//正则表达式替换两个以上的空格为一个空格
NSError *error = nil;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"\\s{2,}" options:NSRegularExpressionCaseInsensitive error:&error];
NSArray *arr = [regex matchesInString:self.textView.text options:NSMatchingReportCompletion range:NSMakeRange(0, [self.textView.text length])];
arr = [[arr reverseObjectEnumerator] allObjects];
for (NSTextCheckingResult *str in arr) {
self.textView.text = [self.textView.text stringByReplacingCharactersInRange:[str range] withString:@" "]; }
NSLog(@"%@", self.textView.text);