UI Advanced Uipickerview---ordering system

One: Data source method

/** Data source protocol, all methods must be implemented */

@protocol uipickerviewdatasource<nsobject>

@required

Returns the number of columns to display

-(Nsinteger) Numberofcomponentsinpickerview: (Uipickerview *) Pickerview;

Returns the number of data rows in the component column

-(Nsinteger) Pickerview: (Uipickerview *) Pickerview numberofrowsincomponent: (nsinteger) component;

@end

Two: Agent method:

* * Proxy protocol, all methods are optional */

@protocol uipickerviewdelegate<nsobject>

@optional

Returns the width of the specified column

-(CGFloat) Pickerview: (Uipickerview *) Pickerview widthforcomponent: (nsinteger) component;

Returns the row height of the specified column

-(CGFloat) Pickerview: (Uipickerview *) Pickerview rowheightforcomponent: (nsinteger) component;

/**

The following three returns the contents of the corresponding row for the specified column

Can be:

1> NSString

2> nsattributedstring

If the above two methods are implemented at the same time, it is preferable to select the Nsattributedstring proxy method execution

3> UIView

If the view is not visible, the system caches the unused views and callbacks for reuse

If a different object is returned, the callback view is released

The custom view is displayed in the middle of the row

*/

-(NSString *) Pickerview: (Uipickerview *) Pickerview Titleforrow: (nsinteger) Row forcomponent: (Nsinteger) component;

-(Nsattributedstring *) Pickerview: (Uipickerview *) Pickerview Attributedtitleforrow: (nsinteger) row forComponent: ( Nsinteger) component Ns_available_ios (6_0);

-(UIView *) Pickerview: (Uipickerview *) Pickerview Viewforrow: (nsinteger) Row forcomponent: (Nsinteger) component Reusingview: (UIView *) view;

Row row in the Component column is selected

-(void) Pickerview: (Uipickerview *) Pickerview Didselectrow: (nsinteger) Row incomponent: (Nsinteger) component;

@end

Three: Common methods of Pickerview

Reload data for all columns

-(void) reloadallcomponents;

Reload data for the specified column

-(void) Reloadcomponent: (Nsinteger) component;

Selecting a row row in the specified component column does not trigger the proxy method

-(void) SelectRow: (Nsinteger) Row incomponent: (Nsinteger) component animated: (BOOL) animated; Scrolls the specified line to the middle position

Returns the currently selected row, or 1 if no row is selected

-(Nsinteger) Selectedrowincomponent: (Nsinteger) component;

Four: Ordering system code implementation:

#import "ViewController.h"@interfaceViewcontroller () <uipickerviewdatasource, uipickerviewdelegate>-(ibaction) Selectanyfood; @property (weak, nonatomic) Iboutlet Uipickerview*Pickview, @property (weak, nonatomic) Iboutlet UILabel*Fruitlab, @property (weak, nonatomic) Iboutlet UILabel*Foodlab, @property (weak, nonatomic) Iboutlet UILabel*Drinklab, @property (nonatomic, strong) Nsarray*Foods;@end@implementationViewcontroller#pragmaMark-Lazy Load data-(Nsarray *) foods{if(!_foods) {NSString*path = [[NSBundle mainbundle] Pathforresource:@"foods.plist"Oftype:nil]; Nsarray*foodsarr =[Nsarray Arraywithcontentsoffile:path]; _foods=Foodsarr; }    return_foods;}- (void) viewdidload {[Super viewdidload]; //additional setup after loading the view, typically from a nib. //The view is loaded and the No. 0 row of data is displayed by default     for(inti =0; i<self.foods.count; i++) {[Self Pickerview:nil didselectrow:0INCOMPONENT:I]; }    }#pragmaMark-Data Source Method-(Nsinteger) Numberofcomponentsinpickerview: (Uipickerview *) pickerview{returnSelf.foods.count;}-(Nsinteger) Pickerview: (Uipickerview *) Pickerview numberofrowsincomponent: (nsinteger) component{//Note Why Self.foods[component] cannot point out count with dot syntax?     /** [Self.foods objectatindex:0]; = = self.foods[0];//The effect of the two sentences is equivalent, and self calls objectatindex:0 this method, returns a universal pointer of type ID,     Its true type is not detected until it is actually run, so it is not possible to use Self.foods[0].count directly. */    return[Self.foods[component] count];}#pragmaMark-Proxy Method-(NSString *) Pickerview: (Uipickerview *) Pickerview Titleforrow: (nsinteger) Row forcomponent: (nsinteger) component{returnSelf.foods[component][row];}- (void) Pickerview: (Uipickerview *) Pickerview Didselectrow: (nsinteger) Row incomponent: (nsinteger) component{if(Component = =0) {Self.fruitLab.text=Self.foods[component][row]; } Else if(Component = =1) {Self.foodLab.text=Self.foods[component][row]; } Else{Self.drinkLab.text=Self.foods[component][row]; }}/** * Random order*/-(ibaction) Selectanyfood { for(inti =0; i<self.foods.count; i++) {                //Remove the selected row        intRow = (int) [Self.pickview selectedrowincomponent:i]; intRandom;  Do{Random= Arc4random ()%[Self.foods[i] count]; }  while(Row = =random);        [Self.pickview selectrow:random incomponent:i Animated:yes];    [Self Pickerview:nil didselectrow:random incomponent:i]; }}@end

Effect:

V: Flag Display Code:

Data model

#import <Foundation/Foundation.h>@interface**icon; -(Instancetype) Initwithdic: (Nsdictionary *) dic; + (Instancetype) Flagwithdic: (Nsdictionary *) dic; + (Nsarray *) flagslist; @end

#import "LLFlag.h"@implementationLlflag-(Instancetype) Initwithdic: (Nsdictionary *) dic{if(self =[Super Init])    {[Self setvaluesforkeyswithdictionary:dic]; }    returnSelf ;}+ (Instancetype) Flagwithdic: (Nsdictionary *) dic{return[Self alloc] initwithdic:dic];}+ (Nsarray *) flagslist{NSString*path = [[NSBundle mainbundle] Pathforresource:@"Flags"OfType:@"plist"]; Nsarray*dicarr =[Nsarray Arraywithcontentsoffile:path]; Nsmutablearray*tmparr =[[Nsmutablearray alloc] initWithCapacity:dicArr.count];  for(Nsdictionary *dicinchDicarr) {Llflag*flag =[Llflag Flagwithdic:dic];    [Tmparr Addobject:flag]; }    returnTmparr;}@end

Xib Load View

#import <UIKit/UIKit.h>@class  llflag; @interface  *flag; + (instancetype) Flagview; @end

#import "LLFlagView.h"#import "LLFlag.h"@interfaceLlflagview () @property (weak, nonatomic) Iboutlet UILabel*Namelabel, @property (weak, nonatomic) Iboutlet Uiimageview*IconView;@end@implementationLlflagview+(instancetype) flagview{Llflagview*view = [[[NSBundle Mainbundle] loadnibnamed:@"Llflagview"Owner:nil Options:nil] lastobject]; returnview;}- (void) Setflag: (Llflag *) flag{_flag=Flag; Self.nameLabel.text=Flag.name; Self.iconView.image=[UIImage ImageNamed:flag.icon];}@end

Controller

#import "ViewController.h"#import "LLFlag.h"#import "LLFlagView.h"@interfaceViewcontroller () <uipickerviewdatasource, uipickerviewdelegate>@property (nonatomic, strong) Nsarray*flags; @property (weak, nonatomic) Iboutlet Uipickerview*Pickview;@end@implementationViewcontroller#pragmaMark-Lazy Loading-(Nsarray *) flags{if(!_flags) {_flags=[Llflag flagslist]; }    return_flags;}- (void) viewdidload {[Super viewdidload]; //additional setup after loading the view, typically from a nib.}#pragmaMark-Data Source Method-(Nsinteger) Numberofcomponentsinpickerview: (Uipickerview *) pickerview{return 1;}-(Nsinteger) Pickerview: (Uipickerview *) Pickerview numberofrowsincomponent: (nsinteger) component{returnSelf.flags.count;}-(UIView *) Pickerview: (Uipickerview *) Pickerview Viewforrow: (nsinteger) Row forcomponent: (Nsinteger) component Reusingview: (UIView *) view{Llflagview*flagview =[Llflagview Flagview]; Flagview.flag=Self.flags[row]; returnFlagview;}-(CGFloat) Pickerview: (Uipickerview *) Pickerview rowheightforcomponent: (nsinteger) component{return  -;}@end

Effect:

VI: Add:

Why [Self.foods[0] count] is used in the code implementation; Instead of directly using the point syntax self.foods[0].count to take a value.

[Self.foods objectatindex:0]; = = self.foods[0];//The effect of the two sentences is equivalent, and the self call objectatindex:0 this method, return is an ID type of the universal pointer, its real type to the actual run time can be detected, so can not directly use Self.foods [0].count.

UI Advanced Uipickerview---ordering system