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]; 
         
    } 
}