numberofSectionInTablesView/NumberofRowsInsection

问题:

I am having trouble returning the numberofSections/numberofRows. I have a dictionary full of data

-(void)setUpContacts{
//set up the contacts
NSString *string = @"ABCDEFGHIJKLMNOPQRSTUVWXYZ";

letterArray = [[NSMutableDictionary alloc]init];

Contacts *contact = [[Contacts alloc]init];
contactNumbers = [contact phoneNumbers];

for (NSDictionary* info in contactNumbers) {
    firstLetter = [info objectForKey:@"lastName"];
    index = @"_";
    if([firstLetter length] > 0){
        firstLetter =[firstLetter substringToIndex:1];
        firstLetter= [firstLetter capitalizedString];
        NSRange range = [string rangeOfString:firstLetter];
        if(range.length >= 0){
            index= firstLetter;
        }
    }
    if(![letterArray objectForKey:index]){

        [letterArray setValue:[NSMutableArray array] forKey:index];
    }
    [[letterArray objectForKey:index] addObject:info];

}
NSLog(@"%@",letterArray);}

and it NSLogs with this

C =     (
            {
        firstName = Alex;
        kind = Mobile;
        lastName = Chang;
        name = "Alex Chang (Mobile)";
        number = "[phone]";
    },
            {
        firstName = YuYu;
        kind = Mobile;
        lastName = Chen;
        name = "YuYu Chen (Mobile)";
        number = "[phone]";
    },
            {
        firstName = Chris;
        kind = Mobile;
        lastName = Choi;
        name = "Chris Choi (Mobile)";
        number = "[phone]";
    },
            {
        firstName = Kevin;
        kind = Mobile;
        lastName = Chung;
        name = "Kevin Chung (Mobile)";
        number = "1 [phone]";
    }
);
H =     (
            {
        firstName = Danny;
        kind = Mobile;
        lastName = Huang;
        name = "Danny Huang (Mobile)";
        number = "[phone]";
    },
            {
        firstName = Ice;
        kind = Mobile;
        lastName = Huang;
        name = "Ice Huang (Mobile)";
        number = "[phone]";
    }
);
K =     (
            {
        firstName = Will;
        kind = Mobile;
        lastName = King;
        name = "Will King (Mobile)";
        number = "[phone]";
    }
);
L =     (
            {
        firstName = "";
        kind = iPhone;
        lastName = LastName;
        name = " LastName (iPhone)";
        number = "[phone]";
    },
            {
        firstName = david;
        kind = Mobile;
        lastName = lub;
        name = "david lub (Mobile)";
        number = "[phone]";
    }
);

for the -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView; method how do i retrieve the number of sections for index;

and for the -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section; method, how do i retreive the number of rows in the section?

EDIT

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
NSArray *array = [letterArray mutableCopy];
return [[array objectAtIndex:section]count];}

and it gives me this error: -[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance 0x8434cc0

Thank you in advance

回答1:

for -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView you should do something like this:

return [letterArray count];

for -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section you should do something like this:

NSArray *array = letterArray;
return [[array objectAtIndex:section] count];

EDIT Try this:

-(NSArray *)getLetterArrayCount {
    NSMutableArray *countArray = [[NSMutableArray alloc] init];
    NSNumber *subCount;

    for (id key_main in letterArray) {
        subCount = 0;

        for (id key_sub in [letterArray objectForKey:key_main]) {
            subCount = [NSNumber numberWithInt:[subCount intValue] + 1];
        }

        [countArray addObject:subCount];
    }
    return countArray;
}

You should call it once and save it to a class variable and call it like this for sections:

[countArray count];

And for the rows in a section like this:

[[countArray objectAtIndex:section] intValue];

回答2:

letterArray = [[NSMutableDictionary alloc]init];
indexArray = [[NSMutableArray alloc] init];



[letterArray setValue:[NSMutableArray array] forKey:index];
[indexArray addObject:index];

for -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView :

return [letterArray count];

for -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section :

return [[letterArray objectForKey:[indexArray objectAtIndex:section]] count];

I think it will be helpful to you.

回答3:

in ur question the letterarray is an NSDictionary. it wont show You the objectAtIndex option. try to change the NSMutableDictionary into NSMutableArray. then you will get the option.

and

return(letterarray.count)

NSMutableArray * arr = [[NSMutableArray alloc]init];
for (NSArray *ar in letterarray){
            [arr addObject:ar];
}

Return this arr.count

i am Learning.,.,.