一、程序实现要求
1.要求
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
1 // 2 // SLViewController.m 3 // 03-图片浏览器初步 4 // 5 // Created by apple on 14-5-21. 6 // Copyright (c) 2014年 itcase. All rights reserved. 7 // 8 9 #import "SLViewController.h" 10 11 #define PHOTOIMGW 200 12 #define PHOTOIMGH 300 13 #define PHOTOIMGX 60 14 #define PHOTOIMGY 50 15 16 17 @interface SLViewController () 18 19 // 变量声明 20 @property(nonatomic, strong)UILabel *firstLab; 21 @property(nonatomic, strong)UILabel *lastLab; 22 @property(nonatomic, strong)UIImageView *icon; 23 @property(nonatomic, strong)UIButton *leftBtn; 24 @property(nonatomic, strong)UIButton *rightBtn; 25 26 -(void)change; 27 @property(nonatomic, assign) int i; 28 @end 29 30 @implementation SLViewController 31 32 - (void)viewDidLoad 33 { 34 [super viewDidLoad]; 35 self.i = 0; 36 // 创建一个用来显示序号的lable控件 37 UILabel *headLab = [[UILabel alloc]initWithFrame:CGRectMake(20, 10, 300, 30)]; 38 39 // [headLab setText:@"1/5"]; 40 [headLab setTextAlignment:NSTextAlignmentCenter]; 41 [headLab setTextColor:[UIColor blackColor]]; 42 43 [self.view addSubview:headLab]; 44 self.firstLab = headLab; 45 46 // 创建一个装载图片的控件 47 UIImageView *photoImg = [[UIImageView alloc]initWithFrame:CGRectMake(PHOTOIMGX, PHOTOIMGY, PHOTOIMGW, PHOTOIMGH)]; 48 49 UIImage *image = [UIImage imageNamed:@"biaoqingdi"]; 50 photoImg.image = image; 51 52 [self.view addSubview:photoImg]; 53 self.icon = photoImg; 54 55 56 57 // 创建最下边的描述图片的lable控件 58 UILabel *descLab = [[UILabel alloc]initWithFrame:CGRectMake(20, 400, 300, 30)]; 59 // [descLab setText:@"表情弱爆了!"]; 60 [descLab setTextAlignment:NSTextAlignmentCenter]; 61 [self.view addSubview:descLab]; 62 self.lastLab = descLab; 63 64 65 // 创建两个方向键按钮 66 // 设置为自定义类型 67 // 1.使用类创建对象 68 UIButton *leftBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 69 70 // 2.设置对象的属性(不要忘记设置坐标) 71 leftBtn.frame = CGRectMake(0, self.view.center.y, 40, 40); 72 [leftBtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal]; 73 [leftBtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted]; 74 75 // 3.提交对象到视图 76 [self.view addSubview:leftBtn]; 77 78 self.leftBtn = leftBtn; 79 [leftBtn addTarget:self action:@selector(leftclick:) forControlEvents:UIControlEventTouchUpInside]; 80 81 82 UIButton *rightBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 83 84 rightBtn.frame = CGRectMake(PHOTOIMGX+PHOTOIMGW+10, self.view.center.y, 40, 40); 85 [rightBtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal]; 86 [rightBtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted]; 87 88 [self.view addSubview:rightBtn]; 89 90 self.rightBtn = rightBtn; 91 [rightBtn addTarget:self action:@selector(rightclick:) forControlEvents:UIControlEventTouchUpInside]; 92 93 // 这是一个初始化方法,调用change可以完成初始化的工作 94 [self change]; 95 } 96 97 -(void)change 98 { 99 [self.firstLab setText:[NSString stringWithFormat:@"%d/5",self.i + 1]];100 switch (self.i) {101 case 0:102 self.lastLab.text = @"什么表情都弱爆了!";103 self.icon.image = [UIImage imageNamed:@"biaoqingdi"];104 break;105 case 1:106 self.lastLab.text = @"病例";107 self.icon.image = [UIImage imageNamed:@"bingli"];108 break;109 case 2:110 self.lastLab.text = @"王八";111 self.icon.image = [UIImage imageNamed:@"wangba"];112 break;113 case 3:114 self.lastLab.text = @"吃牛扒";115 self.icon.image = [UIImage imageNamed:@"chiniupa"];116 break;117 case 4:118 self.lastLab.text = @"蛋疼!";119 self.icon.image = [UIImage imageNamed:@"danteng"];120 break;121 }122 // 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123 self.leftBtn.enabled = (self.i != 0);124 self.rightBtn.enabled = (self.i != 4);125 126 }127 128 // 向右按键129 -(void)rightclick:(UIButton *)btn130 {131 self.i++;132 [self change];133 // NSLog(@"点我了");134 }135 -(void)leftclick:(UIButton *)btn136 {137 self.i--;138 [self change];139 }140 141 @end
三、程序优化
1 // 2 // SLViewController.m 3 // 03-图片浏览器初步 4 // 5 // Created by apple on 14-5-21. 6 // Copyright (c) 2014年 itcase. All rights reserved. 7 // 8 9 #import "SLViewController.h" 10 11 #define PHOTOIMGW 200 12 #define PHOTOIMGH 300 13 #define PHOTOIMGX 60 14 #define PHOTOIMGY 50 15 16 17 @interface SLViewController () 18 19 // 变量声明 20 @property(nonatomic, strong)UILabel *firstLab; 21 @property(nonatomic, strong)UILabel *lastLab; 22 @property(nonatomic, strong)UIImageView *icon; 23 @property(nonatomic, strong)UIButton *leftBtn; 24 @property(nonatomic, strong)UIButton *rightBtn; 25 26 @property(nonatomic,strong)NSArray *array; 27 28 -(void)change; 29 @property(nonatomic, assign) int i; 30 @end 31 32 @implementation SLViewController 33 34 - (void)viewDidLoad 35 { 36 [super viewDidLoad]; 37 self.i = 0; 38 // 创建一个用来显示序号的lable控件 39 UILabel *headLab = [[UILabel alloc]initWithFrame:CGRectMake(20, 10, 300, 30)]; 40 41 // [headLab setText:@"1/5"]; 42 [headLab setTextAlignment:NSTextAlignmentCenter]; 43 [headLab setTextColor:[UIColor blackColor]]; 44 45 [self.view addSubview:headLab]; 46 self.firstLab = headLab; 47 48 // 创建一个装载图片的控件 49 UIImageView *photoImg = [[UIImageView alloc]initWithFrame:CGRectMake(PHOTOIMGX, PHOTOIMGY, PHOTOIMGW, PHOTOIMGH)]; 50 51 UIImage *image = [UIImage imageNamed:@"biaoqingdi"]; 52 photoImg.image = image; 53 54 [self.view addSubview:photoImg]; 55 self.icon = photoImg; 56 57 58 59 // 创建最下边的描述图片的lable控件 60 UILabel *descLab = [[UILabel alloc]initWithFrame:CGRectMake(20, 400, 300, 30)]; 61 // [descLab setText:@"表情弱爆了!"]; 62 [descLab setTextAlignment:NSTextAlignmentCenter]; 63 [self.view addSubview:descLab]; 64 self.lastLab = descLab; 65 66 67 // 创建两个方向键按钮 68 // 设置为自定义类型 69 // 1.使用类创建对象 70 UIButton *leftBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 71 72 // 2.设置对象的属性(不要忘记设置坐标) 73 leftBtn.frame = CGRectMake(0, self.view.center.y, 40, 40); 74 [leftBtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal]; 75 [leftBtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted]; 76 77 // 3.提交对象到视图 78 [self.view addSubview:leftBtn]; 79 80 self.leftBtn = leftBtn; 81 [leftBtn addTarget:self action:@selector(leftclick:) forControlEvents:UIControlEventTouchUpInside]; 82 83 84 UIButton *rightBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 85 86 rightBtn.frame = CGRectMake(POTOIMGX+POTOIMGW+10, self.view.center.y, 40, 40); 87 [rightBtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal]; 88 [rightBtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted]; 89 90 [self.view addSubview:rightBtn]; 91 92 self.rightBtn = rightBtn; 93 [rightBtn addTarget:self action:@selector(rightclick:) forControlEvents:UIControlEventTouchUpInside]; 94 /* 95 // 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 96 NSDictionary *dict1 = @{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了!"}; 97 NSDictionary *dict2 = @{@"name": @"bingli",@"desc":@"病例"}; 98 NSDictionary *dict3 = @{@"name": @"wangba",@"desc":@"乌龟"}; 99 NSDictionary *dict4 = @{@"name": @"chiniupa",@"desc":@"吃牛扒"};100 NSDictionary *dict5 = @{@"name": @"danteng",@"desc":@"蛋疼"};101 102 self.array = @[dict1,dict2,dict3,dict4,dict5];103 */104 105 // 这是一个初始化方法,调用change可以完成初始化的工作106 [self change];107 }108 109 -(void)change110 {111 /*112 // 每次调用都需要创建?有没有什么解决办法?113 NSDictionary *dict1 = @{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了!"};114 NSDictionary *dict2 = @{@"name": @"bingli",@"desc":@"病例"};115 NSDictionary *dict3 = @{@"name": @"wangba",@"desc":@"乌龟"};116 NSDictionary *dict4 = @{@"name": @"chiniupa",@"desc":@"吃牛扒"};117 NSDictionary *dict5 = @{@"name": @"danteng",@"desc":@"蛋疼"};118 119 NSArray *array = @[dict1,dict2,dict3,dict4,dict5];120 */121 122 /*123 //设置照片124 //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125 self.icon.image = [UIImage imageNamed:array[self.i][@"name"]];126 self.lastLab.text = array[self.i][@"desc"];127 NSLog(@"%@",array[self.i][@"desc"]);128 */129 130 self.icon.image = [UIImage imageNamed:self.array[self.i][@"name"]];131 self.lastLab.text = self.array[self.i][@"desc"];132 133 [self.firstLab setText:[NSString stringWithFormat:@"%d/5",self.i + 1]];134 135 136 /*137 switch (self.i) {138 case 0:139 self.lastLab.text = @"什么表情都弱爆了!";140 self.icon.image = [UIImage imageNamed:@"biaoqingdi"];141 break;142 case 1:143 self.lastLab.text = @"病例";144 self.icon.image = [UIImage imageNamed:@"bingli"];145 break;146 case 2:147 self.lastLab.text = @"王八";148 self.icon.image = [UIImage imageNamed:@"wangba"];149 break;150 case 3:151 self.lastLab.text = @"吃牛扒";152 self.icon.image = [UIImage imageNamed:@"chiniupa"];153 break;154 case 4:155 self.lastLab.text = @"蛋疼!";156 self.icon.image = [UIImage imageNamed:@"danteng"];157 break;158 }159 */160 161 // 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162 self.leftBtn.enabled = (self.i != 0);163 self.rightBtn.enabled = (self.i != 4);164 165 }166 167 //array的get方法168 -(NSArray *)array169 {170 NSLog(@"需要获取数组");171 //只实例化一次172 if (_array == nil) {173 NSLog(@"实例化数组");174 NSDictionary *dict1 = @{ @"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了!"};175 NSDictionary *dict2 = @{ @"name": @"bingli",@"desc":@"病例"};176 NSDictionary *dict3 = @{ @"name": @"wangba",@"desc":@"乌龟"};177 NSDictionary *dict4 = @{ @"name": @"chiniupa",@"desc":@"吃牛扒"};178 NSDictionary *dict5 = @{ @"name": @"danteng",@"desc":@"蛋疼"};179 _array=@[dict1, dict2, dict3, dict4, dict5];180 }181 /*182 NSDictionary *dict1 = @{@"name": @"biaoqingdi",@"desc":@"什么表情都弱爆了!"};183 NSDictionary *dict2 = @{@"name": @"bingli",@"desc":@"病例"};184 NSDictionary *dict3 = @{@"name": @"wangba",@"desc":@"乌龟"};185 NSDictionary *dict4 = @{@"name": @"chiniupa",@"desc":@"吃牛扒"};186 NSDictionary *dict5 = @{@"name": @"danteng",@"desc":@"蛋疼"};187 _array=@[dict1, dict2, dict3, dict4, dict5];188 */189 return _array;190 }191 192 // 向右按键193 -(void)rightclick:(UIButton *)btn194 {195 self.i++;196 [self change];197 }198 -(void)leftclick:(UIButton *)btn199 {200 self.i--;201 [self change];202 }203 204 @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:
@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:
1 - (UIImageView *)icon 2 { 3 4 if (!_icon) { 5 6 // 计算位置参数 7 8 CGFloat imageW = 200; 9 10 CGFloat imageX = (320 - imageW) / 2;11 12 CGFloat imageH = 200;13 14 CGFloat imageY = 80;15 16 // 实例化图像视图17 18 _icon = [[UIImageView alloc] initWithFrame:CGRectMake(imageX, imageY, imageW, imageH)];19 20 // 将图像视图添加到主视图21 22 [self.view addSubview:_icon];23 24 }25 26 return _icon;27 28 }
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:
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
1 // 2 // SLViewController.m 3 // 03-图片浏览器初步 4 // 5 // Created by apple on 14-5-21. 6 // Copyright (c) 2014年 itcase. All rights reserved. 7 // 8 9 #import "SLViewController.h" 10 11 #define PHOTOIMGW 200 12 #define PHOTOIMGH 300 13 #define PHOTOIMGX 60 14 #define PHOTOIMGY 50 15 16 17 @interface SLViewController () 18 19 // 变量声明 20 @property(nonatomic, strong)UILabel *firstLab; 21 @property(nonatomic, strong)UILabel *lastLab; 22 @property(nonatomic, strong)UIImageView *icon; 23 @property(nonatomic, strong)UIButton *leftBtn; 24 @property(nonatomic, strong)UIButton *rightBtn; 25 26 @property(nonatomic,strong)NSArray *array; 27 28 -(void)change; 29 @property(nonatomic, assign) int i; 30 @end 31 32 @implementation SLViewController 33 34 - (void)viewDidLoad 35 { 36 [super viewDidLoad]; 37 self.i = 0; 38 // 创建一个用来显示序号的lable控件 39 UILabel *headLab = [[UILabel alloc] initWithFrame:CGRectMake(20, 10, 300, 30)]; 40 41 // [headLab setText:@"1/5"]; 42 [headLab setTextAlignment:NSTextAlignmentCenter]; 43 [headLab setTextColor:[UIColor blackColor]]; 44 45 [self.view addSubview:headLab]; 46 self.firstLab = headLab; 47 48 // 创建一个装载图片的控件 49 UIImageView *photoImg = [[UIImageView alloc]initWithFrame:CGRectMake(PHOTOIMGX, PHOTOIMGY, PHOTOIMGW, PHOTOIMGH)]; 50 51 UIImage *image = [UIImage imageNamed:@"biaoqingdi"]; 52 photoImg.image = image; 53 54 [self.view addSubview:photoImg]; 55 self.icon = photoImg; 56 57 58 59 // 创建最下边的描述图片的lable控件 60 UILabel *descLab = [[UILabel alloc] initWithFrame:CGRectMake(20, 400, 300, 30)]; 61 // [descLab setText:@"表情弱爆了!"]; 62 [descLab setTextAlignment:NSTextAlignmentCenter]; 63 [self.view addSubview:descLab]; 64 self.lastLab = descLab; 65 66 67 // 创建两个方向键按钮 68 // 设置为自定义类型 69 // 1.使用类创建对象 70 UIButton *leftBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 71 72 // 2.设置对象的属性(不要忘记设置坐标) 73 leftBtn.frame = CGRectMake(0, self.view.center.y, 40, 40); 74 [leftBtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal]; 75 [leftBtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted]; 76 77 // 3.提交对象到视图 78 [self.view addSubview:leftBtn]; 79 80 self.leftBtn = leftBtn; 81 [leftBtn addTarget:self action:@selector(leftclick:) forControlEvents:UIControlEventTouchUpInside]; 82 83 84 UIButton *rightBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 85 86 rightBtn.frame = CGRectMake(POTOIMGX+POTOIMGW+10, self.view.center.y, 40, 40); 87 [rightBtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal]; 88 [rightBtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted]; 89 90 [self.view addSubview:rightBtn]; 91 92 self.rightBtn = rightBtn; 93 [rightBtn addTarget:self action:@selector(rightclick:) forControlEvents:UIControlEventTouchUpInside]; 94 95 // 这是一个初始化方法,调用change可以完成初始化的工作 96 [self change]; 97 } 98 99 -(void)change100 {101 102 self.icon.image=[UIImage imageNamed:self.array[self.i][@"name"]];103 self.lastLab.text=self.array[self.i][@"desc"];104 105 [self.firstLab setText:[NSString stringWithFormat:@"%d/5",self.i + 1]];106 107 // 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108 self.leftBtn.enabled = (self.i != 0);109 self.rightBtn.enabled = (self.i != 4);110 111 }112 113 // array的get方法114 -(NSArray *)array115 {116 NSLog(@"需要获取数组");117 // 只实例化一次118 if (_array==nil) {119 120 NSString *path=[[NSBundle mainBundle] pathForResource:@"data" ofType:@"plist"];121 // 数组的数据从文件获取122 // _array=[NSArray arrayWithContentsOfFile:path];123 _array=[[NSArray alloc]initWithContentsOfFile:path];124 // 打印查看包的位置125 NSLog(@"%@",path);126 127 NSLog(@"实例化数组");128 }129 return _array;130 }131 132 // 向右按键133 -(void)rightclick:(UIButton *)btn134 {135 self.i++;136 [self change];137 }138 -(void)leftclick:(UIButton *)btn139 {140 self.i--;141 [self change];142 }143 144 @end
(4)plist文件
(5)实现效果
五、补充
开发思路:
1.完成基本功能
2.考虑性能
(1)(初始化操作,可以直接调用change进行)
(2)因为要控制序号和图片两个变量,所以考虑使用字典代替掉switch
(3)每次点击,字典都需要创建一次,效率低,可以考虑创建的这部分拿到初始化方法中去,这样就只需要创建一次就ok了。
(4)考虑缺点(对代码的顺序要求极其严格)
(5)懒加载(需要的时候才加载,那么什么时候是需要的时候,及调用get方法的时候)
(6)每次都来一下?效率低 → 只有第一次调用get方法时为空,此时实例化并建立数组,其他时候直接返回成员变量(仅仅执行一次)
注意点:
1.方法的调用堆栈(顺序)。
2.使用plist:让数据的操作更加灵活,把数据弄到外面去,解除耦合性,让耦合性不要太强。实际上是一个xml,是苹果定义的一种特殊格式的xml。
3.bundle-包(只读)