ios 如何在 iPhone 屏幕中间显示活动指示器？

How to display activity indicator in middle of the iphone screen?

提问by srinivas

When we draw the image, we want to display the activity indicator. Can anyone help us?

当我们绘制图像时，我们希望显示活动指示器。任何人都可以帮助我们吗？

回答by userar

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

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

回答by Rogerio Chaves

If you are using Swift, this is how you do it

如果您使用的是 Swift，这就是您的操作方式

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

self.view.addSubview(activityView)

回答by Suragch

Code updated for Swift 3

为 Swift 3 更新了代码

Swift code

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)
    }
}

Notes

笔记

• You can center the activity indicator in middle of the screen by adding it as a subview to the root viewrather than myBlueSubview.

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

• You can also create the UIActivityIndicatorViewin the Interface Builder. Just drag an Activity Indicator Viewonto the storyboard and set the properties. Be sure to check Hides When Stopped. Use an outlet to call startAnimating()and stopAnimating(). See this tutorial.

• 您可以通过将活动指示器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UIActivityIndicatorView在 Interface Builder 中创建。只需将活动指示器视图拖到情节提要上并设置属性。请务必检查停止时隐藏。使用插座调用startAnimating()和stopAnimating()。请参阅本教程。

• Remember that the default color of the LargeWhitestyle is white. So if you have a white background you can't see it, just change the color to black or whatever other color you want.

  activityIndicator.color = UIColor.black
  

• A common use case would be while a background task runs. Here is an example:

  // 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()
      }
  }
  

• 请记住，LargeWhite样式的默认颜色是白色。因此，如果您有白色背景，您看不到它，只需将颜色更改为黑色或您想要的任何其他颜色。

  activityIndicator.color = UIColor.black
  

• 一个常见的用例是在后台任务运行时。下面是一个例子：

  // 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()
      }
  }
  

回答by D33pN16h7

This is the correct way:

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];

Setup your autoresizing mask if you support rotation. Cheers!!!

如果您支持旋转，请设置您的自动调整大小蒙版。干杯！！！

回答by Anand

Try this way

试试这个方法

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];

回答by DAC84

If you want to add a text along with activity indicator please look at http://nullpointr.wordpress.com/2012/02/27/ios-dev-custom-activityindicatorview/

如果您想添加文本和活动指示器，请查看http://nullpointr.wordpress.com/2012/02/27/ios-dev-custom-activityindicatorview/

回答by Orkhan Huseynov

Swift 4, Autolayout version

Swift 4，自动布局版本

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),
    ])
}

回答by Vasily Bodnarchuk

Swift 3, xcode 8.1

斯威夫特 3，Xcode 8.1

You can use small extension to place UIActivityIndicatorView in the centre of UIViewand inherited UIView classes:

您可以使用小扩展将UIActivityIndi​​catorView放置在 UIView和继承 UIView 类的中心：

Code

代码

extension UIActivityIndicatorView {

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

How to use

如何使用

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

Full Example

完整示例

In this example UIActivityIndicatorView placed in the centre of the ViewControllers view:

在这个例子中 UIActivityIndi​​catorView 放置在 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)
    }
}

回答by Shaheen Ghiassy

If you want to center the spinner using AutoLayout, do:

如果要使用 AutoLayout 将微调器居中，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]];

回答by Minakshi

You can set the position like this

你可以这样设置位置

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

Accordingly change the frame size.....

相应地改变帧大小.....