问题描述
我目前有一个 LazyVGrid
设置:
struct NetworkGrid: View {
var networks: [Network]
let columns = [
GridItem(.flexible()),GridItem(.flexible()),GridItem(.flexible())
]
var body: some View {
ScrollView {
LazyVGrid(columns: columns) {
ForEach(networks) { network in
NetworkCard(network: network)
}
}
}
}
}
我想根据当前窗口大小设置网格列数,即
func windowDidResize(_ notification: Notification) {
itemWidth = CGFloat(300)
if window.width <= itemWidth {
GridItem(.flexible()),GridItem(.flexible())
} else if window.width <= itemWidth * 2 {
GridItem(.flexible()),GridItem(.flexible())
} else if window.width <= itemWidth * 3 {
GridItem(.flexible()),GridItem(.flexible())
}
...
}
我将如何使用 SwiftUI 实现这样的观察者?
解决方法
SwiftUI 相当于监听窗口大小可能会使用 GeometryReader
。在您的示例中,您可以读取大小并根据其宽度读取动态决定列:
struct NetworkGrid: View {
var networks: [Network]
func columnsForWidth(width: CGFloat) -> [GridItem] {
print("Columns for width: \(width)")
return Array(repeating: GridItem(.flexible()),count: Int(width) / 100)
}
var body: some View {
GeometryReader { geometry in
ScrollView {
LazyVGrid(columns: columnsForWidth(width: geometry.size.width)) {
ForEach(networks) { network in
NetworkCard(network: network)
}
}
}
}
}
}