如何在iPhone屏幕中间显示活动指示灯？

Question

当我们绘制图像时，我们想要显示活动指示器。 有人可以帮助我们吗？

Answer 1

UIActivityIndicatorView *activityView = [[UIActivityIndicatorView alloc]     
        initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];

    activityView.center=self.view.center;
    [activityView startAnimating];
    [self.view addSubview:activityView];

Answer 2

如果您使用的是Swift，这就是您的操作方法

let activityView = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge)
activityView.center = self.view.center
activityView.startAnimating()

self.view.addSubview(activityView)

Answer 3

代码已更新为Swift 3

SWIFT代码

import UIKit
class ViewController: UIViewController {

    let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.whiteLarge)

    @IBOutlet weak var myBlueSubview: UIView!

    @IBAction func showButtonTapped(sender: UIButton) {
        activityIndicator.startAnimating()
    }

    @IBAction func hideButtonTapped(sender: UIButton) {
        activityIndicator.stopAnimating()
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // set up activity indicator
        activityIndicator.center = CGPoint(x: myBlueSubview.bounds.size.width/2, y: myBlueSubview.bounds.size.height/2)
        activityIndicator.color = UIColor.yellow
        myBlueSubview.addSubview(activityIndicator)
    }
}

笔记

• 您可以将活动指示器置于屏幕中间，方法是将其作为子视图添加到根view而不是myBlueSubview 。

   activityIndicator.center = CGPoint(x: self.view.bounds.size.width/2, y: self.view.bounds.size.height/2) self.view.addSubview(activityIndicator) 

• 您还可以在Interface Builder中创建UIActivityIndicatorView 。 只需将活动指示器视图拖到故事板上并设置属性即可。 务必检查隐藏时的隐藏 。 使用插座调用startAnimating()和stopAnimating() 。 请参阅本教程 。

• 请记住， LargeWhite样式的默认颜色是白色。 因此，如果您有白色背景，则无法看到它，只需将颜色更改为黑色或任何其他颜色即可。

   activityIndicator.color = UIColor.black 

• 一个常见的用例是运行后台任务。 这是一个例子：

   // start animating before the background task starts activityIndicator.startAnimating() // background task DispatchQueue.global(qos: .userInitiated).async { doSomethingThatTakesALongTime() // return to the main thread DispatchQueue.main.async { // stop animating now that background task is finished self.activityIndicator.stopAnimating() } } 

Answer 4

这是正确的方法：

UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activityIndicator.center = CGPointMake(self.view.frame.size.width / 2.0, self.view.frame.size.height / 2.0);
[self.view addSubview: activityIndicator];

[activityIndicator startAnimating];

[activityIndicator release];

如果支持旋转，请设置自动调整遮罩。 干杯！！！

Answer 5

如果您想添加文本以及活动指标，请查看http://nullpointr.wordpress.com/2012/02/27/ios-dev-custom-activityindicatorview/

Answer 6

试试这种方式

UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    activityIndicator.frame = CGRectMake(10.0, 0.0, 40.0, 40.0);
    activityIndicator.center = super_view.center;
    [super_view addSubview: activityIndicator];

[activityIndicator startAnimating];

Answer 7

如果要使用AutoLayout使微调器居中，请执行以下操作：

UIActivityIndicatorView *activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
[activityView startAnimating];
[self.view addSubview:activityView];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:activityView
                                                      attribute:NSLayoutAttributeCenterX
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self.view
                                                      attribute:NSLayoutAttributeCenterX
                                                     multiplier:1.0
                                                       constant:0.0]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:activityView
                                                      attribute:NSLayoutAttributeCenterY
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self.view
                                                      attribute:NSLayoutAttributeCenterY
                                                     multiplier:1.0
                                                       constant:0.0]];

Answer 8

Swift 3，xcode 8.1

您可以使用小扩展将UIActivityIndi​​catorView置于UIView的中心并继承UIView类：

码

extension UIActivityIndicatorView {

    convenience init(activityIndicatorStyle: UIActivityIndicatorViewStyle, color: UIColor, placeInTheCenterOf parentView: UIView) {
        self.init(activityIndicatorStyle: activityIndicatorStyle)
        center = parentView.center
        self.color = color
        parentView.addSubview(self)
    }
}

如何使用

let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge, color: .gray,  placeInTheCenterOf: view)
activityIndicator.startAnimating()

完整的例子

在此示例中，UIActivityIndi​​catorView位于ViewControllers视图的中心：

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge, color: .gray,  placeInTheCenterOf: view)
        activityIndicator.startAnimating()
    }
}

extension UIActivityIndicatorView {

    convenience init(activityIndicatorStyle: UIActivityIndicatorViewStyle, color: UIColor, placeInTheCenterOf parentView: UIView) {
        self.init(activityIndicatorStyle: activityIndicatorStyle)
        center = parentView.center
        self.color = color
        parentView.addSubview(self)
    }
}

Answer 9

您可以像这样设置位置

        UIActivityIndicatorView *activityView = 
[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
activityView.frame = CGRectMake(120, 230, 50, 50);
[self.view addSubview:activityView];

因此改变框架尺寸.....

Answer 10

对于Swift 3，您可以使用以下内容：

 func setupSpinner(){
    spinner = UIActivityIndicatorView(frame: CGRect(x: 0, y: 0, width: 40, height:40))
    spinner.color = UIColor(Colors.Accent)
    self.spinner.center = CGPoint(x:UIScreen.main.bounds.size.width / 2, y:UIScreen.main.bounds.size.height / 2)
    self.view.addSubview(spinner)
    spinner.hidesWhenStopped = true
}

Answer 11

Swift 4，Autolayout版本

func showActivityIndicator(on parentView: UIView) {
    let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
    activityIndicator.startAnimating()
    activityIndicator.translatesAutoresizingMaskIntoConstraints = false

    parentView.addSubview(activityIndicator)

    NSLayoutConstraint.activate([
        activityIndicator.centerXAnchor.constraint(equalTo: parentView.centerXAnchor),
        activityIndicator.centerYAnchor.constraint(equalTo: parentView.centerYAnchor),
    ])
}

Answer 12

？如果您想尝试使用界面，可以查看我的视频 。 这样，您无需编写任何代码来在iPhone屏幕中间显示活动指示器。

Answer 13

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var textLbl: UILabel!

    var containerView = UIView()
    var loadingView = UIView()
    var activityIndicator = UIActivityIndicatorView()

    override func viewDidLoad() {
        super.viewDidLoad()

        let _  = Timer.scheduledTimer(withTimeInterval: 10, repeats: false) { (_) in
            self.textLbl.text = "Stop ActivitiIndicator"
            self.activityIndicator.stopAnimating()
            self.containerView.removeFromSuperview()
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    @IBAction func palyClicked(sender: AnyObject){

        containerView.frame = self.view.frame
        containerView.backgroundColor = UIColor(red: 0/255, green: 0/255, blue: 0/255, alpha: 0.3)
        self.view.addSubview(containerView)

        loadingView.frame = CGRect(x: 0, y: 0, width: 80, height: 80)
        loadingView.center = self.view.center
        loadingView.backgroundColor = UIColor(red: 0/255, green: 0/255, blue: 0/255, alpha: 0.5)
        loadingView.clipsToBounds = true
        loadingView.layer.cornerRadius = 10
        containerView.addSubview(loadingView)

        activityIndicator.frame = CGRect(x: 0, y: 0, width: 40, height: 40)
        activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.whiteLarge
        activityIndicator.center = CGPoint(x:loadingView.frame.size.width / 2, y:loadingView.frame.size.height / 2);
        activityIndicator.startAnimating()
        loadingView.addSubview(activityIndicator)

    }
}

Answer 14

轻松解决方案

UIApplication.sharedApplication.networkActivityIndicatorVisible = true/false

Answer 15

希望这会奏效：

// create activity indicator 
UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] 
    initWithFrame:CGRectMake(0.0f, 0.0f, 20.0f, 20.0f)];
[activityIndicator setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleWhite];

...
 [self.view addSubview:activityIndicator];
// release it
[activityIndicator release];

Answer 16

我找到了一种用最少代码显示活动指标的方法：

首先导入你的UI工具包

import UIKit;

然后你必须启动活动指标

let activityIndicator:UIActivityIndicatorView = UIActivityIndicatorView();

然后只需复制粘贴下面的功能，这些功能是自我解释的，并在需要时随时调用它们：

func startLoading(){
    activityIndicator.center = self.view.center;
    activityIndicator.hidesWhenStopped = true;
    activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.gray;
    view.addSubview(activityIndicator);

    activityIndicator.startAnimating();
    UIApplication.shared.beginIgnoringInteractionEvents();

}

func stopLoading(){ 

    activityIndicator.stopAnimating();
    UIApplication.shared.endIgnoringInteractionEvents();

}