如何恢复我的选择器值

Question

华氏度是 NSObject，WakingTemperature 是 UIViewController。我正在将选择器值从华氏温度更新为 WakingTemperature（基本上是两个用于切换华氏温度和摄氏温度的 nsobject，我放置了华氏温度的代码）。

现在我有问题恢复我的选择器值但没有发生。这是我尝试过的 在可更新中，请帮助我。

@interface FertilityAppAppDelegate
----------------------------------
        NSInteger pickerRowCompzero;
        NSInteger pickerRowCompone;
        float valueConv;

        @property (nonatomic) NSInteger pickerRowCompzero;
        @property (nonatomic) NSInteger pickerRowCompone;
        @property (nonatomic) float valueConv;

@implementation FertilityAppAppDelegate
---------------------------------------
        @synthesize pickerRowCompzero,pickerRowCompone;
        @synthesize valueConv;

@implementation Fahrenheit
--------------------------
   - (id)init 
{        
 /* initialize data-arrays here */

 ArrayofTempIntegerofCelsius = [[NSMutableArray alloc] init];

 [ArrayofTempIntegerofCelsius addObject:@"36"];
 [ArrayofTempIntegerofCelsius addObject:@"37"];
 [ArrayofTempIntegerofCelsius addObject:@"38"];
 [ArrayofTempIntegerofCelsius addObject:@"39"];
 [ArrayofTempIntegerofCelsius addObject:@"40"];
 [ArrayofTempIntegerofCelsius addObject:@"41"];

 ArrayofbothTempfractional = [[NSMutableArray alloc] init];

 [ArrayofbothTempfractional addObject:@".0"];
 [ArrayofbothTempfractional addObject:@".1"];
 [ArrayofbothTempfractional addObject:@".2"];
 [ArrayofbothTempfractional addObject:@".3"];
 [ArrayofbothTempfractional addObject:@".4"];
 [ArrayofbothTempfractional addObject:@".5"];
 [ArrayofbothTempfractional addObject:@".6"];
 [ArrayofbothTempfractional addObject:@".7"];
 [ArrayofbothTempfractional addObject:@".8"];
 [ArrayofbothTempfractional addObject:@".9"];

 Appdelegate = (FertilityAppAppDelegate*)[[UIApplication sharedApplication] delegate];


 return self;             
}



    - (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
    { 
        [self updateLabel];
    }

    -(void) updateLabel
    {
        Appdelegate.pickerRowCompzero=[pickerView selectedRowInComponent:0];
     Appdelegate.pickerRowCompone=[pickerView selectedRowInComponent:1];

     NSString *integer   = [ArrayofTempIntegerofFahrenheit objectAtIndex:Appdelegate.pickerRowCompzero];
     NSString *fraction  = [ArrayofbothTempfractional      objectAtIndex: Appdelegate.pickerRowCompone]; 

     NSString *fahrenheit  = [NSString stringWithFormat:@"%@%@",integer,fraction];
     Appdelegate.valueConv = [fahrenheit floatValue]; 

     label.text=[NSString stringWithFormat:@"%.1f",Appdelegate.valueConv];
     NSLog(@"float:%f ",Appdelegate.valueConv);

edit    // [pickerView reloadAllComponents];
    }

Answer 1

首先，为什么要在 updateLabel 结束时重新加载 pickerview ？

要将选择器初始化为特定值 xxx，您可以使用

[pickerView selectRow:xxx  inComponent:0 animated:FALSE]; // set default values

链接文本

Answer 2

从 updateLabel 中删除

Appdelegate.pickerRowCompzero=[pickerView selectedRowInComponent:0];
Appdelegate.pickerRowCompone=[pickerView selectedRowInComponent:1];

在 didSelectRow 方法中完成的更改

Appdelegate.pickerRowCompzero=[pickerView selectedRowInComponent:0];
Appdelegate.pickerRowCompone= [pickerView selectedRowInComponent:1];