【SwiftUI模块】0012、SwiftUI-搭建一个类似微博、网易云、抖音个人页面的头部下拉放大图片效果

SwiftUI模块系列 - 已更新11篇
SwiftUI项目 - 已更新1个项目
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技术:SwiftUI、SwiftUI3.0、下拉放大、tableview粘性头部、头部下拉放大图片、Spotify
运行环境:
SwiftUI3.0 + Xcode13.4.1 + MacOS12.5 + iPhone Simulator iPhone 13 Pro Max

概述

使用SwiftUI做一个一个类似微博、网易云、抖音个人页面的头部下拉放大图片 - 效果

详细

一、运行效果

二、项目结构图

三、程序实现 - 过程

思路:
1.创建头部模块 进行测试上下滚动拥有放大缩小效果
2.搭建分类模块 固定在头部下面
3.搭建列表模块
4.监听滚动偏移的操作

1.创建一个项目命名为 SpotifyResponvieUI

1.1.引入资源文件和颜色

颜色
BG #281A1A
Green #4DD037
随机图片9张
个人大图背景1张
logo1张

2. 创建一个虚拟文件New Group 命名为 View

3. 创建一个虚拟文件New Group 命名为 Model

4. 创建一个文件New File 选择SwiftUI View类型 命名为Album 并且继承Identifiable

5. 创建一个文件New File 选择SwiftUI View类型 命名为Home

主要是: 展示 个人页面下拉放大缩小图片效果

6. 创建一个文件New File 选择SwiftUI View类型 命名为OffsetModifier

Code

ContentView - 主窗口

主要是展示主窗口Home和设置暗黑模式

import SwiftUI

struct ContentView: View {
    var body: some View {
        Home()
        // 永远是黑暗模式
            .preferredColorScheme(.dark)
    }
    
}

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

Home - 主页

思路

1. 主要就是展示大图背景 + 固定的分类 + 列表模块

//
//  Home.swift
//  SpotifyResponvieUI (iOS)
//
//  Created by lyh on 2022/8/23.
//

import SwiftUI

struct Home: View {
    @State var currentType: String = "Popular"
    // 光滑滑动效果
    @Namespace var animation
    @State var _albums: [Album] = albums
    
    // x,y
    @State var headerOffsets: (CGFloat,CGFloat) = (0,0)
    
    var body: some View {
        ScrollView(.vertical, showsIndicators: false) {
            VStack(spacing: 0){
                HeaderView()
                // 带内容的固定标题
                LazyVStack(pinnedViews: [.sectionHeaders]) {
                    Section {
                        SongList()
                    } header: {
                        PinnedHeaderView()
                            .background(Color.black)
                            .offset(y: headerOffsets.1 > 0 ? 0 : -headerOffsets.1 / 8)
                            .modifier(OffsetModifier(offset: $headerOffsets.0, returnFromStart: false))
                            .modifier(OffsetModifier(offset: $headerOffsets.1))
                    }
                }
            }
        }
        .overlay(content: {
            Rectangle()
                .fill(.black)
                .frame(height: 50)
                .frame(maxHeight: .infinity,alignment: .top)
                .opacity(headerOffsets.0 < 5 ? 1 : 0)
        })
        .coordinateSpace(name: "SCROLL")
        .ignoresSafeArea(.container, edges: .vertical)
    }
    
    // 固定的内容
    @ViewBuilder
    func SongList()->some View{
        VStack(spacing: 25){
            ForEach($_albums){$album in
                
                HStack(spacing: 12){
                    
                    Text("#\(getIndex(album: album) + 1)")
                        .fontWeight(.semibold)
                        .foregroundColor(.gray)
                    
                    Image(album.albumImage)
                        .resizable()
                        .aspectRatio(contentMode: .fill)
                        .frame(width: 55, height: 55)
                        .clipShape(RoundedRectangle(cornerRadius: 10, style: .continuous))
                    
                    VStack(alignment: .leading, spacing: 8) {
                        Text(album.albumName)
                            .fontWeight(.semibold)
                        
                        Label {
                            Text("65,587,909")
                        } icon: {
                            Image(systemName: "beats.headphones")
                                .foregroundColor(.white)
                        }
                        .foregroundColor(.gray)
                        .font(.caption)
                    }
                    .frame(maxWidth: .infinity,alignment: .leading)
                    
                    Button {
                        album.isLiked.toggle()
                    } label: {
                     
                        Image(systemName: album.isLiked ? "suit.heart.fill" : "suit.heart")
                            .font(.title3)
                            .foregroundColor(album.isLiked ? Color("Green") : .white)
                    }
                    
                    Button {
                    } label: {
                     
                        Image(systemName: "ellipsis")
                            .font(.title3)
                            .foregroundColor(.white)
                    }
                }
            }
        }
        .padding()
        .padding(.top,25)
        .padding(.bottom,150)
    }
    
    func getIndex(album: Album)->Int{
        return _albums.firstIndex { currentAlbum in
            return album.id == currentAlbum.id
        } ?? 0
    }
    
    // 头部视图
    @ViewBuilder
    func HeaderView()->some View{
        GeometryReader{proxy in
            let minY = proxy.frame(in: .named("SCROLL")).minY
            let size = proxy.size
            let height = (size.height + minY)
            
            Image("Ariana")
                .resizable()
                .aspectRatio(contentMode: .fill)
                .frame(width: size.width,height: height > 0 ? height : 0,alignment: .top)
                .overlay(content: {
                    ZStack(alignment: .bottom) {
                        
                        // 调暗文本内容
                        LinearGradient(colors: [
                            .clear,
                            .black.opacity(0.8)
                        ], startPoint: .top, endPoint: .bottom)
                        
                        VStack(alignment: .leading, spacing: 12) {
                            
                            Text("宇夜iOS")
                                .font(.callout)
                                .foregroundColor(.gray)
                            
                            HStack(alignment: .bottom, spacing: 10) {
                                Text("Ariana Grande")
                                    .font(.title.bold())
                                
                                Image(systemName: "checkmark.seal.fill")
                                    .foregroundColor(.blue)
                                    .background{
                                        Circle()
                                            .fill(.white)
                                            .padding(3)
                                    }
                            }
                            
                            Label {
                             
                                Text("Monthly Listeners")
                                    .fontWeight(.semibold)
                                    .foregroundColor(.white.opacity(0.7))
                            } icon: {
                                Text("62,354,659")
                                    .fontWeight(.semibold)
                            }
                            .font(.caption)
                        }
                        .padding(.horizontal)
                        .padding(.bottom,25)
                        .frame(maxWidth: .infinity,alignment: .leading)
                    }
                })
                .cornerRadius(15)
                .offset(y: -minY)
        }
        .frame(height: 250)
    }
    
    // 固定在头部
    @ViewBuilder
    func PinnedHeaderView()->some View{
        let types: [String] = ["Popular","Albums","Songs","Fans also like","About"]
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 25){
                
                ForEach(types,id: \.self){type in
                    VStack(spacing: 12){
                        
                        Text(type)
                            .fontWeight(.semibold)
                            .foregroundColor(currentType == type ? .white : .gray)
                        
                        ZStack{
                            if currentType == type{
                                RoundedRectangle(cornerRadius: 4, style: .continuous)
                                    .fill(.white)
                                    .matchedGeometryEffect(id: "TAB", in: animation)
                            }
                            else{
                                RoundedRectangle(cornerRadius: 4, style: .continuous)
                                    .fill(.clear)
                            }
                        }
                        .padding(.horizontal,8)
                        .frame(height: 4)
                    }
                    .contentShape(Rectangle())
                    .onTapGesture {
                        withAnimation(.easeInOut){
                            currentType = type
                        }
                    }
                }
            }
            .padding(.horizontal)
            .padding(.top,25)
            .padding(.bottom,5)
        }
    }
}

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

OffsetModifier - 主要是监听ScrollView的滚动

用来监听ScrollView的滚动 偏移量的改变

//
//  OffsetModifier.swift
//  SpotifyResponvieUI (iOS)
//
//  Created by lyh on 2022/8/23.
//

import SwiftUI

// 继承于 ViewModifier 最主要是能方便扩展一些常见的设置属性
/*
 比如 给Text设置字体\背景颜色\阴影效果
 extension Text {
     func songStyle() -> some View {
         self
             .font(.system(size: 24, weight: .bold))
             .foregroundColor(.white)
             .shadow(radius: 20)
     }
 }
 
 ⭐️如果是继承ViewModifier
 struct SongTextViewModifier: ViewModifier {
     func body(content: Content) -> some View {
         content
           .font(.system(size: 24, weight: .bold))
           .foregroundColor(.white)
           .shadow(radius: 20)
     }
 }

 然后直接通过
 
 Text(song)
       .modifier(SongTextViewModifier())
 设置
 */

struct OffsetModifier: ViewModifier {
    @Binding var offset: CGFloat
    
    // 可选从0返回值
    var returnFromStart: Bool = true
    @State var startValue: CGFloat = 0
    
    func body(content: Content) -> some View {
        content
            .overlay {
                GeometryReader{proxy in
                    Color.clear
                        .preference(key: OffsetKey.self, value: proxy.frame(in: .named("SCROLL")).minY)
                        .onPreferenceChange(OffsetKey.self) { value in
                            if startValue == 0{
                                startValue = value
                            }
                            print(value);

                            offset = (value - (returnFromStart ? startValue : 0))
                            
                            print("offset is \(offset)");

                        }
                }
            }
    }
}

// 偏好的关键
struct OffsetKey: PreferenceKey{
    static var defaultValue: CGFloat = 0
    
    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
        value = nextValue()
    }
}

Album - 模型

//
//  Album.swift
//  SpotifyResponvieUI (iOS)
//
//  Created by lyh on 2022/8/23.
//

import SwiftUI

// Ablum模型和样本数据
struct Album: Identifiable {
    var id = UUID().uuidString
    var albumName: String
    var albumImage : String
    var isLiked : Bool = false
}


var albums : [Album] = [
    
    Album(albumName: "Positions", albumImage: "Album1"),
    Album(albumName: "The Best", albumImage: "Album2",isLiked: true),
    Album(albumName: "My Everything", albumImage: "Album3"),
    Album(albumName: "Yours Truly", albumImage: "Album4"),
    Album(albumName: "Sweetener", albumImage: "Album5",isLiked: true),
    Album(albumName: "Rain On Me", albumImage: "Album6"),
    Album(albumName: "Stuck With U", albumImage: "Album7"),
    Album(albumName: "7 rings", albumImage: "Album8",isLiked: true),
    Album(albumName: "Bang Bang", albumImage: "Album9"),
    
]