_UINavigationBarBackIndicatorView 造成自定义的返回按钮与默认返回按钮同时显示

[Bill Zhuang]

if ([obj isKindOfClass:NSClassFromString(@"_UINavigationBarBackIndicatorView")]) {
 -            obj.alpha = obj.alpha == 0 ? 0 : alpha;
 +            obj.alpha = alpha;
}

更新到新版本后，如果调用lt_setElementsAlpha方法会导致系统的返回按钮显示出来

[溪枫JK]

NSArray * leftViews = [self valueForKey:@"_leftViews"];
if (leftViews.count) {
backIndicator.alpha = alpha;
} else {
backIndicator.alpha = 0;
}