Add a border with cornerRadius to an Image in SwiftUI Xcode beta 5

问题

how can I add a border with a cornerRadius to an Image. I get a deprecation warning saying that i should use a RoundedRectange Shape, but i don't know how to use that exactly

Beta 4:

Image(uiImage: ...)
   .border(Color.black, width: 2, cornerRadius: 10)

回答1:

SwiftUI 1.0

Using cornerRadius & overlay Modifiers

Here is another way in which we can use a cornerRadius modifier (which clips the view) and then overlay a stroke with a color.

VStack(spacing: 40) {
    Text("Image Border").font(.largeTitle)
    Text("Using cornerRadius & overlay").font(.title).foregroundColor(.gray)
    Text("Using cornerRadius will also clip the image. Then overlay a border.")
        .frame(minWidth: 0, maxWidth: .infinity)
        .font(.title)
        .padding()
        .background(Color.orange)
        .foregroundColor(.black)

    Image("profile")
        .cornerRadius(10)
        .overlay(RoundedRectangle(cornerRadius: 10)
            .stroke(Color.orange, lineWidth: 4))
        .shadow(radius: 10)
}

Result

回答2:

Consider this: adding a modifier to a view will return a new View instance that wraps the previous instance. This is also why the order in which you add modifiers matters.

We can use this to our advantage: by adding a padding, then adding a background to our new View, we can create our own additional layers:

Image("cat")
    .cornerRadius(7) // Inner corner radius
    .padding(5) // Width of the border
    .background(Color.primary) // Color of the border
    .cornerRadius(10) // Outer corner radius

Results in:

You can even turn this in a ViewModifier to be reusable more easily:

struct RoundedEdge: ViewModifier {
    let width: CGFloat
    let color: Color
    let cornerRadius: CGFloat

    func body(content: Content) -> some View {
        content.cornerRadius(cornerRadius - width)
            .padding(width)
            .background(color)
            .cornerRadius(cornerRadius)
    }
}

Using it would become:

Image("cat").modifier(RoundedEdge(width: 5, color: .black, cornerRadius: 20))

This workd for any SwiftUI View, like Text:

Text("Some text")
    .padding(15)
    .background(Color.red)
    .modifier(RoundedEdge(width: 5, color: .black, cornerRadius: 20))

Results in:

回答3:

First, note that the way you were doing it, was not clipping the image. Maybe you did not noticed if the image was too small, or if it had a background of the same color of your canvas. But even while using your beta 4 syntax, you needed to add .clipShape().

---

Back to your question, according to Beta 5 release notes:

Complex overloads for the background(:alignment:) and border(:width:) modifiers are deprecated. Use shapes in a background(:alignment:) or overlay(:alignment:) to draw these instead. (53067530)

So the pattern would be something like this:

.overlay(RoundedRectangle(...).stroke(...).foregroundColor(...))

In your specific case:

Image("mypic").resizable().frame(width: 300, height: 300)
    .clipShape(RoundedRectangle(cornerRadius: 30))
    .overlay(RoundedRectangle(cornerRadius: 30).stroke(lineWidth: 2).foregroundColor(Color.black))

回答4:

Write a rounded text view which is same with Image View

struct RoundedTextView: View {
    var body: some View {
        Text("Rounded Text View")
            .frame(width: 200, height: 200, alignment: .center)
            .foregroundColor(.white)
            .background(Color.blue)
            .cornerRadius(16)
            .overlay(
                RoundedRectangle(cornerRadius: 16).stroke(Color.yellow, lineWidth: 8)
            )
    }
}

Preview like this image:

回答5:

I really liked kontiki's answer but not the length so I wrote:

import SwiftUI

func strokedRoundedRectangle(
        cornerRadius r: CGFloat,
        lineWidth w: CGFloat = 1,
        color c: Color = .primary
    ) -> some View {

    return RoundedRectangle(cornerRadius: r).stroke(lineWidth: w).foregroundColor(c)
}

来源：https://stackoverflow.com/questions/57269651/add-a-border-with-cornerradius-to-an-image-in-swiftui-xcode-beta-5