筆記

singlecomponent Picker：

 //.h文件

@property (strong, nonatomic) IBOutlet UIPickerView *singlePicker;

@property (strong, nonatomic) NSArray *pickerData;

- (IBAction)buttonPressed; 

//.m文件

@synthesize singlePicker;
@synthesize pickerData;
- (IBAction)buttonPressed {
NSInteger row = [singlePicker selectedRowInComponent:0];
NSString *selected = [pickerData objectAtIndex:row];
NSString *title = [[NSString alloc] initWithFormat:
@"You selected %@!", selected];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title
message:@"Thank you for choosing."
delegate:nil
cancelButtonTitle:@"You're Welcome"
otherButtonTitles:nil];
[alert show];
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
NSArray *array = [[NSArray alloc] initWithObjects:@"Luke", @"Leia",
@"Han", @"Chewbacca", @"Artoo", @"Threepio", @"Lando", nil];
self.pickerData = array;
}

Both NSArray and NSDictionary offer a method called initWithContentsOfFile: to allow you to initialize instances from a property list file

//加到尾部

#pragma mark -
#pragma mark Picker Data Source Methods
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return 1;
}
- (NSInteger)pickerView:(UIPickerView *)pickerView
numberOfRowsInComponent:(NSInteger)component {
return [pickerData count];
}
#pragma mark Picker Delegate Methods
- (NSString *)pickerView:(UIPickerView *)pickerView
titleForRow:(NSInteger)row
CHAPTER 7: Tab Bars and Pickers 191
forComponent:(NSInteger)component {
return [pickerData objectAtIndex:row];
}