小编luk*_*uke的帖子

如何更改uisearchcontroller的背景颜色？它看起来像这样

我想要一个颜色.我试过了sc.view.tintColor = UIColor.rgb(10, green: 150, blue: 255), sc.view.backgroundColor = UIColor.rgb(10, green: 150, blue: 255)但没有移除侧面的灰色位

采用以下JSON:

let rawJson =
"""
[
      {
          "id": 1,
          "name":"John Doe"
      },
      {
          "id": 2,
          "name":"Luke Smith"
      },
 ]
"""

和User型号:

struct User: Decodable {
    var id: Int
    var name: String
}

解码非常简单,如下所示:

let data = rawJson.data(using: .utf8)
let decoder = JSONDecoder()
let users = try! decoder.decode([User].self, from: data!)

但是,如果JSON看起来像这样,顶级是一个字典,需要获取以下数组users:

let json =
"""
{
    "users":
    [
        {
          "id": 1,
          "name":"John Doe"
        },
        {
          "id": 2,
          "name":"Luke Smith"
        },
    ]
}
"""

阅读JSON最有效的解决方案是什么？我绝对可以创建另一个struct这样的:

struct …

如何将邮政编码（或者在我的情况下是邮政编码（英国））转换为经纬度坐标？

我读到了使用谷歌地理编码 API，但读到它有相当多的限制，例如在应用程序中使用谷歌地图和限制请求。

我也发现了这个，但我不确定如何实施它

如何制作淡出的导航栏？顶部的alpha值为0.5,下半部分为0.当它从上到下时,alpha减小,变得更透明.

像这样的东西:

如您所见,当您沿着导航栏移动时,它变得更加透明.

我有一个UINavigationBar 的UIButton内部titleView。我想每次用户点击给定按钮时将插入符号图像向下旋转 180 度。

我有一个像这样的字符串:

var aString = "This is a string \n\n This is the second line of the string\n\n"

textview中的内容如下所示:

This is a string 

This is the second line of the string


// 2 extra lines of unnecessary white space

但我希望它看起来像这样:

This is a string 
This is the second line of the string

我想从字符串的末尾删除所有"\n"并删除\n,它会重复自身,因此中间没有空格.

理想情况下,我猜测最终结果应该是这样的:

var aString = "This is a string \n This is the second line of the string"

我有2个单元格的tableview.两个单元格都有文本字段和标签.Textfield采用用户名/电子邮件地址和密码的值.

var emailAddress: String?
var password: String?

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier(cellID) as! TextFieldCell

    cell.label.text = loginOptions[indexPath.row]
    cell.textField.placeholder = loginOptions[indexPath.row]

    if indexPath.row == 0 {
        emailAddress = cell.textField.text!
    }
    if indexPath.row == 1 {
        password = cell.textField.text!
    }

    return cell
}   

下面是检查文本框中是否有任何文本的功能,如果没有,则显示建议填写所有字段的警报控制器.

func signInButtonTapped() {

    if emailAddress!.isEmpty || password!.isEmpty {

        let alert = UIAlertController(title: "Alert", message: "all fields are required to be filled in", preferredStyle: .Alert)
        let action = UIAlertAction(title: "OK", style: …

我有一个带有3个标签栏按钮的标签栏控制器.目前它看起来像这样:

class CustomTabBarController: UITabBarController {

override func viewDidLoad() {
    super.viewDidLoad()

    let firstTabBarController = FirstController()
    let firstTabBarNavigationController = UINavigationController(rootViewController: firstTabBarController)
    firstTabBarNavigationController.tabBarItem.title = "First Tab"

    let secondTabBarController = SecondController()
    let secondTabBarNavigationController = UINavigationController(rootViewController: secondTabBarController)
    secondTabBarController.tabBarItem.title = "Second Tab"

    let thirdTabBarController = ThirdController()
    let thirdTabBarNavigationController = UINavigationController(rootViewController: thirdTabBarController)
    thirdTabBarNavigationController.tabBarItem.title = "Third Tab"

    viewControllers = [firstTabBarNavigationController, secondTabBarNavigationController, thirdTabBarNavigationController]

}
}

现在,使用上面的代码,所有视图控制器都位于内部 CustomTabBarController

我想要中间的标签栏按钮,secondTabBarNavigationController用于呈现视图控制器,特别UIImagePickerController是用户选择图像,类似于Instagram.

怎么能实现这一目标？我没有使用故事板

func startUploadingImage() {

    var localFileName:String?

// Issue #1: This here causes a segmentation fault 11 - Worked completely fine in swift 2.3
    if let imageToUploadUrl = selectedImageUrl {

        let phResult = PHAsset.fetchAssets(withALAssetURLs: [imageToUploadUrl], options: nil)
        localFileName = phResult.firstObject?.fileManager
    }

    if localFileName == nil {
        return
    }

    // Configure AWS Cognito Credentials
    let myIdentityPoolId = ""

    let credentialsProvider:AWSCognitoCredentialsProvider = AWSCognitoCredentialsProvider(regionType:AWSRegionType.euWest1, identityPoolId: myIdentityPoolId)

    let configuration = AWSServiceConfiguration(region:AWSRegionType.euWest1, credentialsProvider:credentialsProvider)

    AWSServiceManager.default().defaultServiceConfiguration = configuration

    // Set up AWS Transfer Manager Request
    let S3BucketName = "" …

所以我的 vc 中有一个 collectionview，如下所示：

lazy var collectionView : UICollectionView = {
    let layout = UICollectionViewFlowLayout()
    layout.headerReferenceSize = CGSize(width: self.view.frame.width, height: 96 + 42.5)
    let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
    cv.delegate = self
    cv.dataSource = self
    cv.register(UICollectionViewCell.self, forCellWithReuseIdentifier: cellId)
    cv.alwaysBounceVertical = true
    return cv
}()

它有一个总高度为 138.5 像素的标题。所以显示单元格的集合视图的内容大小是view.frame.height - 138.5.

在我的 collectionview 中，我有一个高度为 176 像素的单元格，而view.frame.width宽度像这样：

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    return CGSize(width: view.frame.width, height: 176)
}

问题是，当我返回 3 …

尝试用字符_替换空格

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    if textField.tag == 0 {
        username = textField.text!
        username = username.replacingOccurrences(of: " ", with: "_", options: .literal, range: nil)
        textField.text! = username
    }
    return true
}

麻烦的是，键入空格后的字符后，空格被替换了。

我tableView cellForRowAtIndexPath看起来像这样:

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: CheckoutAppointmentCell.reuseIdentifier) as! CheckoutAppointmentCell
    cell.appointment = appointments[indexPath.row]
    cell.checkoutButton.tag = indexPath.row
    cell.checkoutButton.addTarget(self, action: #selector(checkoutButtonTapped), for: .touchUpInside)
    return cell
}

然后我从删除的预定tableView和dataSource像这样:

func checkoutButtonTapped(sender: UIButton) {
    appointments.remove(at: sender.tag)
    print(sender.tag)
    //self.tableView.beginUpdates()
    self.tableView.deleteRows(at: [IndexPath(row:sender.tag, section: 0)], with: .automatic)
    //self.tableView.endUpdates()
}

我第一次删除约会,它工作正常.该sender.tag值应该是它应该是正确的行从中删除tableView.

删除第一行后,似乎删除了不正确的行.

我在调用reloadData()后尝试调用deleteRows但动画不再出现.beginUpdates()并且endUpdates()似乎没有什么区别都不是.