iOS开发中实现一个简单的图片浏览器的实例讲解

2020-07-26 03:29:46

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一、程序实现要求

1.要求

201611392120159.png (663×410)

2. 界面分析

（1）需要读取或修改属性的控件需要设置属性

序号标签
图片
图片描述
左边按钮
右边按钮

（2）需要监听响应事件的对象，需要添加监听方法

左边按钮
右边按钮

二、实现基本功能的程序

复制代码代码如下:

//
// YYViewController.m
// 03-图片浏览器初步
//
// Created by apple on 14-5-21.
// Copyright (c) 2014年 itcase. All rights reserved.
//

#import "YYViewController.h"

#define POTOIMGW    200
#define POTOIMGH    300
#define POTOIMGX    60
#define POTOIMGY    50

@interface YYViewController ()

//变量声明！
@property(nonatomic,strong)UILabel *firstlab;
@property(nonatomic,strong)UILabel *lastlab;
@property(nonatomic,strong)UIImageView *icon;
@property(nonatomic,strong)UIButton *leftbtn;
@property(nonatomic,strong)UIButton *rightbtn;

-(void)change;
@property(nonatomic ,assign)int i;
@end

@implementation YYViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.i=0;
    //创建一个用来显示序号的lable控件
    UILabel *headlab=[[UILabel alloc]initWithFrame:CGRectMake(20, 10, 300, 30)];

// [headlab setText:@"1/5"];
    [headlab setTextAlignment:NSTextAlignmentCenter];
    [headlab setTextColor:[UIColor blackColor]];

    [self.view addSubview:headlab];
    self.firstlab=headlab;



    //创建一个装载图片的控件
    UIImageView *potoimg=[[UIImageView alloc]initWithFrame:CGRectMake(POTOIMGX, POTOIMGY, POTOIMGW, POTOIMGH)];

    UIImage *image=[UIImage imageNamed:@"biaoqingdi"];
    potoimg.image=image;

    [self.view addSubview:potoimg];
    self.icon=potoimg;



    //创建最下边的描述图片的lable控件
    UILabel *desclab=[[UILabel alloc]initWithFrame:CGRectMake(20, 400, 300, 30)];
   // [desclab setText:@"表情弱爆了！"];
    [desclab setTextAlignment:NSTextAlignmentCenter];
    [self.view addSubview:desclab];
    self.lastlab=desclab;


    //创建两个方向键按钮
    //设置为自定义类型
    //1.使用类创建对象
    UIButton *leftbtn=[UIButton buttonWithType:UIButtonTypeCustom];

    //2.设置对象的属性（不要忘记设置坐标）
    leftbtn.frame=CGRectMake(0, self.view.center.y, 40, 40);
    [leftbtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal];
    [leftbtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted];

    //3.提交对象到视图
    [self.view addSubview:leftbtn];

    self.leftbtn=leftbtn;
    [leftbtn addTarget:self action:@selector(leftclick:) forControlEvents:UIControlEventTouchUpInside];


    UIButton *rightbtn=[UIButton buttonWithType:UIButtonTypeCustom];

    rightbtn.frame=CGRectMake(POTOIMGX+POTOIMGW+10, self.view.center.y, 40, 40);
    [rightbtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal];
    [rightbtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted];

    [self.view addSubview:rightbtn];

    self.rightbtn=rightbtn;
    [rightbtn addTarget:self action:@selector(rightclick:) forControlEvents:UIControlEventTouchUpInside];

    //这是一个初始化方法，调用change可以完成初始化的工作
    [self change];
}

-(void)change
{
    [self.firstlab setText:[NSString stringWithFormat:@"%d/5",self.i+1]];
    switch (self.i) {
        case 0:
            self.lastlab.text=@"什么表情都弱爆了！";
            self.icon.image=[UIImage imageNamed:@"biaoqingdi"];
            break;
        case 1:
            self.lastlab.text=@"病例";
            self.icon.image=[UIImage imageNamed:@"bingli"];
            break;
        case 2:
           self.lastlab.text=@"王八";
            self.icon.image=[UIImage imageNamed:@"wangba"];
            break;
        case 3:
           self.lastlab.text=@"吃牛扒";
            self.icon.image=[UIImage imageNamed:@"chiniupa"];
            break;
        case 4:
             self.lastlab.text=@"蛋疼！";
            self.icon.image=[UIImage imageNamed:@"danteng"];
            break;
    }
    //控制按钮的点击，如果为5则右键失效，如果为1，则左键失效
    self.leftbtn.enabled=(self.i!=0);
    self.rightbtn.enabled=(self.i!=4);

}

//向右按键
-(void)rightclick:(UIButton *)btn
{
    self.i++;
    [self change];
    //NSLog(@"点我了");
}
-(void)leftclick:(UIButton *)btn
{
    self.i--;
    [self change];
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

三、程序优化

复制代码代码如下:

//
// YYViewController.m
// 03-图片浏览器初步
//
// Created by apple on 14-5-21.
// Copyright (c) 2014年 itcase. All rights reserved.
//

#import "YYViewController.h"

#define POTOIMGW    200
#define POTOIMGH    300
#define POTOIMGX    60
#define POTOIMGY    50

@interface YYViewController ()

@property(nonatomic,strong)NSArray *array;

-(void)change;
@property(nonatomic ,assign)int i;
@end

复制代码代码如下:

@implementation YYViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.i=0;
    //创建一个用来显示序号的lable控件
    UILabel *headlab=[[UILabel alloc]initWithFrame:CGRectMake(20, 10, 300, 30)];

// [headlab setText:@"1/5"];
    [headlab setTextAlignment:NSTextAlignmentCenter];
    [headlab setTextColor:[UIColor blackColor]];

    [self.view addSubview:headlab];
    self.firstlab=headlab;



    //创建一个装载图片的控件
    UIImageView *potoimg=[[UIImageView alloc]initWithFrame:CGRectMake(POTOIMGX, POTOIMGY, POTOIMGW, POTOIMGH)];

    UIImage *image=[UIImage imageNamed:@"biaoqingdi"];
    potoimg.image=image;

    [self.view addSubview:potoimg];
    self.icon=potoimg;



    //创建最下边的描述图片的lable控件
    UILabel *desclab=[[UILabel alloc]initWithFrame:CGRectMake(20, 400, 300, 30)];
   // [desclab setText:@"表情弱爆了！"];
    [desclab setTextAlignment:NSTextAlignmentCenter];
    [self.view addSubview:desclab];
    self.lastlab=desclab;



    //创建两个方向键按钮
    //设置为自定义类型
    //1.使用类创建对象
    UIButton *leftbtn=[UIButton buttonWithType:UIButtonTypeCustom];

    //2.设置对象的属性（不要忘记设置坐标）
    leftbtn.frame=CGRectMake(0, self.view.center.y, 40, 40);
    [leftbtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal];
    [leftbtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted];

    //3.提交对象到视图
    [self.view addSubview:leftbtn];

    self.leftbtn=leftbtn;
    [leftbtn addTarget:self action:@selector(leftclick:) forControlEvents:UIControlEventTouchUpInside];


    UIButton *rightbtn=[UIButton buttonWithType:UIButtonTypeCustom];

    rightbtn.frame=CGRectMake(POTOIMGX+POTOIMGW+10, self.view.center.y, 40, 40);
    [rightbtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal];
    [rightbtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted];

    [self.view addSubview:rightbtn];

    self.rightbtn=rightbtn;
    [rightbtn addTarget:self action:@selector(rightclick:) forControlEvents:UIControlEventTouchUpInside];
    //放在这里的话，只会创建一次，但是这个部分和[self change];部分有很严格的顺序要求，并不人性化，可以考虑使用懒加载特性
//    NSDictionary *dict1=@{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了！"};
//    NSDictionary *dict2=@{@"name": @"bingli",@"desc":@"病例"};
//    NSDictionary *dict3=@{@"name": @"wangba",@"desc":@"乌龟"};
//    NSDictionary *dict4=@{@"name": @"chiniupa",@"desc":@"吃牛扒"};
//    NSDictionary *dict5=@{@"name": @"danteng",@"desc":@"蛋疼"};
//
//    self.array=@[dict1,dict2,dict3,dict4,dict5];
    //这是一个初始化方法，调用change可以完成初始化的工作
    [self change];
}

-(void)change
{
    //每次调用都需要创建？有没有什么解决办法？
//    NSDictionary *dict1=@{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了！"};
//    NSDictionary *dict2=@{@"name": @"bingli",@"desc":@"病例"};
//    NSDictionary *dict3=@{@"name": @"wangba",@"desc":@"乌龟"};
//    NSDictionary *dict4=@{@"name": @"chiniupa",@"desc":@"吃牛扒"};
//    NSDictionary *dict5=@{@"name": @"danteng",@"desc":@"蛋疼"};
//
//    NSArray *array=@[dict1,dict2,dict3,dict4,dict5];


    //设置照片
    //先根据self.i取出数组中的元素，再取出元素（字典）中键值对应的值
//    self.icon.image=[UIImage imageNamed:array[self.i][@"name"]];
//    self.lastlab.text=array[self.i][@"desc"];
   // NSLog(@"%@",array[self.i][@"desc"]);

    self.icon.image=[UIImage imageNamed:self.array[self.i][@"name"]];
    self.lastlab.text=self.array[self.i][@"desc"];

    [self.firstlab setText:[NSString stringWithFormat:@"%d/5",self.i+1]];

//    switch (self.i) {
//        case 0:
//            self.lastlab.text=@"什么表情都弱爆了！";
//            self.icon.image=[UIImage imageNamed:@"biaoqingdi"];
//            break;
//        case 1:
//            self.lastlab.text=@"病例";
//            self.icon.image=[UIImage imageNamed:@"bingli"];
//            break;
//        case 2:
//           self.lastlab.text=@"王八";
//            self.icon.image=[UIImage imageNamed:@"wangba"];
//            break;
//        case 3:
//           self.lastlab.text=@"吃牛扒";
//            self.icon.image=[UIImage imageNamed:@"chiniupa"];
//            break;
//        case 4:
//             self.lastlab.text=@"蛋疼！";
//            self.icon.image=[UIImage imageNamed:@"danteng"];
//            break;
//    }
    //控制按钮的点击，如果为5则右键失效，如果为1，则左键失效
    self.leftbtn.enabled=(self.i!=0);
    self.rightbtn.enabled=(self.i!=4);

}

//array的get方法
-(NSArray *)array
{
    NSLog(@"需要获取数组");
    //只实例化一次
    if (_array==nil) {
        NSLog(@"实例化数组");
        NSDictionary *dict1=@{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了！"};
        NSDictionary *dict2=@{@"name": @"bingli",@"desc":@"病例"};
        NSDictionary *dict3=@{@"name": @"wangba",@"desc":@"乌龟"};
        NSDictionary *dict4=@{@"name": @"chiniupa",@"desc":@"吃牛扒"};
        NSDictionary *dict5=@{@"name": @"danteng",@"desc":@"蛋疼"};
        _array=@[dict1,dict2,dict3,dict4,dict5];
    }
//    NSDictionary *dict1=@{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了！"};
//    NSDictionary *dict2=@{@"name": @"bingli",@"desc":@"病例"};
//    NSDictionary *dict3=@{@"name": @"wangba",@"desc":@"乌龟"};
//    NSDictionary *dict4=@{@"name": @"chiniupa",@"desc":@"吃牛扒"};
//    NSDictionary *dict5=@{@"name": @"danteng",@"desc":@"蛋疼"};

   // _array=@[dict1,dict2,dict3,dict4,dict5];
    return _array;
}

//向右按键
-(void)rightclick:(UIButton *)btn
{
self.i++;
[self change];
}

//向左按键
-(void)leftclick:(UIButton *)btn
{
self.i--;
[self change];
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}

@end

说明：

1> 定义控件属性，注意：属性必须是strong的，示例代码如下：

复制代码代码如下:

@property (nonatomic, strong) UIImageView *icon;

2> 在属性的getter方法中实现懒加载，示例代码如下：

复制代码代码如下:

- (UIImageView *)icon

{

if (!_icon) {

// 计算位置参数

CGFloat imageW = 200;

CGFloat imageX = (320 - imageW) / 2;

CGFloat imageH = 200;

CGFloat imageY = 80;

// 实例化图像视图

_icon = [[UIImageView alloc] initWithFrame:CGRectMake(imageX, imageY, imageW, imageH)];

// 将图像视图添加到主视图

[self.view addSubview:_icon];

}

return _icon;

}

四、使用plist文件

（1）使用Plist文件的目的：将数据与代码分离

（2）加载方法：

复制代码代码如下:

NSString *path = [[NSBundle mainBundle] pathForResource:@"ImageData" ofType:@"plist"];

_imageList = [NSArray arrayWithContentsOfFile:path];

提示：通常在方法中出现File字眼，通常需要传递文件的全路径作为参数

（3）代码示例

复制代码代码如下:

//
// YYViewController.m
// 03-图片浏览器初步
//
// Created by apple on 14-5-21.
// Copyright (c) 2014年 itcase. All rights reserved.
//

#import "YYViewController.h"

#define POTOIMGW    200
#define POTOIMGH    300
#define POTOIMGX    60
#define POTOIMGY    50

@interface YYViewController ()

@property(nonatomic,strong)NSArray *array;

-(void)change;
@property(nonatomic ,assign)int i;
@end

复制代码代码如下:

@implementation YYViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.i=0;
    //创建一个用来显示序号的lable控件
    UILabel *headlab=[[UILabel alloc]initWithFrame:CGRectMake(20, 10, 300, 30)];

// [headlab setText:@"1/5"];
    [headlab setTextAlignment:NSTextAlignmentCenter];
    [headlab setTextColor:[UIColor blackColor]];

    [self.view addSubview:headlab];
    self.firstlab=headlab;



    //创建一个装载图片的控件
    UIImageView *potoimg=[[UIImageView alloc]initWithFrame:CGRectMake(POTOIMGX, POTOIMGY, POTOIMGW, POTOIMGH)];

    UIImage *image=[UIImage imageNamed:@"biaoqingdi"];
    potoimg.image=image;

    [self.view addSubview:potoimg];
    self.icon=potoimg;

    //创建最下边的描述图片的lable控件
    UILabel *desclab=[[UILabel alloc]initWithFrame:CGRectMake(20, 400, 300, 30)];
   // [desclab setText:@"表情弱爆了！"];
    [desclab setTextAlignment:NSTextAlignmentCenter];
    [self.view addSubview:desclab];
    self.lastlab=desclab;


    //创建两个方向键按钮
    //设置为自定义类型
    //1.使用类创建对象
    UIButton *leftbtn=[UIButton buttonWithType:UIButtonTypeCustom];

    //2.设置对象的属性（不要忘记设置坐标）
    leftbtn.frame=CGRectMake(0, self.view.center.y, 40, 40);
    [leftbtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal];
    [leftbtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted];

    //3.提交对象到视图
    [self.view addSubview:leftbtn];

    self.leftbtn=leftbtn;
    [leftbtn addTarget:self action:@selector(leftclick:) forControlEvents:UIControlEventTouchUpInside];


    UIButton *rightbtn=[UIButton buttonWithType:UIButtonTypeCustom];

    rightbtn.frame=CGRectMake(POTOIMGX+POTOIMGW+10, self.view.center.y, 40, 40);
    [rightbtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal];
    [rightbtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted];

    [self.view addSubview:rightbtn];

    self.rightbtn=rightbtn;
    [rightbtn addTarget:self action:@selector(rightclick:) forControlEvents:UIControlEventTouchUpInside];
    [self change];
}

-(void)change
{
    self.icon.image=[UIImage imageNamed:self.array[self.i][@"name"]];
    self.lastlab.text=self.array[self.i][@"desc"];

    [self.firstlab setText:[NSString stringWithFormat:@"%d/5",self.i+1]];

    self.leftbtn.enabled=(self.i!=0);
    self.rightbtn.enabled=(self.i!=4);

}

//array的get方法
-(NSArray *)array
{
    NSLog(@"需要获取数组");
    //只实例化一次
    if (_array==nil) {

        NSString *path=[[NSBundle mainBundle] pathForResource:@"data" ofType:@"plist"];
        //数组的数据从文件获取
       // _array=[NSArray arrayWithContentsOfFile:path];
        _array=[[NSArray alloc]initWithContentsOfFile:path];
        //打印查看包的位置
        NSLog(@"%@",path);

       NSLog(@"实例化数组");
    }

return _array;
}

//向右按键
-(void)rightclick:(UIButton *)btn
{
self.i++;
[self change];
}

//向左按键
-(void)leftclick:(UIButton *)btn
{
self.i--;
[self change];
}

- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}

@end

（4）plist文件

201611392221000.png (868×338)