Swift SDWebImage没有';行不通

Swift SDWebImage没有';行不通,swift,string,url,uiimageview,sdwebimage,Swift,String,Url,Uiimageview,Sdwebimage,我做错了什么?一切都在运行,但我没有得到图像,救命!谢谢 import UIKit import Firebase import FirebaseDatabase import SDWebImage struct postStruct { let title : String! let downloadURL : String! } class ZeroHomeViewController: UITableViewController { var posts = [

我做错了什么?一切都在运行,但我没有得到图像,救命!谢谢

import UIKit
import Firebase
import FirebaseDatabase
import SDWebImage

struct postStruct {
    let title : String!
    let downloadURL : String!

}

class ZeroHomeViewController: UITableViewController {
    var posts = [postStruct]()

    override func viewDidLoad() {
        super.viewDidLoad()
        let ref = Database.database().reference().child("Posts")
        ref.observeSingleEvent(of: .value, with: { snapshot in

            print(snapshot.childrenCount)

            for rest in snapshot.children.allObjects as! [DataSnapshot] {

                guard let value = rest.value as? Dictionary<String,Any> else { continue }
                guard let  title = value["Title"] as? String else { continue }
                guard let  downloadURL = value["Download URL"] as? String else { continue }
                let post = postStruct(title: title, downloadURL: downloadURL)
                self.posts.append(post)
            }

            self.posts = self.posts.reversed(); self.tableView.reloadData()

        })
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return posts.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
        let imageView = cell?.viewWithTag(200) as! UIImageView

        imageView.sd_setImage(with: URL(string: "downloadUrl"), placeholderImage: UIImage(named: "placeholder.png"))

        let label1 = cell?.viewWithTag(1) as! UILabel
        label1.text = posts[indexPath.row].title
        return cell!
    } 
}
导入UIKit
进口火基
导入FirebaseDatabase
导入SDWebImage
结构后结构{
让标题:字符串!
让我们下载URL:String!
}
类ZeroHomeViewController:UITableViewController{
var posts=[postStruct]()
重写func viewDidLoad(){
super.viewDidLoad()
让ref=Database.Database().reference().child(“Posts”)
ref.observeSingleEvent(的值为:,其中:{snapshot in
打印(快照.childrenCount)
对于snapshot.children.allObjects中的rest![DataSnapshot]{
guard let value=rest.value as?Dictionary else{continue}
guard let title=值[“title”]为字符串,否则{continue}
guard let downloadURL=value[“Download URL”]as?String else{continue}
let post=postStruct(标题:title,downloadURL:downloadURL)
self.posts.append(post)
}
self.posts=self.posts.reversed();self.tableView.reloadData()
})
}
重写func tableView(tableView:UITableView,numberofrowsinssection:Int)->Int{
返回岗位数
}
重写func tableView(tableView:UITableView,cellForRowAt indexath:indexPath)->UITableViewCell{
let cell=tableView.dequeueReusableCell(带标识符:“cell”)
让imageView=单元格?.viewWithTag(200)作为!UIImageView
imageView.sd_setImage(带:URL(字符串:“downloadUrl”)、占位符图像:UIImage(名为:“placeholder.png”))
设label1=单元格?.viewWithTag(1)为!UILabel
label1.text=posts[indexPath.row].title
返回单元!
} 
}
其次

更换这条线 imageView.sd_setImage(带:URL(字符串:“downloadUrl”)、占位符图像:UIImage(名为:“placeholder.png”))

用这个

imageView.sd_setImage(带:URL(字符串:“www.domain.com/URL”)、占位符image:UIImage(名为:“placeholder.png”))

其次,确保编辑所需图像的url

更换这条线 imageView.sd_setImage(带:URL(字符串:“downloadUrl”)、占位符图像:UIImage(名为:“placeholder.png”))

用这个

imageView.sd_setImage(带:URL(字符串:“www.domain.com/URL”)、占位符image:UIImage(名为:“placeholder.png”))

请确保编辑所需图像的url