SwiftUIでアラートとシートを出し分ける
SwiftUIでアラートとシートを出し分ける方法です。 TextField に入力された文字列が Double に変換できるかチェックします。 もし Double に変換できるのであればシートを表示し、もし Double に変換できないのであればアラートを表示します。
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| import SwiftUI | |
| struct ContentView: View { | |
| @State var numberString: String = "" | |
| @State var showingAlert: Bool = false | |
| @State var showingSheet: Bool = false | |
| var body: some View { | |
| VStack { | |
| TextField("Input Number", text: $numberString) | |
| .padding() | |
| .textFieldStyle(RoundedBorderTextFieldStyle()) | |
| Button(action: { | |
| // Can numberString convert to Double? | |
| guard Double(self.numberString) != nil else { | |
| self.showingAlert = true | |
| return | |
| } | |
| self.showingSheet = true | |
| }) { | |
| Text("Show Sheet") | |
| } | |
| } | |
| .alert(isPresented: $showingAlert) { | |
| Alert(title: Text("Error"), message: Text("Please Input Number"), dismissButton: .default(Text("Close"))) | |
| } | |
| .sheet(isPresented: $showingSheet) { | |
| Text("\(self.numberString) can convert to Double") | |
| } | |
| } | |
| } | |
| struct ContentView_Previews: PreviewProvider { | |
| static var previews: some View { | |
| ContentView() | |
| } | |
| } |