UIPickerView setup in Xcode?

Question

Hello everyone! I have been working hard lately to understand some of the properties and methods behind some of Xcode's most efficient methods to display friendly user options. Although I have not seen many in today's modern apps, I think the UIPickerView delivers a intuitive way to select a option from several options, with the ability to see them as you scroll.

Here is what I used for the implementation of the main view controller:

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    //Set the values for the UIPickerView.
    self.items = @[@"Multiply", @"Divide", @"Subtract", @"Add", @"Square"];

    //Set the data source and delegate for the UIPickerView.
    [self.picker setDataSource:self];
    [self.picker setDelegate:self];
}

- (IBAction)calculateButtonPressed:(id)sender {

    //Set the string value to be the selected calculation type in the UIPickerView.
    NSString *calculationType = [self.items objectAtIndex:[self.picker selectedRowInComponent:0]];

    //We will store the answer in a double.
    float answer = 0;

    //Determine the type of calculation by the selected type, and do that calculation.
    if ([calculationType isEqualToString:@"Multiply"]) {

    //If the type is multiply, simply multiply the text fields text in the form of a floatValue.
        answer = [self.textFieldInputOne.text floatValue] * [self.textFieldInputTwo.text floatValue];
    }

    if ([calculationType isEqualToString:@"Divide"]) {

    //If the type is divide, simply divide the text fields text in the form of a floatValue.
        answer = [self.textFieldInputOne.text floatValue] / [self.textFieldInputTwo.text floatValue];
    }

    if ([calculationType isEqualToString:@"Subtract"]) {

    //If the type is subtract, simply subract the text fields text in the form of a floatValue.    
        answer = [self.textFieldInputOne.text floatValue] - [self.textFieldInputTwo.text floatValue];
    }

    if ([calculationType isEqualToString:@"Add"]) {

    //If the type is add, simply add the text fields text in the form of a floatValue.
        answer = [self.textFieldInputOne.text floatValue] + [self.textFieldInputTwo.text floatValue];
    }

    if ([calculationType isEqualToString:@"Square"]) {

    //If the type is square, simply square the text fields text in the form of a floatValue.
        answer = [self.textFieldInputOne.text floatValue] * [self.textFieldInputOne.text floatValue];
    }

    //Set the answer text to the answer.
    self.answerTextField.text = [NSString stringWithFormat:@"%f", answer];
}


#pragma mark - UIPickerView methods
// The number of columns of data
- (long)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

// The number of rows of data
- (long)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return [self.items count];
}

// 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
{
    return [self.items objectAtIndex:row];
}

@end

In the scene view, I have two text fields that are used by the user to input numbers to be calculated in some way. I then use the title of the row at the index of 0 to get the currently selected calculation type to perform that calculation. Under the two text fields for input I use a button to calculate the values within the fields. I have the calculateButtonPressed method assigned as an IBAction. Please note that the Square calculation just multiplies the first text fields float value by the first text fields float value. Finally, I assign the value to the answerTextField, a blank and noneditable text field that will show the answer after a calculation has been performed. Please let me know if you see anything wrong with the code that I have wrote or any changes that can improve performance, I always try to perform calculations in house rather than waste memory for them to be temporarily stored for simple things like in this case a calculation.

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landonferrier

landonferrier

UIPickerView setup in Xcode?