使用button載入網路圖片顯示異常
iOS11之前正常：

    self.leftButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [self.leftButton addTarget:self action:@selector(leftDrawerButtonPress:) forControlEvents:UIControlEventTouchUpInside];
    self.leftButton.frame = RECT(0, 0, 36, 36);
    self.leftButton.clipsToBounds
 
 = YES;
    self.leftButton.layer.cornerRadius = 16;
    self.leftButton.layer.borderColor = RGBAHex(0xffffff,0.5).CGColor;
    self.leftButton.layer.borderWidth = 1;
    self.leftButton.adjustsImageWhenHighlighted = NO;
    UIBarButtonItem * leftDrawerButton = [[UIBarButtonItem alloc] initWithCustomView:self.leftButton
 
];
    [self.navigationItem setLeftBarButtonItem:leftDrawerButton animated:YES];

iOS11:

    self.leftButton = [UIButton buttonWithType:UIButtonTypeCustom];
    [self.leftButton addTarget:self action:@selector(leftDrawerButtonPress:) forControlEvents:UIControlEventTouchUpInside];
    self.leftButton
 
.frame = RECT(0, 0, 36, 36);
    self.leftButton.clipsToBounds = YES;
    self.leftButton.layer.cornerRadius = 16;
    self.leftButton.layer.borderColor = RGBAHex(0xffffff,0.5).CGColor;
    self.leftButton.layer.borderWidth = 1;
    self.leftButton.adjustsImageWhenHighlighted = NO;
    UIBarButtonItem * leftDrawerButton = [[UIBarButtonItem alloc] initWithCustomView:self.leftButton];
    if ([[[UIDevice currentDevice] systemVersion] doubleValue] >= 11.0) {
        [self.leftButton mas_makeConstraints:^(MASConstraintMaker *make) {
            make.size.equalTo(CGSizeMake(36, 36));
        }];
    }
    [self.navigationItem setLeftBarButtonItem:leftDrawerButton animated:YES];