[摘要]本文是對自定義的進度條的講解，對學習IOS蘋果軟件開發有所幫助,與大家分享。

/** 初始化一個progress，
 aFrame                    外層的大小
 aFrameColor         外層的顏色
 aBarColor               裡層的顏色
 gapSize                   裡層和外層的間隙
 **/

- (id)initWithFrame:(CGRect)aFrame frameColor:(UIColor *)aFrameColor barColor:(UIColor *)aBarColor aFrameCornerRadius:(CGFloat)aFrameCornerRadius aFrameBorderColor:(CGColorRef)aFrameBorderColor gapSize:(CGFloat)gapSize
{
    self = [super initWithFrame:aFrame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
        _gap = gapSize;
        
        _outter = [[UILabel alloc]init];
        _outter.frame = self.bounds;
        _outter.backgroundColor = aFrameColor;
        _outter.layer.borderWidth = 1;
        _outter.layer.borderColor = aFrameBorderColor;
        [self addSubview:_outter];
        
        _inner = [[UILabel alloc]init];
        _inner.frame = CGRectZero;
        _inner.backgroundColor = aBarColor;
        [self addSubview:_inner];
        
        _inner.layer.cornerRadius = aFrameCornerRadius - gapSize;
        _inner.layer.masksToBounds = YES;
        _outter.layer.cornerRadius = aFrameCornerRadius;
        _outter.layer.masksToBounds = YES;
    }
    return self;
}


- (void)setProgress:(float)progress
{
    progress = progress<0?0:progress;
    progress = progress>1?1:progress;
    _inner.frame = CGRectMake(_gap, _gap, progress*(self.frame.size.width - _gap*2.0), self.frame.size.height - _gap *2.0);
}

- (void)dealloc
{
    [_inner removeFromSuperview];
    [_outter removeFromSuperview];
}