选择器控件UIPickerView:
功能：它能够创建一个类似于密码锁式的单列或多列的选择菜单，用户可以通过它设置的代理来选择需要菜单中的任意的数据。例如创建日历、字体表(类型、大小、颜色)、图库等.
它是UIView视图的子类，而且遵从UIPickerViewDelegate协议和UIPickerViewDataSource协议。因此，选择器需要设置代理去进行操作;
设置视图控制器self为数据源代理和数据操作代理,即
@property(strong,nonatomic)UIPickerView *pickerView;
self.pickerView.dataSource = self;
self.pickerView.delegate = self;
一、具体类信息：
@protocol UIPickerViewDataSource, UIPickerViewDelegate;
@interface UIPickerView : UIView <NSCoding>
@property(nonatomic,assign) id<UIPickerViewDataSource> dataSource; // default is nil,设置代理
@property(nonatomic,assign) id<UIPickerViewDelegate> delegate; // default is nil，设置代理
@property(nonatomic) BOOL showsSelectionIndicator; // default is NO
@property(nonatomic,readonly) NSInteger numberOfComponents; //列数
二、协议UIPickerViewDataSource
@protocol UIPickerViewDataSource<NSObject>
@required //必须要实现的方法
// 返回的列显示的数量。
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;
//返回行数在每个组件(每一列)
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;
@end
三、协议UIPickerViewDelegate
@protocol UIPickerViewDelegate<NSObject>
@optional //可以选择执行的方法
//每一列组件的列宽度
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component;
//每一列组件的行高度
- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component;
// 返回每一列组件的每一行的标题内容
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component;
// 返回每一列组件的每一行的标题内容的属性
- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component;
// 返回每一列组件的每一行的视图显示
- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view;
//执行选择某列某行的操作
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component;
@end
演示一：制作简单的万年历,一开始就显示当前日期
源码如下：
#import <UIKit/UIKit.h> @interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>
@property(nonatomic,strong)NSArray *years;
@property(nonatomic,strong)NSArray *months;
@property(nonatomic,strong)NSArray *days; @end
#import "ViewController.h" @interface ViewController ()
@property (weak, nonatomic) IBOutlet UIPickerView *pickerView; @end @implementation ViewController - (void)viewDidLoad
{
[super viewDidLoad];
//初始化数据
NSMutableArray *multYears = [NSMutableArray array];//年
for(int i=; i<; i++)
{
NSString *year = [NSString stringWithFormat:@"20%02d年",i+];
[multYears addObject:year];
}
self.years = multYears; NSMutableArray *multMonths = [NSMutableArray arrayWithCapacity:];//月
for(int i=; i<=; i++)
{
NSString *month = [NSString stringWithFormat:@"%d月",i];
[multMonths addObject:month];
}
self.months = multMonths; NSMutableArray *multDays = [NSMutableArray arrayWithCapacity:];//日
for(int i=; i<=; i++)
{
NSString *day = [NSString stringWithFormat:@"%d日",i];
[multDays addObject:day];
}
self.days = multDays; //设置pickerView的数据源和代理
self.pickerView.dataSource = self;
self.pickerView.delegate = self; //显示当前日期
NSDate *now = [NSDate date];
//分解日期
NSCalendar *calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSCalendarIdentifierGregorian]; NSCalendarUnit unitFlags = NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay;
NSDateComponents *components = [calendar components:unitFlags fromDate:now]; //设置pickerView显示当前日期
NSInteger year = [components year];
[self.pickerView selectRow:year-- inComponent: animated:year]; NSInteger month = [components month];
[self.pickerView selectRow:month- inComponent: animated:month]; NSInteger day = [components day];
[self.pickerView selectRow:day- inComponent: animated:day];
} #pragma mark - pickerView的代理方法
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return ;
}
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
NSInteger row = ;
switch (component)
{
case :
row = self.years.count;
break;
case :
row = self.months.count;
break;
case :
row = self.days.count;
break;
}
return row;
} -(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
NSString *title;
switch (component)
{
case :
title = self.years[row];
break;
case :
title = self.months[row];
break;
case :
title = self.days[row];
break;
}
return title;
}
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
NSString *strDate = [NSString stringWithFormat:@"%@-%@-%@",
self.years[[pickerView selectedRowInComponent:]],
self.months[[pickerView selectedRowInComponent:]],
self.days[[pickerView selectedRowInComponent:]]];
NSLog(@"%@",strDate);
}
@end
演示二：制作简单的字体表,包括字体类型、大小、颜色
源码如下：
#import <UIKit/UIKit.h> @interface ViewController : UIViewController<UIPickerViewDataSource,UIPickerViewDelegate>
@property(nonatomic,strong) NSArray *fontNames;
@property(nonatomic,strong) NSArray *fontSizes;
@property(nonatomic,strong) NSArray *fontColors;
@end
#import "ViewController.h" @interface ViewController ()
@property (weak, nonatomic) IBOutlet UILabel *label;
@property (weak, nonatomic) IBOutlet UIPickerView *pickerView; @end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad];
//初始化数据
self.fontNames = [UIFont familyNames];//字体名字 NSMutableArray *mutsize = [NSMutableArray arrayWithCapacity:];//字体大小
for(int i=; i<=; i++)
{
[mutsize addObject:[NSString stringWithFormat:@"%d",+i]];
}
self.fontSizes = mutsize; self.fontColors = @[
@{@"name":@"红色",@"color":[UIColor redColor]},
@{@"name":@"黑色",@"color":[UIColor blackColor]},
@{@"name":@"蓝色",@"color":[UIColor blueColor]},
@{@"name":@"黄色",@"color":[UIColor yellowColor]},
@{@"name":@"绿色",@"color":[UIColor greenColor]}
];
//设置pickerView的代理和数据源
self.pickerView.dataSource = self;
self.pickerView.delegate = self; //设置label的font
self.label.font = [UIFont fontWithName:self.fontNames[] size:[self.fontSizes[] integerValue]]; self.label.textColor = [self.fontColors[] objectForKey:@"color"];
} #pragma mark - pickerView的代理方法
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return ;
}
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
NSInteger row = ;
switch (component)
{
case :
row = self.fontNames.count;
break;
case :
row = self.fontSizes.count;
break;
case :
row = self.fontColors.count;
break;
}
return row;
}
-(NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
NSString *title;
switch (component)
{
case :
title = self.fontNames[row];
break;
case :
title = self.fontSizes[row];
break;
case :
title = [self.fontColors[row] objectForKey:@"name"];
break;
}
return title;
}
//设置每一列的宽度
-(CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component
{
CGFloat width = 0.0f;
switch (component)
{
case :
width = pickerView.frame.size.width/;
break;
case :
width = pickerView.frame.size.width/;
break;
case :
width = pickerView.frame.size.width/;
break;
}
return width;
} -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
//设置label的font
self.label.font = [UIFont fontWithName:self.fontNames[[pickerView selectedRowInComponent:]] size:[self.fontSizes[[pickerView selectedRowInComponent:]] integerValue]]; self.label.textColor = [self.fontColors[[pickerView selectedRowInComponent:]] objectForKey:@"color"];
}
@end
演示三：制作简单的图库浏览器
源码如下：
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController<UIPickerViewDelegate,UIPickerViewDataSource>
@end
#import "ViewController.h" @interface ViewController ()
@property (weak, nonatomic) IBOutlet UIPickerView *pickerView;
@property (strong,nonatomic)NSArray *imageNames;
@end @implementation ViewController - (void)viewDidLoad {
[super viewDidLoad];
//初始化数据
NSMutableArray *mutImageNames = [NSMutableArray arrayWithCapacity:];
for(int i=; i<; i++)
{
[mutImageNames addObject:[NSString stringWithFormat:@"%d.png",i]];
}
self.imageNames = mutImageNames; //设置pickerView的数据源和代理
self.pickerView.dataSource = self;
self.pickerView.delegate = self; }
#pragma mark - pickerview代理方法
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return ;
}
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return self.imageNames.count;
}
//设置行高
-(CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component
{
UIImage *image = [UIImage imageNamed:self.imageNames[]];
return image.size.height;
}
//设置每行显示的视图
-(UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
UIImage *image = [UIImage imageNamed:self.imageNames[row]];
//UIImageView *imageView = [[UIImageView alloc]initWithImage:image];
//imageView.frame = CGRectMake(0, 0, image.size.width, image.size.height);
//return imageView; UIButton *button = [[UIButton alloc]initWithFrame:CGRectMake(, ,image.size.width, image.size.height)];
[button setBackgroundImage:image forState:UIControlStateNormal];
[button addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
return button;
}
-(void)buttonClicked:(UIButton *)sender
{
NSLog(@"button clicked");
}
@end