Question

I am using picker view in my application, I am selecting the object but object is not showing on the label,
Please help me

pragma mark- PICKER_VIEW_Delegate_Methods ----------------->>>>



- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView

{

    return 1;

}
// The number of rows of data

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component

{

    if(pickerView == countryPicker)

    {
        return [arrayCountry count];
    }

    if(pickerView == statePicker)

    {
        return [stateArray count];
    }
    else return 5;
}
// The data to return for the row and component (column) that's being passed in

- (NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component

{
    if(pickerView == countryPicker)
    {
        return [arrayCountry objectAtIndex:row];
    }
    if(pickerView == statePicker)

    {
        return  [stateArray objectAtIndex:row];
    }

    return @"";
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

{
    if(pickerView == countryPicker)

    {

        countryLabel.text = countryArray[row];

        countryPicker.hidden = YES;
        NSLog(@"statelabel %@",countryLabel.text);
    }

    if(pickerView == statePicker)

    {
        [stateLabel setText:[stateArray objectAtIndex:row]];
        statePicker.hidden = YES;
    }
}

- (IBAction)countryList:(id)sender
{
    countryPicker.hidden = false;
    [countryPicker reloadAllComponents];

}

- (IBAction)stateList:(id)sender
{
    stateArray = [DictStates valueForKeyPath:countryStr];
    statePicker.hidden = false;
    stateTable.hidden = FALSE;

    [statePicker reloadAllComponents];
}

- (void)getCountryStatesList

{

    NSURLSession *session = [NSURLSession sharedSession];

    NSURLSessionDataTask *dataTask = [session dataTaskWithURL:[NSURL URLWithString:@"http://dev-demo.info.bh-in-15.webhostbox.net/dv/nationalblack/api/countrystate"] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {

        NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

        NSLog(@"List : %@", json);
        dispatch_async(dispatch_get_main_queue(), ^{
            [self parseCountryStates:json];
        });

    }];
    [dataTask resume];

}
- (void)parseCountryStates:(NSDictionary *)json
{

    NSArray *listing = [json objectForKey:@"listing"];

    arrayCountry = [[NSSet setWithArray:[listing valueForKey:@"country"]] allObjects];

    NSArray *states;

    NSMutableDictionary *tempStates = [NSMutableDictionary new];

    for (NSString *countryName in arrayCountry) {

        NSPredicate *predicateString = [NSPredicate predicateWithFormat:@"%K contains[cd] %@", @"country", countryName];

        NSLog(@"predicate %@",predicateString);

        states = [NSMutableArray arrayWithArray:[listing filteredArrayUsingPredicate:predicateString]];

        [tempStates setObject:states forKey:countryName];

    }
    DictStates = tempStates;
}


now country is selected but now when i click on state button it creashed
i am sharing my crash log:

>     -[__NSCFDictionary length]: unrecognized selector sent to instance 0x7f98c9683220
>     2016-06-13 11:30:54.912 [1745:52321] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason:
> '-[__NSCFDictionary length]: unrecognized selector sent to instance
> 0x7f98c9683220'
>     *** First throw call stack:

Answer 1

Replace Your method with

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

{
    if(pickerView == countryPicker)
    {
        countryLabel.text = arrayCountry[row];
        countryPicker.hidden = YES;
        NSLog(@"statelabel %@",countryLabel.text);
    }
    if(pickerView == statePicker)
    {
        [stateLabel setText:[stateArray objectAtIndex:row]];
        statePicker.hidden = YES;
    }
}

Will solve your problem  :)

未在标签上的选择器视图中显示所选对象

1 个答案: