Run the program on ios8.1, the program interface only shows part

Running the program on iOS 9.1 is fine but running on 8.1 on the Discovery emulator shows only a small portion of the program's interface, which is not fully displayed.

The result is found to be caused by the following code Setup problem

-(BOOL) Application: (UIApplication *) application didfinishlaunchingwithoptions: (Nsdictionary *) launchOptions {

Self.window = [[UIWindow alloc] init];

Self.window.frame = [[UIScreen mainscreen] bounds];

xxxx

}

The original self.window.bounds = [[UIScreen mainscreen] bounds]; causes window position error

Run the program on ios8.1, the program interface only shows part