为什么即使在设置委托协议后也没有调用UIPickerView委托方法？

Question

`我正在创建一个UIPickerView,它不会从数组中获取数据,因为没有调用委托方法.我设置了UIPickerviewdelegate和datasource但是它仍然没有工作.可能是没有调用委托方法的原因?????如果有人知道它请告诉我.谢谢你.

picker.delegate=self;
picker.dataSource=self;



arrayOfState = [[NSMutableArray alloc] init];
[self.arrayOfState addObject:@"Assam"];
[arrayOfState addObject:@"Andhra Pradesh"];
[arrayOfState addObject:@"Madhya Pradesh"];
[arrayOfState addObject:@"West Bengal"];
[self.arrayOfState addObject:@"Orissa"];    
[self.arrayOfState addObject:@"Meghalaya"];
[arrayOfState addObject:@"Tripura"];
[arrayOfState addObject:@"Arunachal Pradesh"];  
[arrayOfState addObject:@"Jammu and Kashmir"];  

picker=[[UIPickerView alloc] initWithFrame:CGRectMake(0.0f,100.0f,40.0f,120.0f)];
picker.showsSelectionIndicator=YES;

Answer 1

试试这个,

- (void)viewDidLoad
{

    [super viewDidLoad];
arrayOfState = [[NSMutableArray alloc] init];
[self.arrayOfState addObject:@"Assam"];
[arrayOfState addObject:@"Andhra Pradesh"];
[arrayOfState addObject:@"Madhya Pradesh"];
[arrayOfState addObject:@"West Bengal"];
[self.arrayOfState addObject:@"Orissa"];    
[self.arrayOfState addObject:@"Meghalaya"];
[arrayOfState addObject:@"Tripura"];
[arrayOfState addObject:@"Arunachal Pradesh"];  
[arrayOfState addObject:@"Jammu and Kashmir"];

picker=[[UIPickerView alloc] initWithFrame:CGRectMake(0.0f,100.0f,40.0f,120.0f)];
picker.delegate=self;
picker.dataSource=self;
picker.showsSelectionIndicator=YES;
[self.view addSubView:picker];
}

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

// Total rows in our component.
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return [arrayOfState count];
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {

        NSString *title;
        title=[arrayOfState objectAtIndex:row];  
        return title; 
    }


- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
}