Question

当前，我已经在SwiftUI中创建了一个自定义视图，其中包含带有一些详细信息的Image。我们如何在视图实例之外添加特定的图像修改器？

import Foundation
import SwiftUI
import Combine

struct RemoteImage: View {

    // Hold reference to our remote resource through binding
    @ObjectBinding
    private var resource: RemoteResource

    // Initialize the Image with a string
    init(urlString: String) {

        // Create our resource and request our data
        // Will fetch the resource from the internet
        self.resource = RemoteResource(urlString)
    }

    // Computed var that will return a placeholder image our our actual resource
    private var image: UIImage {
        self.resource.data.flatMap(UIImage.init) ?? UIImage(named: "placeholder")!
    }

    var body: some View {
        Image(uiImage: image)
    }
}

如何将RemoteImage的实例中的修饰符添加到Image

RemoteImage(urlString: "image-url-here")
    .resizable()
    .scaledToFit()

如果有人会想解决我的问题，请告诉我。

Answer 1

如果您这样声明RemoteImage：

import Foundation
import SwiftUI
import Combine

struct RemoteImage: View {

    // Hold reference to our remote resource through binding
    @ObservedObject
    private var resource: RemoteResource

    // Initialize the Image with a string
    init(urlString: String) {

        // Create our resource and request our data
        // Will fetch the resource from the internet
        self.resource = RemoteResource(urlString)
    }

    // Computed var that will return a placeholder image our our actual resource
    private var image: UIImage {
        self.resource.data.flatMap(UIImage.init) ?? UIImage(named: "placeholder")!
    }

    var body: Image {
        Image(uiImage: image)
    }
}

然后您可以像这样调用所有特定于图像的修饰符：

RemoteImage(urlString: "image-url-here").body
    .resizable()
    .scaledToFit()

不太理想，但是至少您不必手动重新声明每个修饰符。

Answer 2

下面的代码添加了两个属性，您将可以调用

RemoteImage(urlString: myLink).resizable().renderingMode(myRenderingMode)

您可以添加所需的任何数量。

struct RemoteImage: View {   
    // Hold reference to our remote resource through binding
    @ObjectBinding
    private var resource: RemoteResource

    // Initialize the Image with a string
    init(urlString: String) {

        // Create our resource and request our data
        // Will fetch the resource from the internet
        self.resource = RemoteResource(urlString)
    }

    // Computed var that will return a placeholder image our our actual resource
    private var image: UIImage {
        self.resource.data.flatMap(UIImage.init) ?? UIImage(named: "placeholder")!
    }

    // Put whatever new properties you want here *****************
    private var _resizable: (capInsets: EdgeInsets, resizingMode: Image.ResizingMode) = (EdgeInsets(), .stretch)
    private var _renderingMode: Image.TemplateRenderingMode? = nil
    // *****************

    var body: some View {
        Image(uiImage: image)
           .resizable(capInsets: _resizable.capInsets, resizingMode: _resizable.resizingMode)
           .renderingMode(_renderingMode)
    }

    // Put whatever new functions you want here *****************
    func resizable(capInsets: EdgeInsets = EdgeInsets(), resizingMode: Image.ResizingMode = .stretch) -> RemoteImageComponent {
        var rm = self
        rm._resizable = (capInsets, resizingMode)
        return rm
    }

    func renderingMode(_ renderingMode: Image.TemplateRenderingMode?) -> RemoteImageComponent {
        var rm = self
        rm._renderingMode = renderingMode
        return rm
    }
}

如果您需要知道要添加到新属性中的参数，则只需单击CMD，然后单击系统功能以查看需要什么。

在SwiftUI的自定义视图中访问Image的修饰符

2 个答案: