SwiftUI @Binding Initialize
- If you need a simple property that belongs to a single view you should use @State
- If you need to have complex property that may belong to several view(like 2-3 views) you shall use @ObjectBinding
- Lastly, if you need to have property that needs to use all around views you shall use @EnvironmentObject. Source for detail information
For your case, if you still would like to initialize your Binding variable you can use:
var binding: Binding = .constant(false)
Using Binding.constant(false)
is fine but only for static previews. If you actually wanna launch a Live Preview, constant
will not behave the same way as the real case as it will never be updated by your actions. I personally use Live Preview a lot, as I can play around with an isolated view.
Here is what I do for previews requiring Binding
:
import SwiftUI
struct SomeView: View {
@Binding var code: String
var body: some View {
// some views modifying code binding
}
}
struct SomeView_Previews: PreviewProvider {
static var previews: some View {
PreviewWrapper()
}
struct PreviewWrapper: View {
@State(initialValue: "") var code: String
var body: some View {
SomeView(code: $code)
}
}
}
When you use your LoggedInView
in your app you do need to provide some binding, such as an @State
from a previous view or an @EnvironmentObject
.
For the special case of the PreviewProvider
where you just need a fixed value you can use .constant(false)
E.g.
#if DEBUG
struct LoggedInView_Previews : PreviewProvider {
static var previews: some View {
LoggedInView(dismissView: .constant(false))
}
}
#endif