代码改变世界

自定义日期挑选控件

2011-01-26 09:52  乱世文章  阅读(693)  评论(0编辑  收藏  举报

cocoa提供了UIDatePicker控件,但是对于程序员而言并不友好。其糟糕之处,莫过于无法指定其frame,它的大小固定为320*216(占据了近整个iphone屏幕的一半),导致在UI设计时很难安排下这个“巨大”的东西。

我们自定义的日期挑选控件是这样的。

它默认情况下显示为一个textfield,以文本的方式显示日期,当你试图编辑它时,会弹出一个足够巨大的UIDatePicker控件:

 

转动日期轮盘时,其实textfield中的值会作相应改变。选择好日期后,点击左上角的关闭按钮关闭这个UIDatePicker。

这个控件的使用非常简单。

通常只需要通过下面的代码构造它并addSubview就可以了:

DatePicker* dp=[[DatePicker alloc]initWithFrame:CGRectMake (10,25,220,35)];

[self.view addSubview:dp];

如果想改变DatePicker的样式,比如显示时间而不是日期,可以修改其datePickerMode和dateFormatter属性:

dp.datePickerMode=UIDatePickerModeTime;

NSDateFormatter* df=[[NSDateFormatter alloc]init];

[df setDateFormat:@"HH:mm:ss"];

dp.dateFormatter=df;

如果要获取控件的日期时间值和字符串值,则可以使用控件的date属性和textField.text属性。

 

全部的源代码在这里:

============DatePicker.h===========

@interface DatePicker : UIView

<UITextFieldDelegate>{

UITextField* textField;//文本框

UIDatePicker* datePicker;//日期选择控件

NSDateFormatter *dateFormatter;//日期格式

UIDatePickerMode datePickerMode;//日期控件显示风格

NSDate* date;

UIView* subview;

}

@property(nonatomic) UIDatePickerMode datePickerMode;

//@property(nonatomic,retain)UITextField* textField;

@property(nonatomic,retain)NSDateFormatter* dateFormatter;

@property(nonatomic,retain)NSDate* date;

//@property(nonatomic,retain)UIDatePicker* datePicker;

-(UIDatePickerMode)datePickerMode;

-(void)setDatePickerMode:(UIDatePickerMode)mode;

-(NSDateFormatter*)dateFormatter;

-(void)setDateFormatter:(NSDateFormatter *)df;

-(NSDate*)date;

-(void)setDate:(NSDate*)d;

-(UITextField*)textField;

-(UIDatePicker*)datePicker;

@end

==============DatePicker.m==============

#import "DatePicker.h"

 

@implementation DatePicker

-(UIDatePicker*)datePicker

{

return datePicker;

}

-(UITextField*)textField

{

return textField;

}

-(NSDate*)date

{

return date;

}

-(void)setDate:(NSDate *)d

{

date=d;

datePicker.date=date;

}

-(NSDateFormatter*)dateFormatter

{

return dateFormatter;

}

-(void)setDateFormatter:(NSDateFormatter *)df{

dateFormatter=df;

textField.text=[dateFormatter stringFromDate:date];

}

-(UIDatePickerMode)datePickerMode

{

return datePickerMode;

}

-(void)setDatePickerMode:(UIDatePickerMode)mode{

datePickerMode=mode;

datePicker.datePickerMode=datePickerMode;

}

- (id)initWithFrame:(CGRect)frame {

    if ((self = [super initWithFrame:frame])) {

//默认日期格式为yyyy-MM-dd

dateFormatter= [[NSDateFormatter alloc] init];

[dateFormatter setLocale:[[NSLocale alloc]initWithLocaleIdentifier:@"zh_CN"]];//location设置为中国

[dateFormatter setDateFormat:@"yyyy-MM-dd"];

//picker的默认时间为当前时间

date=[NSDate date];

//picker的默认style为只显示日期

datePickerMode=UIDatePickerModeDate;

//构造一个子视图,用于显示日期选择器

subview=[[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 480)];

subview.backgroundColor=[UIColor clearColor];

subview.tag=0;

//为子视图构造工具栏按钮

UIBarButtonItem* item = [[[UIBarButtonItem alloc]  

  initWithBarButtonSystemItem:UIBarButtonSystemItemStop

  target:self action:@selector(btnCloseClick)] autorelease];

NSArray* buttons=[NSArray arrayWithObjects:item,nil];

//为子视图构造工具栏

UIToolbar *subToolbar=[[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 44)];

subToolbar.barStyle = UIBarStyleBlackTranslucent; 

[subToolbar sizeToFit];

  [subToolbar setItems:buttons animated:YES]; //把按钮加入工具栏

[subview addSubview:subToolbar];//把工具栏加入子视图

[subToolbar release];

//为子视图构造datePicker

datePicker=[[UIDatePicker alloc]init];

[datePicker setDate:date];

datePicker.frame=CGRectMake(0, 44, 320, 216);

datePicker.datePickerMode=datePickerMode;

//指定datepickervalueChanged事件

[datePicker addTarget:self action:@selector(dateChanged:) forControlEvents:UIControlEventValueChanged];

[subview addSubview:datePicker]; //datePicker加入子视图

//上面是子视图,下面是父视图

//文本框

        textField=[[UITextField alloc]initWithFrame:frame];

textField.delegate=self;

// textField.enabled=NO;

textField.borderStyle=UITextBorderStyleRoundedRect;

textField.text=[dateFormatter stringFromDate:date];

[self addSubview:textField];

    }

    return self;

}

//datepicker的值改变时触发

-(void)dateChanged:(id)sender{

date = [sender date];//获取datepicker的日期

//改变textField的值

textField.text=[NSString stringWithString:

 [dateFormatter stringFromDate:date]];

}

//关闭按钮点击时触发

-(void)btnCloseClick{

if(subview!=nil){

subview.tag=0;

[subview removeFromSuperview];

}

}

 

- (void)dealloc {

[textField release];

[date release];

[dateFormatter release];

[datePicker release];

[subview release];

    [super dealloc];

}

#pragma mark textField delegate method

//textField被点击时触发

-(BOOL)textFieldShouldBeginEditing:(UITextField *)textField{

if (subview.tag==0) {//tag标志等于0,说明datepicker未显示

//tag标志为1,并显示子视图

subview.tag=1;

[self.superview addSubview:subview];

}

return NO;

}

 

@end