将特殊字符从iPhone传递到PHP脚本的解决方案（SQL数据库）

Question

OK, after much research, and help with stackoverflow users, I've narrowed down how to fix my problem. Most special characters work, except the ampersand.

So, how can I implement the following code twice? I want to do this

[[tvQ.text stringByReplacingOccurrencesOfString:@"&" withString:@"and"] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]

and

[[tvQ.text stringByReplacingOccurrencesOfString:@"
" withString:@" "] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]

for the same NSString

- (void) doPost:(NSString *)sport {
NSUserDefaults *p = [NSUserDefaults standardUserDefaults];

NSString* string1 = [[p valueForKey:@"user"] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
NSString* string2 = [[p valueForKey:@"pass"] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
NSString* string3 = [[[tvQ.text stringByReplacingOccurrencesOfString:@"
" withString:@" "] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
NSString* string4 = [[tvQ.text stringByReplacingOccurrencesOfString:@"&" withString:@"and"] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
NSString* urlString = [NSString stringWithFormat:@"http://website.com/phpscript.php?user=%@&pass=%@&cat=%@&sub=%@&body=%@",string1,string2,sport,@"",string3,string4];
id val1 = [NSString stringWithContentsOfURL:[NSURL URLWithString:urlString]];
[p setObject:val1 forKey:@"q"];

I'm not sure what I'm doing wrong here so that it respects both arguments defined in string 3 and string4.

Answer 1

Just nest the method that transforms the string:

[[[tvQ.text stringByReplacingOccurrencesOfString:@"&" withString:@"and"] stringByReplacingOccurrencesOfString:@"
" withString:@" "] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]

Now the string has all '&' replaced by "and", AND all " " replaced by " ", AND it has been processed through stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding to make it safe to pass as a web query.

But remember the problem the last question showed - don't nest too deeply, or it can get very hard to read what you wrote when you later go back to it.