如何从TextField获取十进制值并在Objective C中使用它进行计算

Question

Im really new to objective c and I faced some problems with the Textfields and their values. I have two TextFields in my ViewController. With those TextFields Im trying to get the weight and height of the user and calculate their Body Mass index. I already wrote the code below in android and try to convert it to objective c .

valueWeight = Double.parseDouble(edit_txt_weight.getText().toString());
valueHeight = Double.parseDouble(edit_txt_height.getText().toString());
resulBMI = (valueWeight / (valueHeight * valueHeight)*10000);
txt_vki_resultText.setText(new DecimalFormat("##.##").format(resulBMI)+"");

My Questions are;

1. How do I get the values from the Textfields (Keyboard type is Decimal Pad) and convert them to decimal numbers.

2. How to make the calculations in objective c, I get some problems when I get the values from Textfields with this code

- (IBAction)btnCalculate:(id)sender { NSString *weight = self.editTextKg.text; NSString *height = self.editTextHeight.text; }

Answer 1

- (IBAction)btnCalculate:(id)sender {

   double weight = [ self.editTextKg.text doubleValue] 

   double height = [ self.editTextHeight.text  doubleValue];

   double resulBMI = (valueWeight / (valueHeight * valueHeight)*10000);

   txt_vki_resultText.text = [NSString stringWithFormat:@"%.2f",resulBMI];
}