iOS 去除字符串的空格和换行符

1.去除首尾空格：

NSString * content = [textView.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

2.去除首尾空格和换行：

NSString *content = [textView.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];