如何创建自定义UIDatePicker？

就像rmaddy提到的那样，您将需要使用UIPickerView。UIDatePicker仅用于选择日期/时间。这是苹果文档的链接：

https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UIPickerView_Class/index.html

以下是一些帮助您入门的提示：

1）UIPickerView在的实例上创建type属性UIViewController。我称其pickerView为演示目的。

2）pickerView分配init或将其链接到pickerView情节提要/ xib文件上的。

3）确保将的设置为delegate的pickerView实例UIViewController。

4）确保您的实例UIViewController实现了以下协议：UIPickerViewDataSource并UIPickerViewDelegate通过在您的UIViewController子类的接口声明旁边添加以下代码行：

<UIPickerViewDataSource, UIPickerViewDelegate>

5）实际实现的必要方法（以及任何可选）UIPickerViewDataSource和UIPickerViewDelegate。通过这种方式，您可以知道pickerView它有多少行和列，以及用什么文本填充所说的行和列。

一些示例代码如下所示：

// MyViewController.h

@interface MyViewController : UIViewController <UIPickerViewDataSource, UIPickerViewDelegate>

@property (weak, nonatomic) IBOutlet UIPickerView *pickerView;

@end

// MyViewController.m

@implementation MyViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.pickerView.delegate = self;
}

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
    // components are like columns. one column for feet and one for inches
    return 2;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    if(component == 0){
        return [[self getUserDetailsHeightFeetOptions]count];
    } else {
        return [[self getUserDetailsHeightInchesOptions]count];
    }
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component{
    if(component == 0){
        return [NSString stringWithFormat:@"%@", [[self getUserDetailsHeightFeetOptions]objectAtIndex:row]];
    } else {
        return [NSString stringWithFormat:@"%@", [[self getUserDetailsHeightInchesOptions]objectAtIndex:row]];
    }
}

- (NSArray*)getUserDetailsHeightFeetOptions{
    NSMutableArray *feetOptions = [[NSMutableArray alloc]init];
    for (int i = 3; i < 8; i++) {
        [feetOptions addObject:[NSNumber numberWithInt:i]];
    }
    return feetOptions;
}

- (NSArray*)getUserDetailsHeightInchesOptions{
    NSMutableArray *inchesOptions = [[NSMutableArray alloc]init];
    for (int i = 0; i < 12; i++) {
        [inchesOptions addObject:[NSNumber numberWithInt:i]];
    }
    return inchesOptions;
}