ios12更新开发者需要做什么

1.StatusBar内部结构改变

现象：crash

crash log：

-[_UIStatusBarIdentifier isEqualToString:]: unrecognized selector sent to instance 0x283452820

* Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘-[_UIStatusBarIdentifier isEqualToString:]: unrecognized selector sent to instance 0x283452820

问题代码和解决方法

+ (NSString *)getIphoneXNetWorkStates {

UIApplication *app = [UIApplication sharedApplication];

id statusBar = [[app valueForKeyPath:@"statusBar"] valueForKeyPath:@"statusBar"];

id one = [statusBar valueForKeyPath:@"regions"];

id two = [one valueForKeyPath:@"trailing"];

NSArray *three = [two valueForKeyPath:@"displayItems"];

NSString *state = @"无网络";

for (UIView *view in three)

{ //alert: iOS12.0 情况下identifier的变成了类"_UIStatusBarIdentifier"而不是NSString，所以会在调用“isEqualToString”方法时发生crash

//修改前 // NSString *identifier = [view valueForKeyPath:@"identifier"];

//修改后

NSString *identifier = [[view valueForKeyPath:@"identifier"] description];

if ([identifier isEqualToString:@"_UIStatusBarWifiItem.signalStrengthDisplayIdentifier"]) {

id item = [view valueForKeyPath:@"_item"]; //alert: 这个问题和上边一样itemId是_UIStatusBarIdentifier 类型，不是string

NSString *itemId = [[item valueForKeyPath:@"identifier"] description];

if ([itemId isEqualToString:@"_UIStatusBarWifiItem"]) {

state = @"WIFI"; } state = @"不确定"; } else if ([identifier isEqualToString:@"_UIStatusBarCellularItem.typeDisplayIdentifier"]) {

UIView *statusBarStringView = [view valueForKeyPath:@"_view"]; // 4G/3G/E state = [statusBarStringView valueForKeyPath:@"text"];

} } return state;

}

2.[UIImage imageNamed:]不能正常加载Assets中的图片

解决： 
将图片放到bundle中 
使用一下方式加载即可

NSString *path = [[NSBundle mainBundle] pathForResource:@"bg_login" ofType:@"png"]; _backgroundView = [[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile:path]];

这个不能正常加载的情况只出现在个别的地方，目前找到的共性是加载的图片偏大.

其他bug 参考

https://juejin.im/post/5b1634f0f265da6e61788998