SwiftUI 屏蔽圆角矩形内的矩形

Question

Hello there. I am wondering, in SwiftUI, how do you mask the contents of a rounded rectangle so that a child rectangle clips the corners.

In my example I have a white rounded rectangle and a pink rectangle on a zstack, I've tried to apply clipping, but the pink rectangle does not conform to the corners.

I've tried applying.mask to the white rectangle, but it gives different results to expectations (sometimes it doesn't show the pink rectangle).

I did find an example where you can set your own cornerRadius Round Specific Corners SwiftUI

But I was wondering if perhaps there was a way to mask the internals/body of the pink rectangle so that it conforms to the parent's rounded rectangle?

My code follows;

var body: some View {
        GeometryReader { geometry in

            Color.gray
                .edgesIgnoringSafeArea(.top)
                .overlay(

                    ZStack (alignment: .topLeading) {

                        RoundedRectangle(cornerRadius: 16,
                                         style: .continuous)
                            .foregroundColor(.white)
                            .shadow(radius: 10)
                             // Tried using .mask here 

                        Rectangle()
                            .fill(Color.pink)
                            .frame(minWidth: 0, maxWidth: .infinity, maxHeight: 150, alignment: .top)
                            .clipped()


                    }
                    .frame(width: 300, height: 450, alignment: .center)
            )

        }
        .edgesIgnoringSafeArea(.all)
    }

Edit: To clarify:

The pink rectangle should remain as a rectangle, but clip the top left and right to match the parent white rounded rectangle.

Answer 1

If I correctly understood your goal, here is a solution (tested with Xcode 11.4)

ZStack (alignment: .topLeading) {

    RoundedRectangle(cornerRadius: 16,
                     style: .continuous)
        .foregroundColor(.white)
        .shadow(radius: 10)
         // Tried using .mask here

    Rectangle()
        .fill(Color.pink)
        .frame(minWidth: 0, maxWidth: .infinity, maxHeight: 150, alignment: .top)
        .clipped()


}
.clipShape(RoundedRectangle(cornerRadius: 16))       // << here !!
.frame(width: 300, height: 450, alignment: .center)

Answer 2

@Asperi already posted a great answer, I have done this aswell with using mask modifier in SwiftUI . Furthermore you only have to set cornerRadius once.

VStack(spacing: 0)
{
    ZStack(alignment: .center)
    {
       Rectangle()
       .fill(Color.red)
       .frame(width: 66, height: 20)

    }


    ZStack(alignment: .center)
    {
       Rectangle()
       .fill(Color.white)
       .frame(width: 66, height: 46)

    }
}
.mask(Rectangle()
        .cornerRadius(3.0)
        .frame(width: 66, height: 66)
)

Answer 3

check this out

struct ContentView: View {
    var body: some View {
        GeometryReader { geometry in

            Color.gray
                .edgesIgnoringSafeArea(.top)
                .overlay(

                    ZStack (alignment: .topLeading) {

                        RoundedRectangle(cornerRadius: 16,
                                         style: .continuous)
                            .foregroundColor(.white)
                            .shadow(radius: 10)
                        // Tried using .mask here

                        Rectangle()
                            .fill(Color.pink)
                            .frame(minWidth: 0, maxWidth: .infinity, maxHeight: 150, alignment: .top)
                            .clipShape(RoundedRectangle(cornerRadius: 16)) // <<<<<<


                    }
                    .frame(width: 300, height: 450, alignment: .center)
            )

        }
        .edgesIgnoringSafeArea(.all)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

Answer 4

I think the easier way is to apply cornerradius to ZStack

ZStack (alignment: .topLeading) {

    RoundedRectangle(cornerRadius: 16,
                 style: .continuous)
        .foregroundColor(.white)
        .shadow(radius: 10)
         // Tried using .mask here

    Rectangle()
       .fill(Color.pink)
       .frame(minWidth: 0, maxWidth: .infinity, maxHeight: 150, alignment: .top)
        //.clipped() //<<= here
}
.frame(width: 300, height: 450, alignment: .center)
.cornerRadius(20) //<<= here