//设置图片
[self.slider setThumbImage:[UIImage imageNamed:@"sc_video_play_progress_current_position_icon@2x.png"] forState:UIControlStateNormal];
//设置图片后UISlider拖不到起始位置和末位置 需要重写次方法
-(CGRect)thumbRectForBounds:(CGRect)bounds trackRect:(CGRect)rect value:(float)value{
rect.origin.x=rect.origin.x-10;
rect.size.width=rect.size.width+20;
return CGRectInset([super thumbRectForBounds:bounds trackRect:rect value:value],10,10);
}
