PROSAGA码农传奇-swift/objective-C-Objective-C UIImage凹面角（又名自定义进度条）

<div class =“post-text”itemprop =“text”>
  
    我可能只是应用一个而不是创建任何图像
     <code>
 cornerRadius
 </code>
     同时显示主要进度视图以及显示进度的视图。因此，想象一下以下视图层次结构：
  
  
    <a href="https://i.stack.imgur.com/g6XL2.png" rel="nofollow noreferrer">
      <img src =“https://i.stack.imgur.com/g6XL2.png”alt =“在此处输入图片说明”/>
    </A>
  
  
    主要进展视图是背面的白色边框视图。这有一个子视图，
     <code>
 progressSubview
 </code>
     （在上面以蓝色突出显示），显示了迄今为止的进展（并且会随着我们更新而改变
     <code>
 progress
 </code>
     属性）。绿色和蓝色视图只是固定大小的子视图
     <code>
 progressSubview
 </code>
     被揭示为
     <code>
 progressSubview
 </code>
    剪辑其子视图，改变大小。
  
  
    应用角半径非常容易。并通过避免任何图像或自定义
     <code>
 drawRect
 </code>
    ，我们可以动画的变化
     <code>
 progressSubview
 </code>
     如果我们想要：
  
  
    <a href="https://i.stack.imgur.com/wg9Ua.gif" rel="nofollow noreferrer">
      <img src =“https://i.stack.imgur.com/wg9Ua.gif”alt =“在此输入图像说明”/>
    </A>
  
  
    例如。
  
   <pre>
 <code>
 // CustomProgressView.h

@import UIKit;

NS_ASSUME_NONNULL_BEGIN

IB_DESIGNABLE
@interface CustomProgressView : UIView

@property (nonatomic) CGFloat progress;

@end

NS_ASSUME_NONNULL_END

</code>
 </pre>
  
    和
  
   <pre>
 <code>
 // CustomProgressView.m

#import "CustomProgressView.h"

@interface CustomProgressView ()

@property (nonatomic, weak) UIView *progressSubview;
@property (nonatomic, weak) UIView *greenView;
@property (nonatomic, weak) UIView *redView;

@end

@implementation CustomProgressView

- (instancetype)init {
    return [self initWithFrame:CGRectZero];
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder {
    if ((self = [super initWithCoder:aDecoder])) {
        [self configure];
    }
    return self;
}

- (instancetype)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {
        [self configure];
    }
    return self;
}

- (void)configure {
    UIView *subview = [[UIView alloc] init];
    subview.backgroundColor = [UIColor clearColor];
    subview.clipsToBounds = true;
    self.layer.borderColor = [[UIColor whiteColor] CGColor];
    self.layer.borderWidth = 1;

UIView *redView = [[UIView alloc] init];
    redView.backgroundColor = [UIColor redColor];
    self.redView = redView;

UIView *greenView = [[UIView alloc] init];
    greenView.backgroundColor = [UIColor greenColor];
    self.greenView = greenView;

[self addSubview:subview];
    [subview addSubview:redView];
    [subview addSubview:greenView];

self.progressSubview = subview;
}

- (void)layoutSubviews {
    [super layoutSubviews];

self.layer.cornerRadius = MIN(self.bounds.size.height, self.bounds.size.width) / (CGFloat)2.0;
    self.progressSubview.layer.cornerRadius = MIN(self.bounds.size.height, self.bounds.size.width) / (CGFloat)2.0;
    [self updateProgressSubview];

self.redView.frame = self.bounds;

CGRect rect = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.bounds.origin.x + self.bounds.size.width / 2.0, self.bounds.origin.y + self.bounds.size.height);
    self.greenView.frame = rect;
}

- (void)setProgress:(CGFloat)progress {
    _progress = progress;
    [self updateProgressSubview];
}

- (void)updateProgressSubview {
    CGRect rect = CGRectMake(self.bounds.origin.x, self.bounds.origin.y, self.bounds.origin.x + self.bounds.size.width * self.progress, self.bounds.origin.y + self.bounds.size.height);
    self.progressSubview.frame = rect;
}

- (void)prepareForInterfaceBuilder {
    [super prepareForInterfaceBuilder];

self.progress = 0.75;
}

@end

</code>
 </pre>
  
    然后你可以像这样更新进度：
  
   <pre>
 <code>
 [UIView animateWithDuration:0.25 animations:^{
 self.progressView.progress = 0.75;
}];

</code>
 </pre>
  <HR />
  <BLOCKQUOTE>
    
      ...我在'UIView *'语义警告类型的对象上找不到属性“进度”
    
  </BLOCKQUOTE>
  
    看起来你的
     <code>
 IBOutlet
 </code>
     被定义为a
     <code>
 UIView
 </code>
     而不是一个
     <code>
 CustomProgressView
 </code>
    。
  
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