我正在尝试做的事情:
我有一个ViewController
:
@implementation ViewController
@synthesize myPicker;
@synthesize myPickerHelper;
@synthesize label;
#pragma mark - View lifecycle
- (void)viewDidLoad
{
[super viewDidLoad];
myPickerHelper = [[UIPickerViewHelper alloc]initWithUIPickerView:myPicker andNumberOfComponents:4];
[myPickerHelper.valuesForComponent1 addObject:@"TEST1"];
[myPickerHelper.valuesForComponent1 addObject:@"TEST2"];
;
[weightsPicker reloadAllComponents];
[weightsPicker selectRow:0 inComponent:0 animated:YES];
//TODO receive message from picker helper.
//label.text = ... set a listner (like that one in java) or what else
}
}
我有一个PickerViewHelper
:(处理委托(delegate)和数据源问题)
@interface UIPickerViewHelper : NSObject <UIPickerViewDelegate, UIPickerViewDataSource, OnPickerViewChangeDelegate>
@implementation UIPickerViewHelper
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
//TODO send message to controller view.
}
协议(protocol):
@protocol OnPickerViewChangeDelegate
@optional
-(void)onChange:(NSString*)result;
@end
我想要的是在我的 UiPickerViewHelper 类中使用协议(protocol)方法“onChange”,以便我的标签(在我的 ViewController 中)得到通知。 我知道如何在 Java 中解决这个问题,但我不知道如何在 Objective C 中解决这个问题。
问候
最佳答案
UIPickerViewHelper.h
@property (nonatomic, assign) id <OnPickerViewChangeDelegate> delegate
UIPickerViewHelper.m
@synthesize delegate;
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
//TODO send message to controller view.
[self.delegate onChange:[NSString stringWithFormat:@"Selected row %d", row]];
}
ViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
myPickerHelper = [[UIPickerViewHelper alloc]initWithUIPickerView:myPicker andNumberOfComponents:4];
myPickerHelper.delegate = self;
...
}
-(void)onChange:(NSString*)result {
NSLog(@"Here is the result: %@", result);
label.text = result;
}
关于iOS UiPickerView(-Helper) 应发送消息,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15068554/