ios实现简单的查看器

用纯代码开发的过程

1.了解界面是由什么构成的

2.用代码创建界面

3.编写代码

**

首先就是搭建界面了

//界面加载完时调用
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
//1.序号
_noLable=[[UILabel alloc]initWithFrame:CGRectMake(0, 20.0, self.view.bounds.size.width, 40.0)];
// _noLable.text=@"1/5";
[self.view addSubview:_noLable];
// 设置lable文字的位置
_noLable.textAlignment=NSTextAlignmentCenter;
//2.图片
CGFloat imageW=200.0;
CGFloat imageH=200.0;
CGFloat imageX=(self.view.bounds.size.width-imageW)*0.5;
CGFloat imageY=CGRectGetMaxY(self.noLable.frame)+20.0;
_iconView=[[UIImageView alloc]initWithFrame:CGRectMake(imageX, imageY, imageW,imageH)];
//[_iconView setBackgroundColor:[UIColor purpleColor]];
_iconView.image=[UIImage imageNamed:@"biaoqingdi"];
[self.view addSubview:_iconView];
//3.设置图片介绍
CGFloat descY=CGRectGetMaxY(_iconView.frame);
_descLable =[[UILabel alloc]initWithFrame:CGRectMake(0.0, descY, self.view.bounds.size.width, 40.0)];
// _descLable.text=@"这是什么表情啊？";
_descLable.textAlignment=NSTextAlignmentCenter;
[_descLable setBackgroundColor:[UIColor yellowColor]];
[self.view addSubview:_descLable];
//4.设置左边的按钮

_leftBtn=[[UIButton alloc]initWithFrame:CGRectMake(0, 0, 40.0, 40.0)];
CGFloat centerY=self.iconView.center.y;
CGFloat centerX=(self.iconView.frame.origin.x*0.5);
_leftBtn.center=CGPointMake(centerX,centerY);

_leftBtn.tag=-1;

[_leftBtn setBackgroundImage:[UIImage imageNamed:@"left_normal"] forState:UIControlStateNormal];
[_leftBtn setBackgroundImage:[UIImage imageNamed:@"left_highlighted"] forState:UIControlStateHighlighted];
[_leftBtn setBackgroundImage:[UIImage imageNamed:@"left_disable"] forState:UIControlStateDisabled];
[_leftBtn addTarget:self action:@selector(clickBtn:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:_leftBtn];

//5.设置右边的按钮
_rightBtn=[[UIButton alloc]initWithFrame:CGRectMake(0, 0, 40.0, 40.0)];
_rightBtn.center=CGPointMake(self.view.bounds.size.width-centerX, centerY);
[_rightBtn setBackgroundImage:[UIImage imageNamed:@"right_normal"] forState:UIControlStateNormal];
[_rightBtn setBackgroundImage:[UIImage imageNamed:@"right_highlighted"] forState:UIControlStateHighlighted];
[_rightBtn setBackgroundImage:[UIImage imageNamed:@"right_disable"] forState:UIControlStateDisabled];
[self.view addSubview:_rightBtn];
_rightBtn.tag=+1;
[_rightBtn addTarget:self action:@selector(clickBtn:) forControlEvents:UIControlEventTouchUpInside];
[self ShowPhotoInfo];

}

现在就是实现功能了

代码1:

//实现方法 下一张照片
//-(void)nextPhoto{
//    //NSLog(@"%s",__func__);
//    self.index++;
//    [self ShowPhotoInfo];
//}
///*上一张照片*/
//-(void)topPhoto{
//    self.index--;
//    [self ShowPhotoInfo];
//    // 设置序号
//    self.noLable.text = [NSString stringWithFormat:@"%d/%d", self.index +1, 5];
//    switch (self.index) {
//        case 0:
//            self.iconView.image=[UIImage imageNamed:@"biaoqingdi"];
//            self.descLable.text=@"这个表情已经无人能敌了！";
//            break;
//        case 1:
//            self.iconView.image=[UIImage imageNamed:@"bingli"];
//            self.descLable.text=@"病例";
//            break;
//        case 2:
//            self.iconView.image=[UIImage imageNamed:@"chiniupa"];
//            self.descLable.text=@"小妹妹你这吃牛扒可比杀牛费劲啊！";
//            break;
//        case 3:
//            self.iconView.image=[UIImage imageNamed:@"danteng"];
//            self.descLable.text=@"真心蛋疼啊！";
//            break;
//        case 4:
//            self.iconView.image=[UIImage imageNamed:@"wangba"];
//            self.descLable.text=@"哦哦！我科打铁美如画。。。";
//            break;
//    }
//        self.leftBtn.enabled=(self.index!=0);
//    NSLog(@"llll");
//
//}

代码2

/*代码的重构意思就是让重复的代码只出现一次*/
-(void)ShowPhotoInfo{
// 设置序号
self.noLable.text = [NSString stringWithFormat:@"%d/%d", self.index +1, 5];
switch (self.index) {
case 0:
self.iconView.image=[UIImage imageNamed:@"biaoqingdi"];
self.descLable.text=@"这个表情已经无人能敌了！";
break;
case 1:
self.iconView.image=[UIImage imageNamed:@"bingli"];
self.descLable.text=@"病例";
break;
case 2:
self.iconView.image=[UIImage imageNamed:@"chiniupa"];
self.descLable.text=@"小妹妹你这吃牛扒可比杀牛费劲啊！";
break;
case 3:
self.iconView.image=[UIImage imageNamed:@"danteng"];
self.descLable.text=@"真心蛋疼啊！";
break;
case 4:
self.iconView.image=[UIImage imageNamed:@"wangba"];
self.descLable.text=@"哦哦！我科打铁美如画。。。";
break;
}
self.leftBtn.enabled=(self.index!=0);
self.rightBtn.enabled=(self.index!=4);
// NSLog(@"llll");
}

-(void) clickBtn:(UIButton *)button{

//获取图片索引?
self.index+=(int)button.tag;
[self ShowPhotoInfo];
}

值得注意的

我们在些代码的时候首先不是写最好的代码，而是要先把功能给实现了，在实现功能之后再修改，整合代码。

可以采取NSLog来看数据是否输出正确，当然用断点调试就更好了。