Objective c 动态UIPickerView更新

我有两个UIPickerView的问题

第一个名为pickerParent的采摘者选择一种食物。 然后，第二个名为pickerChild的采摘者显示了这些类型食物的列表

问题是，如果pickerChild尝试选择其中一个项目，pickerChild将更新自身以匹配pickerParent列表中的相应项目。（例如：如果您在pickerParent上选择肉类，pickerChild将显示“姜牛肉、柠檬鸡、盐椒排骨和糖醋猪肉”。如果您在pickerChild列表中选择糖醋猪肉，作为列表中的第四项，它将获得蔬菜属性，并且仅显示“什锦蔬菜”）

有人能帮我让pickerChild不更新自己吗

我的代码如下

#import "MasterViewController.h"

#import "DetailViewController.h"

@interface MainPage () {
   NSMutableArray *_objects;
}
@end

@implementation MainPage
@synthesize pickerChild;
@synthesize pickerParent;
@synthesize image_view;

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return ( pickerView == pickerParent ? 1 : 1 );
}

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    NSArray *values = ( pickerView == pickerParent ? topics : items );
    return [values count];
}

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    NSArray *values = ( pickerView == pickerParent ? topics : items );
    return [values objectAtIndex: row];
}

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component{
    if ([[topics objectAtIndex:row] isEqual:@"Noodles"]) {
       items = noodle;
    } else if ([[topics objectAtIndex:row] isEqual:@"Rice"]) 
    {
       items = rice;
    } else if ([[topics objectAtIndex:row] isEqual:@"Meat"]) 
    {
        items = meat;
    } else if ([[topics objectAtIndex:row] isEqual:@"Vegetables"]) 
    {
        items = vegatable;
    } else if ([[topics objectAtIndex:row] isEqual:@"Favorites"]) 
    {
        items = favorite;
    }
[pickerChild reloadAllComponents];

}

- (void)awakeFromNib
{
    [super awakeFromNib];
}

- (void)viewDidLoad
{
    topics = [[NSMutableArray alloc] init];
    [topics addObject:@"Noodles"];
    [topics addObject:@"Rice"];
    [topics addObject:@"Meat"];
    [topics addObject:@"Vegetables"];
    [topics addObject:@"Favorites"];

    noodle = [[NSMutableArray alloc] init];
    [noodle addObject:@"Fried Noodles"];
    [noodle addObject:@"Shanghai Noodles"];

    meat = [[NSMutableArray alloc] init];
    [meat addObject:@"Ginger Beef"];
    [meat addObject:@"Lemon Chicken"];
    [meat addObject:@"Salt & Pepper Ribs"];
    [meat addObject:@"Sweet & Sour Pork"];

    vegatable = [[NSMutableArray alloc] init];
    [vegatable addObject:@"Assorted Vegetables"];

    rice = [[NSMutableArray alloc] init];
   [rice addObject:@"Fried Rice"];

    items = noodle;

    [super viewDidLoad];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}
@end

---

您的

didSelectRow..

delegate方法不区分这两个选择器，因此您的子选择器将重新加载您更改的任何选择器。仅当父选择器中的选择已更改时，才需要重新加载子选择器

因此，将您当前拥有的代码包装到：

 if (pickerView == parentPicker)

你应该没事的