u014607644的专栏

今天在使用UIImagePickerController拍照换头像的时候， Snapshotting a view that has not been rendered results in an empty snapshot. Ensure your view has been rendered at least once before snapshotting or snapshot aft

将字符串中开头和结尾的空格去掉： - (NSString *)stringByTrimmingCharactersInSet:(NSCharacterSet *)set; 举例说明： NSString *oldString = @"   MacBook Pro   "; NSString *newString = [oldString stringByTrimm