SwiftUI：属性包装器@FocusState的使用示例

@FocusState 用于管理视图中的焦点状态，通常与表单和文本输入相关联。

struct FocusExampleView: View {
    @State private var name = ""
    @FocusState private var isNameFieldFocused: Bool

    var body: some View {
        TextField("Name", text: $name)
            .focused($isNameFieldFocused)
        
        Button("Submit") {
            isNameFieldFocused = false
        }
    }
}