实例讲解iOS应用开发中UIPickerView滚动选择栏的用法

@property(nonatomic,assign) id dataSource;

@property(nonatomic,assign) id   delegate;

@property(nonatomic)   BOOL   showsSelectionIndicator;

@property(nonatomic,readonly) NSInteger numberOfComponents;

- (void)reloadAllComponents;

- (void)reloadComponent:(NSInteger)component;

- (void)selectRow:(NSInteger)row inComponent:(NSInteger)component animated:(BOOL)animated;

- (NSInteger)selectedRowInComponent:(NSInteger)component;

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component;

- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component;

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component;

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view;

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

- (void)viewDidLoad {  
    [super viewDidLoad];  
    // Do any additional setup after loading the view, typically from a nib.  
      
    // 选择框  
    UIPickerView *pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 100, 320, 216)];  
    // 显示选中框  
    pickerView.showsSelectionIndicator=YES;  
    pickerView.dataSource = self;  
    pickerView.delegate = self;  
    [self.view addSubview:pickerView];  
      
    _proTimeList = [[NSArray alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",nil];  
    _proTitleList = [[NSArray alloc]initWithObjects:@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"10",nil];  
                   
                       
}  

#pragma Mark -- UIPickerViewDataSource  
// pickerView 列数  
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {  
    return 2;  
}  
  
// pickerView 每列个数  
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {  
    if (component == 0) {  
        return [_proTitleList count];  
    }  
      
    return [_proTimeList count];  
}  

#pragma Mark -- UIPickerViewDelegate  
// 每列宽度  
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {  
      
    if (component == 1) {  
        return 40;  
    }  
    return 180;  
}  
// 返回选中的行  
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component  
{  
    if (component == 0) {  
        NSString  *_proNameStr = [_proTitleList objectAtIndex:row];  
        NSLog(@"nameStr=%@",_proNameStr);  
    } else {  
        NSString  *_proTimeStr = [_proTimeList objectAtIndex:row];  
        NSLog(@"_proTimeStr=%@",_proTimeStr);  
    }  
      
}  
  
//返回当前行的内容,此处是将数组中数值添加到滚动的那个显示栏上  
-(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component  
{  
    if (component == 0) {  
        return [_proTitleList objectAtIndex:row];  
    } else {  
        return [_proTimeList objectAtIndex:row];  
          
    }  
}