ios11 选取图片或视频照片被导航栏遮挡

解决办法:将导航条的毛玻璃效果去除掉就可以了

 UIImagePickerController *pickerController = [[UIImagePickerController alloc] init];

    pickerController.editing = YES;

    pickerController.delegate = self;

    pickerController.allowsEditing = YES;

//    去除毛玻璃效果

    pickerController.navigationBar.translucent = NO;

    pickerController.sourceType=UIImagePickerControllerSourceTypePhotoLibrary;

    [self presentViewController:pickerController animated:YES completion:nil];