@property (nonatomic,strong)NSMutableArray *buttonArr;//全部手势按键的数组

 @property (nonatomic,strong)NSMutableArray *selectorArr;//选中手势按键的数组

 @property (nonatomic,assign)CGPoint startPoint;//记录开始选中的按键坐标

 @property (nonatomic,assign)CGPoint endPoint;//记录结束时的手势坐标

 @property (nonatomic,strong)UIImageView *imageView;//画图所需

 -(NSMutableArray *)selectorArr

 {

     if (!_selectorArr) {

         _selectorArr = [[NSMutableArray alloc]init];

     }

     return _selectorArr;

 }

 - (void)viewDidLoad {

     [super viewDidLoad];

     self.view.backgroundColor = [UIColor whiteColor];

     if (!_buttonArr) {

         _buttonArr = [[NSMutableArray alloc]initWithCapacity:];

     }

     self.imageView = [[UIImageView alloc]initWithFrame:CGRectMake(, , ScreenWidth, ScreenHeight)];

     [self.view addSubview:self.imageView];

     for (int i=; i<; i++) {

         for (int j=; j<; j++) {

             UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];

             btn.frame = CGRectMake(ScreenWidth/+ScreenWidth/*j, ScreenHeight/+ScreenWidth/*i, ScreenWidth/, ScreenWidth/);

             [btn setImage:[UIImage imageNamed:@"pbg"] forState:UIControlStateNormal];

             [btn setImage:[UIImage imageNamed:@"pbg01"] forState:UIControlStateHighlighted];

             btn.userInteractionEnabled = NO;

             [self.buttonArr addObject:btn];

             [self.imageView addSubview:btn];

         }

     }

 }

 -(UIImage *)drawLine{

     UIImage *image = nil;

     UIColor *col = [UIColor colorWithRed: green: blue: alpha:];

     UIGraphicsBeginImageContext(self.imageView.frame.size);//设置画图的大小为imageview的大小

     CGContextRef context = UIGraphicsGetCurrentContext();

     CGContextSetLineWidth(context, );

     CGContextSetStrokeColorWithColor(context, col.CGColor);

     CGContextMoveToPoint(context, self.startPoint.x, self.startPoint.y);//设置画线起点

     //从起点画线到选中的按键中心，并切换画线的起点

     for (UIButton *btn in self.selectorArr) {

         CGPoint btnPo = btn.center;

         CGContextAddLineToPoint(context, btnPo.x, btnPo.y);

         CGContextMoveToPoint(context, btnPo.x, btnPo.y);

     }

     //画移动中的最后一条线

     CGContextAddLineToPoint(context, self.endPoint.x, self.endPoint.y);

     CGContextStrokePath(context);

     image = UIGraphicsGetImageFromCurrentImageContext();//画图输出

     UIGraphicsEndImageContext();//结束画线

     return image;

 }

 //开始手势

 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

 {

     UITouch *touch = [touches anyObject];//保存所有触摸事件

     if (touch) {

         for (UIButton *btn in self.buttonArr) {

             CGPoint po = [touch locationInView:btn];//记录按键坐标

             if ([btn pointInside:po withEvent:nil]) {//判断按键坐标是否在手势开始范围内,是则为选中的开始按键

                 [self.selectorArr addObject:btn];

                 btn.highlighted = YES;

                 self.startPoint = btn.center;//保存起始坐标

             }

         }

     }

 }

 //移动中触发，画线过程中会一直调用画线方法

 -(void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

 {

     UITouch *touch = [touches anyObject];

     if (touch) {

         self.endPoint = [touch locationInView:self.imageView];

         for (UIButton *btn in self.buttonArr) {

             CGPoint po = [touch locationInView:btn];

             if ([btn pointInside:po withEvent:nil]) {

                 BOOL isAdd = YES;//记录是否为重复按键

                 for (UIButton *seBtn in self.selectorArr) {

                     if (seBtn == btn) {

                         isAdd = NO;//已经是选中过的按键，不再重复添加

                         break;

                     }

                 }

                 if (isAdd) {//未添加的选中按键，添加并修改状态

                     [self.selectorArr addObject:btn];

                     btn.highlighted = YES;

                 }

             }

         }

     }

     self.imageView.image = [self drawLine];//每次移动过程中都要调用这个方法，把画出的图输出显示

 }

 //手势结束触发

 -(void)touchesEnded:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event

 {

     self.imageView.image = nil;

     self.selectorArr = nil;

     for (UIButton *btn in self.buttonArr) {

         btn.highlighted = NO;

     }

 }