How to resize Image with SwiftUI?

Question

You should use .resizable() before applying any size modifications on an Image.

Image(room.thumbnailImage)
    .resizable()
    .frame(width: 32.0, height: 32.0)

How about this:

struct ResizedImage: View {
    var body: some View {
        Image("myImage")
            .resizable()
            .scaledToFit()
            .frame(width: 200, height: 200)
    }
}

The image view is 200x200, but the image maintains the original aspect ratio (rescaling within that frame).

In SwiftUI, use the .resizable() method to resize an image. By using .aspectRatio() and specifying a ContentMode, you can either "Fit" or "Fill" the image, as appropriate.

For example, here is code that resizes the image by fitting:

Image("example-image")
.resizable()
.aspectRatio(contentMode: .fit)

Expanding on @rraphael's answer and comments:

As of Xcode 11 beta 2, you can scale an image to arbitrary dimensions, while maintaining the original aspect ratio by wrapping the image in another element.

e.g.

struct FittedImage: View
{
    let imageName: String
    let width: CGFloat
    let height: CGFloat

    var body: some View {
        VStack {
            Image(systemName: imageName)
                .resizable()
                .aspectRatio(1, contentMode: .fit)
        }
        .frame(width: width, height: height)
    }
}


struct FittedImagesView: View
{
    private let _name = "checkmark"

    var body: some View {

        VStack {

            FittedImage(imageName: _name, width: 50, height: 50)
            .background(Color.yellow)

            FittedImage(imageName: _name, width: 100, height: 50)
            .background(Color.yellow)

            FittedImage(imageName: _name, width: 50, height: 100)
            .background(Color.yellow)

            FittedImage(imageName: _name, width: 100, height: 100)
            .background(Color.yellow)

        }
    }
}

Results

(For some reason, the image is showing as a bit blurry. Rest assured that the real output is sharp.)

struct AvatarImage: View {
    var body: some View {

            Image("myImage")
                .resizable()
                .scaledToFill() // <=== Saves aspect ratio
                .frame(width: 60.0, height:60)
                .clipShape(Circle())

    }
}

To render the image with a fit aspect ratio and clipping to bounds, use this code:

struct ContentView: View {
    var body: some View {
        Image("donuts")
            .resizable()
            .scaledToFill()
            .frame(width: 200, height: 200)
            .border(Color.pink)
            .clipped()
    }
}

The result: