排序值不正确歌厅显示的tableview在iphone

Question

的代码工作正常，但是当我对一个特定的字母添加一个以上的值，它就会被重复。如果该字母表有单个值，则数据显示正确 - 我哪里错了？

- (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，这将永诺返回false，因为这个对象的id是一个新的NSString让你的代码在阵列添加相同的NSString值。试试这样的：

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

Answer 2

你有没有调试你的代码？ 你正在因为这些线路

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]; 

     } 

在这里你正在运行的重复值在侧环路另一个用于loop.so这将被调用为每一个迭代。 代替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]; 

我希望你正在写的代码，以获得独特的前几个字符...

Answer 3

假设你正试图从一个姓插入所有不重复的字符Frstname阵列，改变该：

//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]; 
     } 
    } 

} 

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]; 
     } 
    } 
}