ios学习2-图片切换

标签：

用到的知识点有：

1.storyboard和viewcontroller.m之间的连线

2.资源文件.plist  使用

3.NSDictionary类的使用

4.NSArray使用

5.UIImageView使用

自己跟着视屏学习做的第二个例子：一共五张图片，点击按钮左右切换显示图片，功能很基础。

写ios程序的步骤：写布局，连线，写action等

就几个布局，拖一拖就好。连线也是。代码如下

#import "ViewController.h"

@interface ViewController ()

@property (weak, nonatomic) IBOutlet UILabel *noLable;
@property (weak, nonatomic) IBOutlet UILabel *descLable;
@property (weak, nonatomic) IBOutlet UIImageView *mainView;
@property (weak, nonatomic) IBOutlet UIButton *leftBtn;
@property (weak, nonatomic) IBOutlet UIButton *rightBtn;

@property (assign,nonatomic) int currentPosition;
@property (weak, nonatomic) NSArray *imagesData;

@end

@implementation ViewController

-(NSArray *)imagesData{
    if (_imagesData == nil) {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"imageData" ofType:@"plist"];
        _imagesData = [NSArray arrayWithContentsOfFile:path];
    }
    
    return _imagesData;
}

- (void)viewDidLoad {
    [super viewDidLoad];
    self.currentPosition = 0;
    [self changeImage];
}

- (void)changeImage {
    self.noLable.text = [NSString stringWithFormat:@"%d/%d",self.currentPosition + 1,self.imagesData.count];
    self.descLable.text = self.imagesData[self.currentPosition][@"desc"];
    self.mainView.image = [UIImage imageNamed:self.imagesData[self.currentPosition][@"icon"]];
    self.leftBtn.enabled = (self.currentPosition != 0);
    self.rightBtn.enabled = (self.currentPosition != (self.imagesData.count - 1));
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)right:(UIButton *)sender {
    self.currentPosition++;
    [self changeImage];
}

- (IBAction)left:(UIButton *)sender {
    self.currentPosition--;
    [self changeImage];
}


@end

主要是学习了这些语句的使用：

1.重写了imagesData方法，这样用点运算，获取变量时，就会对变量进行赋值。

-(NSArray *)imagesData{
    if (_imagesData == nil) {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"imageData" ofType:@"plist"];
        _imagesData = [NSArray arrayWithContentsOfFile:path];
    }
    
    return _imagesData;
}

2.nsbutton设置状态：起到改变颜色的效果

self.rightBtn.enabled = (self.currentPosition != (self.imagesData.count - 1));

3.NSDictionary对象调用的时候用   obj［@“属性名字”］

self.descLable.text = self.imagesData[self.currentPosition][@"desc"];

ios学习2-图片切换

标签：

原文地址：http://blog.csdn.net/u013173289/article/details/45795365