搜索并找到一个短语并得到它之前和之后的两个词

Question

我正在使用以下代码在数组中搜索在 UISearchBar 中键入的短语，然后将找到该短语的索引的内容添加到将显示在 [=15 中的数组中=] 查看。

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)enteredSearchText{


    if ([enteredSearchText length] == 0) {

        [wholeTextOfDoaasLive removeAllObjects]; //wholeTextOfDoaasLive is an NSMutableArray

    }
    else{

        [wholeTextOfDoaasLive removeAllObjects];

        for (NSString * string in AllWholeText) {//AllWholeText is an NSMutableArray

            NSRange r = [string rangeOfString:enteredSearchText options:NSCaseInsensitiveSearch]; 

            if (r.location != NSNotFound){

                [wholeTextOfDoaasLive addObject:string];
            }
        }
    }

    [_searchResultsTable reloadData];
}

但是，AllWholeText 数组的每个索引都包含大量文本，我不想将整个对象（在其中找到搜索短语）添加到 wholeTextOfDoaasLive 数组中。相反，我只想将找到的短语加上它前后的两个词添加到我的 wholeTextOfDoaasLive 数组中。我该怎么做？

Answer 1

所以我写了这段代码，它只是将搜索到的短语放入上下文中，如果它接近段落的末尾（数组索引内的段落），那么它会显示 "few"在表格视图单元格中它之前的单词，如果它不接近尾声那么"few"单词会显示在它之后。

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)enteredSearchText{

    if ([enteredSearchText length] == 0) {

        [wholeTextOfDoaasLive removeAllObjects];

    }
    else{

        [wholeTextOfDoaasLive removeAllObjects];

        for (NSString * string in AllWholeText) { //create string that holds the value in that index

            NSRange r = [string rangeOfString:enteredSearchText options:NSCaseInsensitiveSearch]; 

            NSUInteger indexOfFoundString = r.location;
            NSUInteger numberOfAvailableCharactersAfterPhrase = string.length - (indexOfFoundString + 1 );

            NSUInteger takeCharacters = 50; //number of characters that will show in tableview cell
            foundStringIsAtTheEnd  =NO;

            /// START: eliminate the "out of bounds" error ///
            // if the searched phrase is at the end of the text and you ask for 50 characters after it, the app to crash. So here we check if the searched phrase is the near the end or if it's far away from the end. A) if it's close to the end then show words before it. B) if it's far from the end then show words after it.

            if (numberOfAvailableCharactersAfterPhrase < 50) {
                takeCharacters = 40;

                if (numberOfAvailableCharactersAfterPhrase < 40) {
                     takeCharacters = 30;

                    if (numberOfAvailableCharactersAfterPhrase < 30) {
                        takeCharacters = 20;

                        if (numberOfAvailableCharactersAfterPhrase < 20) { //there is less than 20 characters after the searched phrase

                            takeCharacters = numberOfAvailableCharactersAfterPhrase+30;
                            foundStringIsAtTheEnd  =YES;

                        }

                    }
                }
            }
            /// END: eliminate the "out of bounds" error ///

            if (indexOfFoundString != NSNotFound){

                NSString *tableViewString;

                if (foundStringIsAtTheEnd == YES) {

                    indexOfFoundString -= 30; //to show few words before the searched phrase

                    tableViewString = [string substringWithRange:NSMakeRange(indexOfFoundString, takeCharacters)];

                    /// START: remove cropped words, we want only full words ///
                    NSArray *arrayStoredText = [tableViewString componentsSeparatedByString:@" "];
                    NSMutableArray *myMutable = [[NSMutableArray alloc]initWithArray:arrayStoredText];
                    [myMutable removeObjectAtIndex:0]; //cuz maybe it's a cropped word
                    tableViewString = @"";
                    tableViewString = [myMutable componentsJoinedByString:@" "];
                    /// END: remove cropped words, we want only full words ///


                }
                else{ //if searched phrase is far from the end

                    tableViewString = [string substringWithRange:NSMakeRange(indexOfFoundString, takeCharacters)];

                    NSArray *arrayStoredText = [tableViewString componentsSeparatedByString:@" "];
                    NSMutableArray *myMutable = [[NSMutableArray alloc]initWithArray:arrayStoredText];
                    [myMutable removeLastObject]; //cuz maybe it's a cropped word
                    tableViewString = @"";
                    tableViewString = [myMutable componentsJoinedByString:@" "];

                }

                [wholeTextOfDoaasLiveArray addObject:tableViewString];
            }
        }
    }

    [_searchResultsTable reloadData];
}

它并不完全符合我最初的要求（两个词而不是 "few"），但我认为这对用户来说更好，因为这样我可以确保在短语之前显示的文本量tableview 的每个单元格中的内容大致相同（不过可以使其更准确）。

搜索并找到一个短语并得到它之前和之后的两个词

search & find a phrase and get two words that are before it and after it

nsstring

nsarray

uisearchbar

nsrange