iosobjective-cuipickerviewuipickerviewdatasource

set a component of UIPickerView as a separator


I created a decimal number UIPickerView. I want the second component which is just a constant dot string (.) became as a separator, I mean :

1) It doesn't move

2) Its width is smaller than other components

3) Its color is different in comparison with other components

enter image description here

Here is the code:

#pragma mark - UIPickerView : Datasource Protocol
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    return 3;
}

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {    if(component == 2)
        return 10;
    if(component == 1)
        return 1;
    else
        return 1000;
}

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    if(component == 1)
        return @".";
    else
        return [NSString stringWithFormat:@"%ld", (long)row];

}

How can I do this?


Solution

  • You can take a UILable and set the text as "." (i.e Dot), add the label in the picker view. Then take 3 components in the relevant delegate and for second component return nil.

    Here is the Code :

    In your designing method, I did it in viewDidLoad

    myPickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 200, 320, 200)];
    myPickerView.delegate = self;
    myPickerView.showsSelectionIndicator = YES;
    [self.view addSubview:myPickerView];
    
    label = [[UILabel alloc] initWithFrame:CGRectMake(145, 76, 36, 36)];
    label.font = [UIFont boldSystemFontOfSize:40];
    label.layer.cornerRadius = 18.0;
    label.layer.masksToBounds = YES;
    label.text = @".";
    [label setTextColor:[UIColor darkGrayColor]];
    label.backgroundColor = [UIColor clearColor];
    label.textAlignment = NSTextAlignmentCenter;
    label.shadowColor = [UIColor whiteColor];
    label.shadowOffset = CGSizeMake (0,1);
    [myPickerView addSubview:label];
    

    Then in the delegate would be like this

    - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
    {
        return 3;
    }
    
    - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
    {
        if (component ==0) {
            return self.arrItemsTop.count;
        }else if (component == 1){
            return 0;
        }else
            return self.arrItemsOther.count;
    
    }
    - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    
        if (component == 0) {
            return self.arrItemsTop[row];
        }
        else if (component == 1){
            return nil;
        }
        else{
            return self.arrItemsOther[row];
        }
    }
    

    NB : arrItemsTop is the array holding left side values and arrItemsOthers is the array holding right side value

    OutPut :

    enter image description here

    Hope it helps ..

    Happy coding .