ios自绘UIView进度条及刷新重影解决

记录下，直接上代码
自绘控件，如果包含子控件的话，刷新会有问题，如本进度条中的文本，显示会有重影。

可以创建控件，然后隐藏控件 hidden = YES; 然后在 drawRect中调用控件的 drawRect方法，可以省去text 的draw函数，去了解一些绘制参数，直接设置控件参数，让控件自己去绘制，简单好用。

#import <UIKit/UIKit.h>

@interface VRUpingToolBar : UIView

@property (nonatomic, strong) UILabel *labValue;

@property (nonatomic, assign) CGFloat  progress;

@property (nonatomic, strong) UIColor  *tinkColor;

@property (nonatomic, strong) UIColor  *normalColor;

- (void) setLabsValue:(NSString*)val;

@end

实现文件

#import "VRUpingToolBar.h"

@implementation VRUpingToolBar

- (instancetype) initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if(self){
        [self setupView];
    }
    return self;
}
- (instancetype) init{
    self = [super init];
    if(self){
        [self setupView];
    }
    return self;
}
- (void) setupView{
    _labValue = [UILabel new];
    _labValue.text = @"正在上传第1/1张照片";
    _labValue.textColor = RGB(255,255,255);
    _labValue.textAlignment = NSTextAlignmentCenter;
    _labValue.font = [UIFont systemFontOfSize:12.0F];
    [self addSubview:_labValue];
    WS(ws);
    [_labValue mas_makeConstraints:^(MASConstraintMaker *make) {
        make.center.mas_equalTo(ws);
        make.size.mas_equalTo(ws);
    }];
    _labValue.hidden = YES;//隐藏控件，自己去主动绘制

    _tinkColor = RGB(255, 160, 0);
    _normalColor = RGB(187, 187, 187);
    _progress = 0.2f;
}
- (void)drawRect:(CGRect)rect{
    NSLog(@"upload progress draw %.2f", _progress);
    CGContextRef context = UIGraphicsGetCurrentContext();//context:一块内存区域，将它看做当前view的画布就行了。

    CGRect rc;

    [_normalColor set];

    CGContextFillRect(context, self.bounds);
    rc = self.bounds;
    CGRectOffset(rc, -self.width*(1- self.progress), 0);
    rc.size.width = self.width * self.progress;
    [_tinkColor set];
    CGContextFillRect(context, rc);
    CGContextStrokePath(context);
    [_labValue drawRect:rect];//绘制文本
}

-(void) setProgress:(CGFloat)progress{
    _progress = progress;
    NSLog(@"upload progress-- %.2f", progress);
    [self setNeedsDisplay];
}

- (void) setLabsValue:(NSString*)val{
    self.labValue.text = val;
    [self setNeedsDisplay];
}