ios - 按钮项的基础 IBAction 基于其他按钮项的标题

Question

希望这是一个简单的过程。

事情是这样的:我有一个按钮项“选择”，它会打开一个选择器。当用户从选取器中选择某些内容时，“选择”按钮的标题会更改为所选内容，并且选取器会以动画形式消失。现在我已经创建了第二个“搜索”按钮，它将查询 Google Places API，但我需要它不查询 ITS 标题，而是查询 OTHER 按钮的标题。有道理吗？

这是相关代码。我确信这是一个简单的调整，但我是 Objective-C 的新手，所以我仍然在思考事情是如何运作的。

ViewController.m

#import "RendezvousViewController.h"

@interface RendezvousViewController ()

@end

@implementation RendezvousViewController

// returns the number of 'columns' to display.
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

// returns the # of rows in each component..
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return [self.userSelectArray count];
}

-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row   forComponent:(NSInteger)component
{
    return [self.userSelectArray objectAtIndex:row];
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row   inComponent:(NSInteger)component{

    NSLog(@"Selected Row %ld", (long)row);
    switch(row)
    {

        case 0:
            self.userSelection.title = @"Breakfast";
            break;
        case 1:
            self.userSelection.title = @"Brunch";
            break;
        case 2:
            self.userSelection.title = @"Lunch";
            break;
        case 3:
            self.userSelection.title = @"Dinner";
            break;
        case 4:
            self.userSelection.title = @"Bar";
            break;
        case 5:
            self.userSelection.title = @"Late Night Snack";
            break;
    }

}

-(void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    self.userSelectArray  = [[NSArray alloc]         initWithObjects:@"Breakfast",@"Brunch",@"Lunch",@"Dinner",@"Bar",@"Late Night Snack" , nil];

    //Make this controller the delegate for the map view.
    self.mapView.delegate = self;

    // Ensure that you can view your own location in the map view.
    [self.mapView setShowsUserLocation:YES];

    //Instantiate a location object.
    locationManager = [[CLLocationManager alloc] init];

    //Make this controller the delegate for the location manager.
    [locationManager setDelegate:self];

    //Set some parameters for the location object.
    [locationManager setDistanceFilter:kCLDistanceFilterNone];
    [locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
    firstLaunch=YES;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)toolbarButtonPress:(id)sender {
    UIBarButtonItem *button = (UIBarButtonItem *)sender;
    NSString *buttonTitle = [button.title lowercaseString];
    [self queryGooglePlaces:buttonTitle];
    //Use the above title text to build the URL query and get the data from Google.
}

ViewController.m

@interface RendezvousViewController : UIViewController <MKMapViewDelegate, CLLocationManagerDelegate, UIPickerViewDataSource,UIPickerViewDelegate>

{
    CLLocationManager *locationManager;
    CLLocationCoordinate2D currentCentre;
    int currenDist;
    BOOL firstLaunch;
}

@property (strong, nonatomic) IBOutlet MKMapView *mapView;
@property (strong, nonatomic) IBOutlet UIBarButtonItem *userSelection;
@property (strong, nonatomic) IBOutlet UIBarButtonItem *searchButton;
@property (strong, nonatomic) IBOutlet UIPickerView *userPicker;
@property (strong, nonatomic)          NSArray *userSelectArray;

@end

一如既往，提前致谢。

Answer 1

如果您将按钮设为 View 的属性，您可以直接访问它(而不是使用发送器)。

但为什么不直接从选择器中获取而不是间接从按钮标题中获取呢？

编辑:

所以根据你的代码，你想添加另一个按钮

@implementation RendezvousViewController{
     UIButton *selectButton;
}

初始化

-(void)viewDidLoad {
     selectButton = [[UIButton alloc] init];
     ...
}

然后在选择器中设置标题

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

    NSLog(@"Selected Row %ld", (long)row);
    switch(row)
    {
        case 0:
            self.selectButton.title = @"Breakfast";
            break;
      ...
    }
}

然后在选择其他按钮时捕获它:

- (IBAction)toolbarButtonPress:(id)sender {
    NSString *buttonTitle = [self.selectButton.title lowercaseString];
    [self queryGooglePlaces:buttonTitle];
    //Use the above title text to build the URL query and get the data from Google.
}



@implementation RendezvousViewController{
     UIButton *selectButton;
     NSString *selection;
}

不过，我建议使用另一个属性来存储所选的值，而不是依赖于您的 UI，例如按钮标题。它看起来像这样:

初始化

-(void)viewDidLoad {
     selectButton = [[UIButton alloc] init];
     selection = @"";
     ...
}

然后在选择器中设置标题

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

    NSLog(@"Selected Row %ld", (long)row);
    switch(row)
    {
        case 0:
            selection = @"Breakfast";


            break;
      ...
    }
    self.selectButton.title = selection;
}

然后在选择其他按钮时捕获它:

- (IBAction)toolbarButtonPress:(id)sender {
    [self queryGooglePlaces:selection];
    //Use the above title text to build the URL query and get the data from Google.
}