Path can not showing on map

I trying to add the location of schedule as mapmarks on map of MapKit, and connect them order by time. But the Path didn't show up, and I sure that the start and end are at the right position. So I wonder is the Path not allowed to overight the MapView? If so. How do I implement this?

ZStack{
                    Map(coordinateRegion: $region, annotationItems: markList) { location in
                        MapMarker(coordinate: CLLocationCoordinate2D(latitude: location.latitude, longitude: location.longitude), tint: .red)
                    }
                    .frame(height: proxyHight * 0.35)
                    .padding([.leading, .trailing], 22)
                    .cornerRadius(20)
                    .shadow( radius: 3, x: 3, y: 3)
                    
                    Path { path in
                            // Draw dotted lines between markers
                            for (index, location) in markList.enumerated() {
                                if index < markList.count - 1 {
                                    let nextLocation = markList[index + 1].coordinate
                                    let start = CGPoint(x: location.coordinate.longitude, y: location.coordinate.latitude)
                                    let end = CGPoint(x: nextLocation.longitude, y: nextLocation.latitude)
                                    //print("Drawing line from \(start) to \(end)")
                                    path.move(to: start)
                                    path.addLine(to: end)
                                }
                            }
                        }
                        .stroke(style: StrokeStyle(lineWidth: 2, dash: [5]))
                        .foregroundColor(Color.blue)
                    
                  
                    }

The CGPoints you pass to Path represents points in view space, not coordinates on earth. (0, 0) would be the point on the top left of the screen, not somewhere in the ocean near Africa.

Before iOS 17, SwiftUI's Map had very limited functionality, and this was very difficult to draw lines accurately on the map. I would suggest wrapping a MKMapView with a UIViewRepresentable. This gist shows a simple example.

In iOS 17+, you should use MapPolyline, which draws a path on the map.

Assuming markList.map(\.coordinate) is a [CLLocationCoordinate2D], you can write:

Map(initialPosition: .region(region)) {
    ForEach(markList) { mark in
        Marker("", coordinate: mark.coordinate)
    }
    MapPolyline(coordinates: markList.map(\.coordinate))
        .stroke(.blue, style: StrokeStyle(lineWidth: 2, dash: [5]))
}

Note that if you need to track the map region, you should use onMapCameraChange:

.onMapCameraChange(frequency: .continuous) {
    // do something with $0.region
}