iOS8 UIAlertView 推出页面后，键盘闪一下的问题，有需要的朋友可以参考下。
iOS8以后，当当前界面有UITextField输入框时，需要点击确定pop到上一个页面时，会出现pop界面后键盘出现又隐藏的问题，因为iOS8的SDK中，苹果提倡使用UIAlertController取代UIAlertView。
#define SYSTEM_VERSION [[UIDevice currentDevice].systemVersion floatValue]
if (SYSTEM_VERSION >= 8.0) {
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil message:@"提示文字" preferredStyle:UIAlertControllerStyleAlert];
UIAlertAction *okAction = [UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
[self.navigationController popToViewController:viewController animated:YES];
}];
[alertController addAction:okAction];
[self presentViewController:alertController animated:YES completion:nil];
} else {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"" message:@"提示文字" delegate:self cancelButtonTitle:@"确定" otherButtonTitles: nil];
[alertView show];
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- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
[self.navigationController popToViewController:viewController animated:YES];
}
