iOS学习方法练习

很多APP都要用的如tabelView
新版本@synthesize window = _window;

image.png

练习

• 1、在松手的时候判断哪张图片在左视图还是右视图
• 2、拖入imageView数组到View视图中转换坐标然后label计数
• 3、点击图片删除时添加了手势即必须打开用户交互功能实现

• 4、删除图片后label计数也相应减少
  以下是代码

  
  image.png

#import "ViewController.h"
@interface ViewController ()
@property (strong, nonatomic) IBOutletCollection(UIImageView) NSArray *imageViews;
@property (weak, nonatomic) IBOutlet UILabel *leftLabel;
@property (weak, nonatomic) IBOutlet UILabel *rightLabel;
@property (weak, nonatomic) IBOutlet UIView *leftView;
@property (weak, nonatomic) IBOutlet UIView *rightView;
@property(nonatomic,strong)UIImageView *dragIV;
@end

@implementation ViewController
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    UITouch *t = [touches anyObject];
    CGPoint p = [t locationInView:self.view];
    //判断p点 点击的是哪个图片
    for(UIImageView *iv in self.imageViews){
        if (CGRectContainsPoint(iv.frame, p)) {
            //removeFromSuperview移除控件
            //[iv removeFromSuperview];
            UIImageView *dragIV = [[UIImageView alloc]initWithFrame:iv.frame];
            dragIV.image = iv.image;
            [self.view addSubview:dragIV];
            self.dragIV = dragIV;
            //imageView的交互要打来手势方法才能执行
            dragIV.userInteractionEnabled = YES;
            //创建点击手势
            UITapGestureRecognizer *tap =[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapAction:)];
            [dragIV addGestureRecognizer:tap];
        }
    }
}
-(void)tapAction:(UITapGestureRecognizer*)tap{
    if([tap.view.superview isEqual:self.leftView]){
        //把点击的view删除
        [tap.view removeFromSuperview];
        self.leftLabel.text = @(self.leftView.subviews.count).stringValue;
        
    }else{
        //把点击的view删除
        [tap.view removeFromSuperview];
        self.rightLabel.text = @(self.rightView.subviews.count).stringValue;
    }
}
-(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    UITouch *t = [touches anyObject];
    CGPoint p = [t locationInView:self.view];
    self.dragIV.center = p;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}
-(void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    if (CGRectContainsPoint(self.leftView.frame, self.dragIV.center)) {
        //得到相对于self.view的点
        CGPoint oldCenter = self.dragIV.center;
        //把相对于self.view的点转换成相对于leftView的点
        CGPoint newCenter = [self.view convertPoint:oldCenter toView:self.leftView];
        [self.leftView addSubview:self.dragIV];
        self.dragIV.center = newCenter;
        self.leftLabel.text = @(self.leftView.subviews.count).stringValue;
        
    }else if(CGRectContainsPoint(self.rightView.frame, self.dragIV.center)) {
        CGPoint oldCenter = self.dragIV.center;
        //把相对于self.view的点转换成相对于leftView的点
        CGPoint newCenter = [self.view convertPoint:oldCenter toView:self.rightView];
        
        [self.rightView addSubview:self.dragIV];
        self.dragIV.center = newCenter;
        self.rightLabel.text = @(self.rightView.subviews.count).stringValue;
        
    }else{//没有在view里松手
        [self.dragIV removeFromSuperview];
    }
    self.dragIV = nil;
    
}