objective-c - IOS中的循环进度条




cocoa-touch ios5 ios4 ios6 (6)

我想创建一个如下所示的循环进度条:

我怎么能用Objective-C和Cocoa做到这一点?

我如何开始这样做是创建一个UIView并编辑drawRect,但我有点迷失。 任何帮助将不胜感激。

谢谢!


Answers

基本概念是使用UIBezierPath类来获得优势。 你可以绘制弧线,达到你想要的效果。 我只有半个小时的时间来解决这个问题,但我的尝试是在下面。

非常简陋,它只是在路径上使用了一个笔划,但我们走了。 您可以根据您的确切需要更改/修改它,但执行弧倒计时的逻辑将非常相似。

在视图类中:

@interface TestView () {
    CGFloat startAngle;
    CGFloat endAngle;
}

@end

@implementation TestView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        self.backgroundColor = [UIColor whiteColor];

        // Determine our start and stop angles for the arc (in radians)
        startAngle = M_PI * 1.5;
        endAngle = startAngle + (M_PI * 2);

    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    // Display our percentage as a string
    NSString* textContent = [NSString stringWithFormat:@"%d", self.percent];

    UIBezierPath* bezierPath = [UIBezierPath bezierPath];

    // Create our arc, with the correct angles
    [bezierPath addArcWithCenter:CGPointMake(rect.size.width / 2, rect.size.height / 2) 
                          radius:130 
                      startAngle:startAngle
                        endAngle:(endAngle - startAngle) * (_percent / 100.0) + startAngle
                       clockwise:YES];

    // Set the display for the path, and stroke it
    bezierPath.lineWidth = 20;
    [[UIColor redColor] setStroke];
    [bezierPath stroke];

    // Text Drawing
    CGRect textRect = CGRectMake((rect.size.width / 2.0) - 71/2.0, (rect.size.height / 2.0) - 45/2.0, 71, 45);
    [[UIColor blackColor] setFill];
    [textContent drawInRect: textRect withFont: [UIFont fontWithName: @"Helvetica-Bold" size: 42.5] lineBreakMode: NSLineBreakByWordWrapping alignment: NSTextAlignmentCenter];
}

对于视图控制器:

@interface ViewController () {    
    TestView* m_testView;
    NSTimer* m_timer;
}

@end

- (void)viewDidLoad
{
    // Init our view
    [super viewDidLoad];
    m_testView = [[TestView alloc] initWithFrame:self.view.bounds];
    m_testView.percent = 100;
    [self.view addSubview:m_testView];
}

- (void)viewDidAppear:(BOOL)animated
{
    // Kick off a timer to count it down
    m_timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(decrementSpin) userInfo:nil repeats:YES];
}

- (void)decrementSpin
{
    // If we can decrement our percentage, do so, and redraw the view
    if (m_testView.percent > 0) {
        m_testView.percent = m_testView.percent - 1;
        [m_testView setNeedsDisplay];
    }
    else {
       [m_timer invalidate];
       m_timer = nil;
    }
}

对于Swift使用这个,

let circle = UIView(frame: CGRectMake(0,0, 100, 100))

circle.layoutIfNeeded()

let centerPoint = CGPoint (x: circle.bounds.width / 2, y: circle.bounds.width / 2)
let circleRadius : CGFloat = circle.bounds.width / 2 * 0.83

var circlePath = UIBezierPath(arcCenter: centerPoint, radius: circleRadius, startAngle: CGFloat(-0.5 * M_PI), endAngle: CGFloat(1.5 * M_PI), clockwise: true    )

let progressCircle = CAShapeLayer()
progressCircle.path = circlePath.CGPath
progressCircle.strokeColor = UIColor.greenColor().CGColor
progressCircle.fillColor = UIColor.clearColor().CGColor
progressCircle.lineWidth = 1.5
progressCircle.strokeStart = 0
progressCircle.strokeEnd = 0.22

circle.layer.addSublayer(progressCircle)

self.view.addSubview(circle)

参考:见Here


我已经为iOS实现了一个简单的库。 它基于UILabel类,因此您可以在进度条中显示您想要的任何内容,但您也可以将其留空。

初始化后,您只需要一行代码来设置进度:

[_myProgressLabel setProgress:(50/100))];

该库名为KAProgressLabel



Swift 3使用这个,

CAShapeLayer with Animation:继续使用Zaid Pathan ans。

    let circle = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))

    circle.layoutIfNeeded()

    var progressCircle = CAShapeLayer()

    let centerPoint = CGPoint (x: circle.bounds.width / 2, y: circle.bounds.width / 2)
    let circleRadius : CGFloat = circle.bounds.width / 2 * 0.83

    let circlePath = UIBezierPath(arcCenter: centerPoint, radius: circleRadius, startAngle: CGFloat(-0.5 * M_PI), endAngle: CGFloat(1.5 * M_PI), clockwise: true    )

    progressCircle = CAShapeLayer ()
    progressCircle.path = circlePath.cgPath
    progressCircle.strokeColor = UIColor.green.cgColor
    progressCircle.fillColor = UIColor.clear.cgColor
    progressCircle.lineWidth = 2.5
    progressCircle.strokeStart = 0
    progressCircle.strokeEnd = 1.0
     circle.layer.addSublayer(progressCircle)


    let animation = CABasicAnimation(keyPath: "strokeEnd")
    animation.fromValue = 0
    animation.toValue = 1.0
    animation.duration = 5.0
    animation.fillMode = kCAFillModeForwards
    animation.isRemovedOnCompletion = false
     progressCircle.add(animation, forKey: "ani")

    self.view.addSubview(circle)

As per the docs , as of iOS 3.0, the UITableViewController class automatically resizes and repositions its table view when there is in-line editing of text fields. I think it's not sufficient to put the text field inside a UITableViewCell as some have indicated.

From the docs :

A table view controller supports inline editing of table view rows; if, for example, rows have embedded text fields in editing mode, it scrolls the row being edited above the virtual keyboard that is displayed.





objective-c cocoa-touch ios5 ios4 ios6