How to change color of selected row in UIPickerView

Question

Ok, maybe I\'m missing something really simple and I apologize if that\'s the case, however, I\'ve googled every permutation of the title and have not found! So this is sim

Answer 1

Solved! Declare 2 instance variables: selectedView, and oldView. Then the following code does the trick:

if (self.oldView != nil)
        self.oldView.backgroundColor = [UIColor clearColor];

self.selectedView = [picker viewForRow:row forComponent:kNumberComponent];
        self.selectedView.backgroundColor = [UIColor redColor];
        [self.selectedView setNeedsDisplay];
        self.oldView = self.selectedView;

Answer 2

Normally, I use this method:

I use the custom view for show the row item

-(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{

    UILabel *label = (id)view;

    if (!label)
    {

        label= [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)];
        label.textAlignment = NSTextAlignmentCenter;
        label.textColor = [UIColor whiteColor];
        label.text = _arrayStringPicker[row];

    }  

    return label;

I change color of row selected with:

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

    UILabel *labelSelected = (UILabel*)[pickerView viewForRow:row forComponent:component];
    [labelSelected setTextColor:[UIColor redColor]];

}

Answer 3

// CGRectMake values for the frame we’d like

UIPickerView *myPickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0,0, self.view.bounds.size.width, self.view.bounds.size.height)];

// add the UIPickerView to your viewcontroller [mainView addSubview:myPickerView];

// set the selectionindicator to none myPickerView.showsSelectionIndicator = NO;

// define the image that we would like to use

UIImage *selectorImage = [UIImage imageNamed:@"selectionIndicator.png"];

UIView *customSelector = [[UIImageView alloc] initWithImage:selectorImage];

// set the x and y values to the point on the UIPickerView where you want to place the image

// set the width and height values to the width and height of your image

customSelector.frame = CGRectMake(10,(myPickerView.bounds.size.height / 2) + 16, self.view.bounds.size.width – 10, 47);

// add the custom selectionIndicator also to the same viewcontroller

[mainView addSubview:customSelector];

Answer 4

The correct format for viewForPicker is:

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    UILabel *label = (UILabel*) view;
    if (label == nil)
    {
        label = [[UILabel alloc] init];
    }

    [label setText:@"Whatever"];

    // This part just colorizes everything, since you asked about that.

    [label setTextColor:[UIColor whiteColor]];
    [label setBackgroundColor:[UIColor blackColor]];
    CGSize rowSize = [pickerView rowSizeForComponent:component];
    CGRect labelRect = CGRectMake (0, 0, rowSize.width, rowSize.height);
    [label setFrame:labelRect];

    return label;
}

The problem with the code above is: it colorizes the labels, but not the picker, itself. So, when you roll to one end or the other, there's a blank spot where you can see the white background. Setting [myPicker setBackgroundColor...] doesn't do what one might hope.

Answer 5

It's unclear where you are putting the above code. Is it in -pickerView:viewForRow:forComponent:reusingView:? This is where it should be. Are you sure that you are maintaining a pointer to the label for that particular view? The fact that you are crashing suggests you probably are not. A larger block of code, including where you have put it, would be helpful.

Answer 6

Here's what worked for me:

1. Add a UIView as a subview to your UIPickerView
2. Constrain it to be Y entered with your UIPickerView and the has the same width
3. Give it height equal to the height of what returned in pickerView(_ pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat
4. Make it semi transparent and color it the way you want

*the rest of the solutions (with custom views for row or attributed stringsfor row) were buggy when scrolling fast.