ios11 - 从状态栏崩溃中获取蜂窝信号

Question

下面是我的代码，我试图通过状态栏获取信号强度。

UIApplication *app = [UIApplication sharedApplication];
NSArray *subviews = [[[app valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];

崩溃发生在(iOS 11、Xcode 9、iPhone X):-

[UIStatusBar_Modern valueForUndefinedKey:]: 此类对于键 foregroundView 不符合键值编码标准

Answer 1

你可以用这个

NSArray *subviews = nil;
id statusBar = [[UIApplication sharedApplication] valueForKey:@"statusBar"];
if ([statusBar isKindOfClass:NSClassFromString(@"UIStatusBar_Modern")]) {
    subviews = [[[statusBar valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
} else {
    subviews = [[statusBar valueForKey:@"foregroundView"] subviews];
}