Question

我的应用中有一个循环进度条，显示用户所花费的预算百分比。它似乎有效，但除非我在多任务中关闭应用程序并重新打开它，否则它不会更新。

在做了一些研究后，我发现我应该用setNeedsDisplay重新加载它，但是这并没有解决问题。

这是我的drawRect（）代码：

var progress: CGFloat = 0

class ProgressCircle: UIView {

override func drawRect(rect: CGRect) {
    var ctx = UIGraphicsGetCurrentContext()

    var innerRadiusRatio: CGFloat = 0.6

    var path: CGMutablePathRef = CGPathCreateMutable()
    var startAngle: CGFloat = CGFloat(-M_PI_2)
    var endAngle: CGFloat = CGFloat(-M_PI_2) + min(1.0, progress) * CGFloat(M_PI * 2)
    var outerRadius: CGFloat = CGRectGetWidth(self.bounds) * 0.5 - 1.0
    var innerRadius: CGFloat = outerRadius * innerRadiusRatio
    var center = CGPointMake(CGRectGetMidX(rect), CGRectGetMidY(rect))

    //Code for background circle

    var context: CGContextRef = UIGraphicsGetCurrentContext()
    CGContextSetFillColorWithColor(context, (UIColor.darkGrayColor()).CGColor)
    var rectangle: CGRect = CGRectMake(0, 0, 171, 171)
    CGContextBeginPath(context)
    CGContextAddEllipseInRect(context, rectangle)
    CGContextDrawPath(context, kCGPathFill)

    UIGraphicsEndImageContext()

    CGContextSetFillColorWithColor(context, (UIColorFromRGB(0xEAEAEA)).CGColor)
    var rectangleSmall: CGRect = CGRectMake(35.95, 35.95, 99.1, 99.1) //102.6
    CGContextBeginPath(context)
    CGContextAddEllipseInRect(context, rectangleSmall)
    CGContextDrawPath(context, kCGPathFill)

    UIGraphicsEndImageContext()

    //Code for progress radius

    CGPathAddArc(path, nil, center.x, center.y, innerRadius, startAngle, endAngle, false)
    CGPathAddArc(path, nil, center.x, center.y, outerRadius, endAngle, startAngle, true)
    CGPathCloseSubpath(path)
    CGContextAddPath(ctx, path)

    CGContextSaveGState(ctx)
    CGContextClip(ctx)
    if percent > 100 {
        CGContextDrawImage(ctx, self.bounds, UIImage(named: "RadialProgressFillOver").CGImage)
    } else {
        CGContextDrawImage(ctx, self.bounds, UIImage(named: "RadialProgressFill").CGImage)
    }
    CGContextRestoreGState(ctx)
}

这就是我尝试重新加载进度圈的方法：

override func viewDidAppear(animated: Bool) {
    //Show set up screen if user hasn't used AffordIt before.

    userReturned = NSUserDefaults.standardUserDefaults().boolForKey("userReturnedCheck")
    if userReturned == false {
        self.performSegueWithIdentifier("setupView", sender: self)
    }

    //Add circular progress bar to budget display view.

    progress = CGFloat(percent/100)
    var circleFrame = CGRect(x: 75, y: 249, width: 171, height: 171)
    var circle = ProgressCircle(frame: circleFrame)
    self.budgetDisplayView.addSubview(circle)
    self.budgetDisplayView.sendSubviewToBack(circle)
    circle.setNeedsDisplay()
    view.setNeedsDisplay()

    circle.backgroundColor = UIColor.clearColor()
}

setNeedsDisplay没有更新UIView

0 个答案: