ios - 一个 ViewController 中的三个 UIPickerView

Question

我有三个 UIPickerView，我在一个 ViewController 中使用它们。它需要彼此独立，因为我需要保存每个结果，但是当我运行它时，它会看到三个 pickerView，当您选择不同的 UIPickerView 时，它们也保存相同的结果。 ViewController.m 文件:

 @interface ViewController (){
 NSArray *_pickerData;
 NSArray *_pickerData2;
 NSArray *_pickerData3;

__weak IBOutlet UITextField *max;
__weak IBOutlet UITextField *m2;
__weak IBOutlet UITextField *m3;
 }
@end

@implementation ViewController


   - (void)viewDidLoad {
     [super viewDidLoad];
 _pickerData = @[@"Apple",@"Avocado",@"Asparagus",@"Grapefruit"];
    _pickerData2 = @[@"Apple",@"Avocado",@"Asparagus",@"Grapefruit"];
    _pickerData3 = @[@"Apple",@"Avocado",@"Asparagus",@"Grapefruit"];
// Do any additional setup after loading the view, typically from a nib.
self.picker.dataSource = self;
self.picker.delegate = self;
self.picker2.dataSource = self;
self.picker2.delegate = self;
self.picker3.dataSource = self;
self.picker3.delegate = self;
}

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
// The number of columns of data
- (int)numberOfComponentsInPickerView:(UIPickerView *)pickerView
 {
return 1;
 }

 // The number of rows of data
 - (int)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
 {
return _pickerData.count;
  }
  - (int)picker2View:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
  {
return _pickerData2.count;
  }
  - (int)picker3View:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
  {
return _pickerData3.count;
  }
 - (NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:           (NSInteger)component                    
   {
   self->max.text = [NSString stringWithFormat:@"%@", _pickerData[row]];

    return _pickerData[row];

    }
   - (NSString*)pickerView2:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent: (NSInteger)component
     {
     self->m2.text = [NSString stringWithFormat:@"%@", _pickerData2[row]];
     return _pickerData2[row];
      }
  - (NSString*)pickerView3:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:   (NSInteger)component
      {
       self->m3.text = [NSString stringWithFormat:@"%@", _pickerData2[row]];
       return _pickerData3[row];
       }
       @end

当我运行它时，三个 PickerView 像 one.ViewController.h 文件一样工作:

       #import <UIKit/UIKit.h>

      @interface ViewController : UIViewController<UIPickerViewDataSource, UIPickerViewDelegate>
      @property (weak, nonatomic) IBOutlet UIPickerView *picker;
      @property (weak, nonatomic) IBOutlet UIPickerView *picker2;
      @property (weak, nonatomic) IBOutlet UIPickerView *picker3;
      @end

Answer 1

被调用的委托(delegate)和数据源方法对于所有选择器 View 都是相同的。不同之处在于传递给该方法的 pickerView 参数。因此，例如，而不是:

- (int)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return _pickerData.count;
}
- (int)picker2View:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return _pickerData2.count;
}
- (int)picker3View:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return _pickerData3.count;
}

你应该:

- (int)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    if (pickerView == self.picker) {
        return _pickerData.count;
    } else if (pickerView == self.picker2) {
        return _pickerData2.count;
    } else if (pickerView == self.picker3) {
        return _pickerData3.count;
    }
}

以此类推所有其他委托(delegate)/数据源方法。