IOS单位转换器需要双选择器和使用两个 NSMutible 数组的帮助

Question

我正在制作一个 iOS 单位转换器，需要帮助以正确的方式制作双重选择器。我知道两个如何在组件数量部分返回 2。我将在下面发布我的代码示例，非常感谢所有帮助和批评。

           [theArray1 addObject:@"Feet-Inch"];
           [theArray1 addObject:@"Feet-Milimeter"];
           [theArray1 addObject:@"Feet-Centimeter"];
           [theArray1 addObject:@"Feet-Meter"];
           [theArray1 addObject:@"Inch-Milimeter"];
           [theArray1 addObject:@"Inch-Centimeter"];
           [theArray1 addObject:@"Inch-Meter"];


           [thePicker selectRow:0 inComponent:0 animated:YES];



           }

      -(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
       return 1 ;

          }
      -(NSInteger)pickerView:(UIPickerView *)
      pickerViewnumberOfRowsInComponent:
     (NSInteger)component{  return [theArray1 count];

          }





            -(NSString*) pickerView:(UIPickerView *)
           pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)
        component{
         return [theArray1 objectAtIndex:row];

        }

Answer 1

只需借助组件参数在两个数组之间切换即可。

像这样：

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {  
    if (component == 0) {
        return [array1 count];
    }
    else if (component == 1) {
        return [array2 count];
    }
    return 0;
}

用相同的模式重写其他委托方法。