【代碼筆記】點擊加號增加書架，點擊減號減少書架，書架減號

【代碼筆記】點擊加號增加書架，點擊減號減少書架，書架減號

一，。

二，工程圖。

三，代碼。

ReaderViewController.h

#import <UIKit/UIKit.h>@interface ReaderViewController : UIViewController<UIScrollViewDelegate>{    UIScrollView *scrollView;}@property(nonatomic,strong) UIScrollView *scrollView;;-(void)add;-(void)dele;-(void)reloadView;@end

 

ReaderViewController.m

#import "ReaderViewController.h"#define ImageHeight 120static int num = 0;@interface ReaderViewController ()@end@implementation ReaderViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];    if (self) {        // Custom initialization    }    return self;}- (void)viewDidLoad{    [super viewDidLoad];    // Do any additional setup after loading the view.        //字型的顏色    self.navigationController.navigationBar.tintColor = [UIColor colorWithRed:248.0/255.0 green:172.0/255.0 blue:37.0/255.0 alpha:1.0];    //導覽列背景圖    [self addBackgroundView:@"1.png"];        //左側刪除按鈕    UIBarButtonItem *rightBarButton = [[UIBarButtonItem alloc]                                       initWithTitle:@"delete"                                       style:UIBarButtonItemStyleBordered                                       target:self                                       action:@selector(dele)];    //右側增加按鈕    UIBarButtonItem *leftBarButton = [[UIBarButtonItem alloc]                                      initWithBarButtonSystemItem:UIBarButtonSystemItemAdd                                      target:self                                      action:@selector(add)];        self.navigationItem.rightBarButtonItem = rightBarButton;    self.navigationItem.leftBarButtonItem = leftBarButton;        //scrollerView    scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, 320, 416)];    scrollView.contentSize=CGSizeMake(320,480);        //設定背景顏色    UIImage *backimg=[UIImage imageNamed:@"3.png"];    UIImageView *backview=[[UIImageView alloc] initWithImage:backimg];    backview.frame=CGRectMake(0, 0, 320, 480);    [self.view addSubview:backview];        [self.view addSubview:scrollView];    //重新重新整理介面    [self reloadView];}//導覽列上標題-(void)addBackgroundView:(NSString*)image{        UIImageView *imgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:image]];    imgView.frame = CGRectMake(0, 0, 320, 44);    [self.navigationController.navigationBar addSubview: imgView];        UILabel *title = [[UILabel alloc] initWithFrame:CGRectMake((320-150)/2, 0, 150, 44)];    [title setText:@"書架"];    [title setTextColor:[UIColor whiteColor]];    [title setTextAlignment:NSTextAlignmentCenter];    [title setShadowColor:[UIColor grayColor]];    [title setBackgroundColor:[UIColor clearColor]];    [title setFont:[UIFont boldSystemFontOfSize:20.0]];    [self.navigationController.navigationBar addSubview:title];}//添加一個書架-(void)add{        num++;        UIImage *backimg=[UIImage imageNamed:@"2.png"];    UIImageView *backview=[[UIImageView alloc] initWithImage:backimg];    backview.frame=CGRectMake(0, (num-1)*ImageHeight, 320, ImageHeight);    backview.tag = num+100;        [scrollView addSubview:backview];        if (num>3) {        scrollView.contentSize=CGSizeMake(320,num*ImageHeight);    }}//刪除一個書架-(void)dele{        if (num<=0) {        return;    }        for (UIView *view in scrollView.subviews) {        if(view.tag == (num+100))            [view removeFromSuperview];    }        num--;        if (num>3) {        scrollView.contentSize=CGSizeMake(320,num*ImageHeight);    }    }//主介面初始化-(void)reloadView{        NSLog(@"reloadView");    //遍曆當前介面的所有子介面，把子介面刪除乾淨    for(UIView *view in scrollView.subviews){        [view removeFromSuperview];    }        scrollView.showsVerticalScrollIndicator=NO;    scrollView.showsHorizontalScrollIndicator=NO;    scrollView.delegate=self;    [scrollView setScrollEnabled:YES];    }- (void)didReceiveMemoryWarning{    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}