在SwiftUI中使用获取视图的宽度 [英] Get width of a view using in SwiftUI

问题描述

我需要在SwiftUI中获取渲染视图的宽度，这显然不那么容易.

I need to get width of a rendered view in SwiftUI, which is apparently not that easy.

我的看法是，我需要一个函数来返回视图的尺寸，就像这样简单.

The way I see it is that I need a function that returns a view's dimensions, simple as that.

var body: some View {
    VStack(alignment: .leading) {
        Text(timer.name)
            .font(.largeTitle)
            .fontWeight(.heavy)
        Text(timer.time)
            .font(.largeTitle)
            .fontWeight(.heavy)
            .opacity(0.5)
    }
}

推荐答案

获取View尺寸的唯一方法是使用GeometryReader.读者将返回容器的尺寸.

The only way to get the dimensions of a View is by using a GeometryReader. The reader return the dimensions of the container.

什么是几何读取器?该文档说:

What is a geometry reader? the documentation says:

根据其自身大小和坐标空间定义其内容的容器视图. Apple Doc

因此您可以通过执行以下操作获取尺寸:

So you could get the dimensions by doing this:

struct ContentView: View {

   @State var frame: CGSize = .zero

    var body: some View {
        HStack {
            GeometryReader { (geometry) in
                self.makeView(geometry)
            }
        }

    }

    func makeView(_ geometry: GeometryProxy) -> some View {
        print(geometry.size.width, geometry.size.height)

        DispatchQueue.main.async { self.frame = geometry.size }

        return Text("Test")
                .frame(width: geometry.size.width)
    }
}

打印尺寸是HStack的尺寸，它是内部视图的容器.

The printed size is the dimension of the HStack that is the container of inner view.

您可能会使用另一个GeometryReader来获取内部尺寸.

You could potentially using another GeometryReader to get the inner dimension.

但是请记住，SwiftUI是一个声明性框架.因此，您应该避免计算视图的尺寸:

But remember, SwiftUI is a declarative framework. So you should avoid calculating dimensions for the view:

阅读更多示例:

• 使VStack填充宽度SwiftUI中的屏幕
• 如何制作在SwiftUI中查看另一个视图的大小

• Make a VStack fill the width of the screen in SwiftUI
• How to make view the size of another view in SwiftUI

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