如果值等于SwiftUI中的"0“，则显示占位符

@State private var value = "0"

if value == "0" {
    Text("占位符")
} else {
    // 显示其他内容
}

import SwiftUI

struct ContentView: View {
    @State private var value = "0"
    
    var body: some View {
        VStack {
            TextField("输入值", text: $value)
                .textFieldStyle(RoundedBorderTextFieldStyle())
                .padding()
            
            if value == "0" {
                Text("占位符")
                    .foregroundColor(.gray)
            } else {
                Text("值不为0")
                    .foregroundColor(.blue)
            }
        }
    }
}

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