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POHow can i get UIPickerview to update UILabel automatically
 

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  1. POHow can i get UIPickerview to update UILabel automatically
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    <p>I have a converter app, and i want it to update the label whenever im typing the numbers (that should be converted) into the text field. I want it to update automatically so i dont need to pick the units on the wheel again for it to update. </p> <p><img src="https://i.stack.imgur.com/cF0eR.png" alt="enter image description here"></p> <p><img src="https://i.stack.imgur.com/Q8xLx.png" alt="enter image description here"></p> <p>here is my code:</p> <pre><code>- (void)viewDidLoad { [super viewDidLoad]; { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. _convertFrom = @[@"MTPA", @"MMcf/day", @"Mill.Sm3/day", @"MMBTU", @"Boe/day"]; _convertRates = @[ @1.0f, @133.4246575f, @3.780821918f, @142465.7534f, @23780.8f]; _convertTo = @[@"MTPA", @"MMcf/day", @"Mill.Sm3/day", @"MMBTU", @"Boe/day"]; _convertRates = @[ @1.0f, @133.4246575f, @3.780821918f, @142465.7534f, @23780.8f]; } } </code></pre> <p>shuold i do something here?</p> <pre><code>- (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; </code></pre> <p>}</p> <pre><code>-(IBAction)textFieldReturn:(id)sender { [sender resignFirstResponder]; } -(IBAction)backgroundTouched:(id)sender { [inputText resignFirstResponder]; } #pragma mark - #pragma mark PickerView DataSource - (NSInteger)numberOfComponentsInPickerView: (UIPickerView *)pickerView { return 2; } - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent: (NSInteger)component { if (component == 0) { return [_convertFrom count]; } return [_convertTo count]; } - (NSString *) pickerView: (UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component { if (component == 0) { return [_convertFrom objectAtIndex:row]; } return [_convertTo objectAtIndex:row]; } #pragma mark - #pragma mark PickerView Delegate -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { float convertFrom = [[_convertRates objectAtIndex:[pickerView selectedRowInComponent:0]] floatValue]; float convertTo = [[_convertRates objectAtIndex:[pickerView selectedRowInComponent:1]] floatValue]; float input = [inputText.text floatValue]; float to = convertTo; float from = convertFrom; float convertValue = input; float relative = to / from; float result = relative * convertValue; NSString *convertFromName = [_convertFrom objectAtIndex:[pickerView selectedRowInComponent:0]]; NSString *convertToName = [_convertFrom objectAtIndex:[pickerView selectedRowInComponent:1]]; NSString *resultString = [[NSString alloc]initWithFormat: @" %.4f %@ = %.4f %@",convertValue, convertFromName, result, convertToName]; resultLabel.text = resultString; } </code></pre>
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      1. POHow can i get UIPickerview to update UILabel automatically
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    1. CODo you mean that as you type the numbers you want the conversion calculation to execute? In your screen shot I don't see a UIPickerView so I cannot figure out what you are asking.
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      1. USWalter
    2. CO@Walter I want it to do as you said in the first sentence. Thought that it would be understandable when you could see the label without numbers, and then textfield with numbers. i want it to say 123 = 452, instantly :)
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    3. COAh, then Maddy's answer below is correct. You just need to call your conversion function from the delegate method for the textField. The method you want to use is: - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string you should call your method that does the conversion and then have the delegate method return YES so that the screen will update.
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      1. USWalter
 

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