Monday, May 20, 2013

NSString NSWidthInsensitiveSearch example ios

Search and Comparison Options - NSWidthInsensitiveSearch

These values represent the options available to many of the string classes’ search and comparison methods.
enum {
   NSCaseInsensitiveSearch = 1,
   NSLiteralSearch = 2,
   NSBackwardsSearch = 4,
   NSAnchoredSearch = 8,
   NSNumericSearch = 64,
   NSDiacriticInsensitiveSearch = 128,
   NSWidthInsensitiveSearch = 256,
   NSForcedOrderingSearch = 512,
   NSRegularExpressionSearch = 1024
A case-insensitive search.
Exact character-by-character equivalence.
Search from end of source string.[NSString NSWidthInsensitiveSearch]
Search is limited to start (or end, if NSBackwardsSearch) of source string.
Numbers within strings are compared using numeric value, that is, Name2.txt <Name7.txt < Name25.txt.
This option only applies to compare methods, not find.
Search ignores diacritic marks.[NSString NSWidthInsensitiveSearch]
For example, ‘ö’ is equal to ‘o’.
Search ignores width differences in characters that have full-width and half-width forms, as occurs in East Asian character sets.
For example, with this option, the full-width Latin small letter 'a' (Unicode code point U+FF41) is equal to the basic Latin small letter 'a' (Unicode code point U+0061).
Comparisons are forced to return either NSOrderedAscending orNSOrderedDescending if the strings are equivalent but not strictly equal.
This option gives stability when sorting. For example, “aaa” is greater than "AAA” if NSCaseInsensitiveSearch is specified.
The search string is treated as an ICU-compatible regular expression. If set, no other options can apply except NSCaseInsensitiveSearch and NSAnchoredSearch. You can use this option only with the rangeOfString:...methods and stringByReplacingOccurrencesOfString:withString:options:range:.
Discussion of [NSString NSWidthInsensitiveSearch]
See “Searching, Comparing, and Sorting Strings” for details on the effects of these options.

Example of [NSString NSWidthInsensitiveSearch]

- (void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope
    [self.filteredListContent removeAllObjects];
    for (Notice *notice in allNoticeArray)
        if ([scope isEqualToString:@"标题"]) 
            NSComparisonResult result = [notice.title compare:searchText
                                                        range:NSMakeRange(0, [searchText length])];
            if (result == NSOrderedSame)
                [self.filteredListContent addObject:notice];

Example of [NSString NSWidthInsensitiveSearch]
NSString *fold1 = [str1 stringByFoldingWithOptions:NSDiacriticInsensitiveSearch | NSCaseInsensitiveSearch | NSWidthInsensitiveSearch locale:[NSLocale currentLocale]];
NSString *fold2 = [str2 stringByFoldingWithOptions:NSDiacriticInsensitiveSearch | NSCaseInsensitiveSearch | NSWidthInsensitiveSearch locale:[NSLocale currentLocale]];
NSRange range = [fold1 rangeOfString:fold2]; // or other string comparisons
Example of [NSString NSWidthInsensitiveSearch]
static NSInteger comparator(id a, id b, void* context)
    NSInteger options = NSCaseInsensitiveSearch
        | NSNumericSearch              // Numbers are compared using numeric value
        | NSDiacriticInsensitiveSearch // Ignores diacritics (â == á == a)
        | NSWidthInsensitiveSearch;    // Unicode special width is ignored

    return [(NSString*)a compare:b options:options];