在UIButton中放置一个UIActivityIndi​​cator

Question

我知道我错过了一些愚蠢的东西，但无论如何，这是我的代码：

UIActivityIndicatorView indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
indicator.hidesWhenStopped = YES;
indicator.frame = btnLogin.frame;
indicator.center = btnLogin.center;
[self.view addSubview:indicator];
[indicator bringSubviewToFront:indicator];

以下是最终结果：

http://img542.imageshack.us/img542/8172/uiactivity.png

提前谢谢！

Answer 1

我认为您缺少的概念是视图的框架（及其中心）都与其超视图相关。根据你的截图，我猜你的文本字段和按钮都在一个充当容器的视图中。所以你的按钮框架＆amp; center与容器视图有关，而不是视图控制器的整体视图。您指定相同的框架＆amp;以活动指示器为中心，然后将指标添加为主视图的子视图，而不是容器视图。所以你现在有两个具有相同框架的视图（按钮和指示器），但该框架与两个不同的超视图相关。

最简单的更改就是将指标添加到您正在使用的容器视图中。但我建议将指标添加为按钮的子视图，然后只需做一些数学运算来调整其位置。

UIActivityIndicatorView *indicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
CGFloat halfButtonHeight = btnLogin.bounds.size.height / 2;
CGFloat buttonWidth = btnLogin.bounds.size.width;
indicator.center = CGPointMake(buttonWidth - halfButtonHeight , halfButtonHeight);
[btnLogin addSubview:indicator];
[indicator startAnimating];

作为旁注：您在视图框架之后设置视图中心是多余的。此外，作为子视图添加的最后一个视图自动成为前子视图。

Answer 2

根据@Musa almatri的回答，我创建了扩展名：

extension UIButton {
func loadingIndicator(show show: Bool) {
    let tag = 9876
    if show {
        let indicator = UIActivityIndicatorView()
        let buttonHeight = self.bounds.size.height
        let buttonWidth = self.bounds.size.width
        indicator.center = CGPointMake(buttonWidth/2, buttonHeight/2)
        indicator.tag = tag
        self.addSubview(indicator)
        indicator.startAnimating()
    } else {
        if let indicator = self.viewWithTag(tag) as? UIActivityIndicatorView {
            indicator.stopAnimating()
            indicator.removeFromSuperview()
        }
    }
}}

然后你可以像这样使用它：

yourButton.loadingIndicator(show: true) //hide -> show: false

Answer 3

这是Swift 3版本，不使用标签。

import UIKit

extension UIButton {
    func loadingIndicator(show: Bool) {
        if show {
            let indicator = UIActivityIndicatorView()
            let buttonHeight = self.bounds.size.height
            let buttonWidth = self.bounds.size.width
            indicator.center = CGPoint(x: buttonWidth/2, y: buttonHeight/2)
            self.addSubview(indicator)
            indicator.startAnimating()
        } else {
            for view in self.subviews {
                if let indicator = view as? UIActivityIndicatorView {
                    indicator.stopAnimating()
                    indicator.removeFromSuperview()
                }
            }
        }
    }
}

Answer 4

快速解决方案：

var indicator = UIActivityIndicatorView()
var halfButtonHeight = SOME_BUTTON.bounds.size.height / 2;
var buttonWidth = SOME_BUTTON.bounds.size.width;
indicator.center = CGPointMake(buttonWidth - halfButtonHeight , halfButtonHeight);
SOME_BUTTON.addSubview(indicator)
indicator.startAnimating()

并将其置于按钮的中心

indicator.center = CGPointMake(buttonWidth/2, halfButtonHeight);

或使用优质图书馆

https://github.com/souzainf3/RNLoadingButton-Swift

Answer 5

小升级:(在superview上添加按钮）

extension UIButton {
    func loadingIndicator(_ show: Bool) {
        let indicatorTag = 808404
        if show {
            isEnabled = false
            alpha = 0
            let indicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
            indicator.center = center
            indicator.tag = indicatorTag
            superview?.addSubview(indicator)
            indicator.startAnimating()
        } else {
            isEnabled = true
            alpha = 1.0
            if let indicator = superview?.viewWithTag(indicatorTag) as? UIActivityIndicatorView {
                indicator.stopAnimating()
                indicator.removeFromSuperview()
            }
        }
    }
}

Answer 6

我使用约束将指示器置于UIButton内。 调整@DanielQ的扩展名，即：

extension UIButton {
    func loadingIndicator(show: Bool) {
        let tag = 9876
        if show {
            let indicator = UIActivityIndicatorView()
            indicator.tag = tag
            self.addSubview(indicator)
            indicator.translatesAutoresizingMaskIntoConstraints = false
            let horizontalConstraint = NSLayoutConstraint(item: indicator, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerX, multiplier: 1, constant: 0)
            let verticalConstraint = NSLayoutConstraint(item: indicator, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: self, attribute: NSLayoutAttribute.centerY, multiplier: 1, constant: 0)
            self.addConstraints([horizontalConstraint, verticalConstraint])
            indicator.startAnimating()
        } else {
            if let indicator = self.viewWithTag(tag) as? UIActivityIndicatorView {
                indicator.stopAnimating()
                indicator.removeFromSuperview()
            }
        }
    }
}

Answer 7

我从按钮中删除了标题，然后在动画完成后将其添加回来，而不是覆盖标题的指示符：

extension UIButton {

func loadingIndicator(show: Bool) {
    let tag = 9876

    var color: UIColor?

    if show {
        color = titleColor(for: .normal)
        let indicator = UIActivityIndicatorView()
        let buttonHeight = self.bounds.size.height
        let buttonWidth = self.bounds.size.width
        indicator.center = CGPoint(x: buttonWidth/2, y: buttonHeight/2)
        indicator.tag = tag
        indicator.color = UIColor.white
        setTitleColor(.clear, for: .normal)

        self.addSubview(indicator)
        indicator.startAnimating()
    } else {
        if let indicator = self.viewWithTag(tag) as? UIActivityIndicatorView {
            indicator.stopAnimating()
            indicator.removeFromSuperview()
            setTitleColor(color, for: .normal)
        }
    }
}
}