- (NSString *)stringByAddingPercentEscapesUsingEncoding:(NSStringEncoding)encoding
- (NSString *)stringByReplacingPercentEscapesUsingEncoding:(NSStringEncoding)encoding

NSString* string1 = @"https://www.cloudsafe.com/文件夹";

NSString* string2 = [string1 stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString* string3 = [string2 stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSString* string4 = [string2 stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString* string5 = [string3 stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSString* string6 = [string4 stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString* string7 = [string5 stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

string1:https://www.cloudsafe.com/文件夹

string2:https://www.cloudsafe.com/%E6%96%87%E4%BB%B6%E5%A4%B9
string3:https://www.cloudsafe.com/%25E6%2596%2587%25E4%25BB%25B6%25E5%25A4%25B9

string4:https://www.cloudsafe.com/文件夹
string5:https://www.cloudsafe.com/%E6%96%87%E4%BB%B6%E5%A4%B9

string6:https://www.cloudsafe.com/文件夹
string7:https://www.cloudsafe.com/文件夹

NSMutableString *address = [[NSMutableString stringWithString:SetNiChengStringWithoutUserNameAndNiCheng] mutableCopy];
  address = [[address stringByAppendingString:app.name] mutableCopy];
  address = [[address stringByAppendingString:@"/"] mutableCopy];
  address = [[address stringByAppendingString:_nameTextField.text] mutableCopy];
  address = [[address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] mutableCopy];
  address = [[address stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] mutableCopy];