Question

代码工作正常但是当我为特定字母添加多个值时，它会重复出现。如果该字母表有单个值，则数据显示正确 - 我哪里出错了？

    - (void)viewDidLoad {
    [super viewDidLoad];

    PeopleModal *dislist = [[PeopleModal alloc]init];
    [dislist getAll];

    personarray = [[NSMutableArray alloc]init];
    [personarray addObjectsFromArray:dislist.Peoplelistarray];
    //short the personarray value:
    NSSortDescriptor *asortDescriptor;
    asortDescriptor=[NSSortDescriptor sortDescriptorWithKey:@"FirstName" ascending:YES selector:@selector(caseInsensitiveCompare:)];

    NSArray *sortDescriptors=[NSArray arrayWithObject:asortDescriptor];
    [self.personarray sortUsingDescriptors:sortDescriptors];

    //---create the index---
    Frstname = [[NSMutableArray alloc] init];

        //check
    NSMutableArray *tempArray = [[NSMutableArray alloc] init];
    for (NSDictionary *row in personarray) {
        [tempArray addObject:[row valueForKey:@"FirstName"]];

        for (int i=0; i<[tempArray count]-1; i++){
            char alphabet = [[tempArray objectAtIndex:i] characterAtIndex:0];
            NSString *uniChar = [NSString stringWithFormat:@"%C", alphabet];
            if (![Frstname containsObject:uniChar]){  
                [Frstname addObject:uniChar];           
            }
        }

    }

}


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.

    return [Frstname count];

}

//---set the title for each section---
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {

    return [Frstname objectAtIndex:section];

}

//---set the index for the table---
- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {

        return Frstname;
}



- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    if (isSearchOn) {
        return [searchResult count];
    } else{
//return personarray.count;
    //---get the letter in each section; e.g., A, B, C, etc.---
    NSString *alphabet = [Frstname objectAtIndex:section];
    //---get all FirstName beginning with the letter---beginswith
    NSPredicate *predicate =
    [NSPredicate predicateWithFormat:@"SELF.FirstName beginswith[c] %@", alphabet];
    NSArray *Names = [personarray  filteredArrayUsingPredicate:predicate];
    //---return the number of Names beginning with the letter---
    return [Names count];
    }

}



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [Mytableview dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
    }
    if (isSearchOn) {
        NSString *cellValue = [searchResult objectAtIndex:indexPath.row];
        cell.textLabel.text = cellValue;
    }
    else {

    //---get the letter in the current section---
    NSString* alphabet = [Frstname objectAtIndex:[indexPath section]];
    //---get all states beginning with the letter---
    NSPredicate *predicate =
        [NSPredicate predicateWithFormat:@"SELF.FirstName beginswith[c] %@", alphabet];
    //[NSPredicate predicateWithFormat:@"SELF beginswith[c] %@", alphabet];
    //NSArray *Names = [[personarray valueForKey:@"FirstName"] filteredArrayUsingPredicate:predicate];
        NSArray *Names = [personarray  filteredArrayUsingPredicate:predicate];
    //NSArray *lastNames = [[personarray valueForKey:@"LastName"] filteredArrayUsingPredicate:predicate];
    if ([Names count]>0) {
        //---extract the relevant firstname from the Names object---


        PeopleModal *locallist = [Names objectAtIndex:indexPath.row];

        cell.textLabel.text = locallist.FirstName;
        cell.detailTextLabel.text=locallist.LastName;           
    }   

    }


    return cell;





}

Answer 1

是的，你正在使用containsObject，并且总是会返回false，因为该对象的id是一个新的NSString，所以你的代码在Array中添加了相同的NSString值。尝试这样的事情：

NSArray *duplicates = [Frstname filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"%C", alphabet]];
if ([duplicates count] == 0) {
    [Frstname addObject:uniChar]
}

Answer 2

你调试你的代码?? 由于这些行

，你得到重复的值

  for (int i=0; i<[tempArray count]-1; i++){
        char alphabet = [[tempArray objectAtIndex:i] characterAtIndex:0];
        NSString *uniChar = [NSString stringWithFormat:@"%C", alphabet];
        if (![Frstname containsObject:uniChar]){  
            [Frstname addObject:uniChar];

        }

这里你正在另一个for循环运行一个for循环。所以每次迭代都会调用它。而不是for循环使用

  char alphabet = [[[row valueForKey:@"FirstName"] characterAtIndex:0];
    NSString *uniChar = [NSString stringWithFormat:@"%C", alphabet];
    if (![Frstname containsObject:uniChar]){  
        [Frstname addObject:uniChar];

我希望你正在编写代码以获得独特的第一个字符......

Answer 3

假设您尝试从Frstname数组中的firstname插入所有非重复字符，请更改：

    //check
NSMutableArray *tempArray = [[NSMutableArray alloc] init];
for (NSDictionary *row in personarray) {
    [tempArray addObject:[row valueForKey:@"FirstName"]];

    for (int i=0; i<[tempArray count]-1; i++){
        char alphabet = [[tempArray objectAtIndex:i] characterAtIndex:0];
        NSString *uniChar = [NSString stringWithFormat:@"%C", alphabet];
        if (![Frstname containsObject:uniChar]){  
            [Frstname addObject:uniChar];
        }
    }

}

为此：

    //check
NSMutableArray *tempArray = [[NSMutableArray alloc] init];
for (NSDictionary *row in personarray) {
    [tempArray addObject:[row valueForKey:@"FirstName"]];

    for (int i=0; i<[tempArray count]-1; i++){
        char alphabet = [[tempArray objectAtIndex:i] characterAtIndex:0];
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF beginswith[c] '%c'", alphabet];
        NSArray *duplicates = [Frstname filteredArrayUsingPredicate:predicate];
        if ([duplicates count] == 0) {
            [Frstname addObject:uniChar];
        }
    }
 }

在iphone的表视图中，排序的值未正确显示

3 个答案: