icon

B. An image view showing a heart icon with default color (black)

C. A runtime error because tintColor cannot be set

D. An empty image view with no image displayed

Solution

1. Step 1: Load system image "heart.fill"

   UIImage(systemName: "heart.fill") loads a filled heart icon.

2. Step 2: Set tintColor to red

   Setting imageView.tintColor to .red colors the system icon red.

3. Final Answer:

   An image view showing a red filled heart system icon -> Option A

4. Quick Check:

   System icon + tintColor = colored icon [OK]

Hint: System icons respect tintColor for color changes [OK]

Common Mistakes:

• Assuming system icons ignore tintColor
• Confusing asset images with system icons for tinting
• Expecting default black color after setting tintColor

4. Identify the error in this Swift code that tries to display a system image "bell" in an image view:

let imageView = UIImageView(image: UIImage(named: "bell"))
imageView.tintColor = .blue

medium

A. The code is correct and will display a blue bell icon

B. UIImageView does not have a tintColor property

C. The image name "bell" is invalid for assets

D. UIImage(named:) cannot load system images like "bell"

Solution

1. Step 1: Check image loading method

   UIImage(named:) loads images from app assets, not system icons.

2. Step 2: Recognize system image loading requirement

   System images like "bell" must be loaded with UIImage(systemName:).

3. Final Answer:

   UIImage(named:) cannot load system images like "bell" -> Option D

4. Quick Check:

   System images need UIImage(systemName:) = A [OK]

Hint: Use UIImage(systemName:) for system icons, not UIImage(named:) [OK]

Common Mistakes:

• Using UIImage(named:) for system icons
• Assuming tintColor works without correct image loading
• Thinking UIImageView lacks tintColor property

5. You want to display a system image "trash" in red color and an asset image "icon" in your app. Which code snippet correctly creates both UIImageViews with the right images and colors?

hard

A. let trashView = UIImageView(image: UIImage(systemName: "trash"))
trashView.tintColor = .red
let iconView = UIImageView(image: UIImage(systemName: "icon"))

B. let trashView = UIImageView(image: UIImage(systemName: "trash"))
trashView.tintColor = .red
let iconView = UIImageView(image: UIImage(named: "icon"))

C. let trashView = UIImageView(image: UIImage(named: "trash"))
trashView.tintColor = .red
let iconView = UIImageView(image: UIImage(systemName: "icon"))

D. let trashView = UIImageView(image: UIImage(named: "trash"))
trashView.tintColor = .red
let iconView = UIImageView(image: UIImage(named: "icon"))

Solution

1. Step 1: Load system image "trash" correctly

   Use UIImage(systemName: "trash") for system icon and set tintColor to red.

2. Step 2: Load asset image "icon" correctly

   Use UIImage(named: "icon") for asset image without tintColor.

3. Final Answer:

   let trashView = UIImageView(image: UIImage(systemName: "trash"))\ntrashView.tintColor = .red\nlet iconView = UIImageView(image: UIImage(named: "icon")) -> Option B

4. Quick Check:

   System image + tintColor, asset image with UIImage(named:) = C [OK]

Hint: System images use systemName + tintColor; assets use named without tint [OK]

Common Mistakes:

• Mixing UIImage(named:) and UIImage(systemName:) incorrectly
• Setting tintColor on asset images expecting color change
• Using systemName for asset images