实现IOS开发中九宫格解锁技巧

//
// LockView.m
// 手势解锁
//
// Created by Daniel on 16/4/4.
// Copyright © 2016年 Daniel. All rights reserved.
//
 
 
#import "LockView.h"
 
@interface LockView ()
 
/** 保存已选中的按钮 */
@property(nonatomic, strong) NSMutableArray *selectedBtn;
/** 当前触摸点 */
@property(nonatomic, assign) CGPoint curp;
@end
 
@implementation LockView
 
- (NSMutableArray *)selectedBtn {
  if (_selectedBtn == nil) {
    _selectedBtn = [NSMutableArray array];
  }
  return _selectedBtn;
}
 
- (IBAction)pan:(UIPanGestureRecognizer *)pan {
   
  //获取当前触摸点
  _curp = [pan locationInView:self];
   
  //判断触摸点在不在按钮上
  for (UIButton *btn in self.subviews) {
    //如果在按钮上就设置选中状态
     
    //触摸点必须在button中心点30范围内才选中，更精确，体验更好
    CGRect rect = CGRectMake(btn.center.x, btn.center.y, 30, 30);
     
    if (CGRectContainsPoint(rect, _curp) && btn.selected == NO) {
      btn.selected = YES;
       
      //将这个选中的按钮保存起来
      [self.selectedBtn addObject:btn];
       
       
    }
  }
   
  //重绘，调用drawRect方法
  [self setNeedsDisplay];
   
  //手指抬起时
  if(pan.state == UIGestureRecognizerStateEnded) {
     
    NSMutableString *strM = [NSMutableString string];
     
    //如果当前触摸点不在Button上，则手指抬起时，就显示选中的Button以及连线
    UIButton *lastBtn = [self.selectedBtn lastObject];
     
    //把最后一个选中按钮的中心点设置为当前触摸点，清除最后多出来的一截连线
    _curp = lastBtn.center;
 
    for (UIButton *btn in self.selectedBtn) {
      //保存手势密码
      [strM appendFormat:@"%ld", btn.tag];
    }
     
    //strM就是密码了
    NSLog(@"%@",strM);
     
    //TODO：对比之前保存的密码，如果对了就直接跳转界面了
     
    //NSLog(@"手指抬起");
    //这里了执行完之后系统自动调用了重绘方法
     
    //等待2s后清除所有连线，清除Button的选中状态
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
      //取消按钮选中
      //[self.selectedBtn makeObjectsPerformSelector:@selector(setSelected:) withObject:NO];这句不知道为啥没有效果，只好用循环了
      for (UIButton *btn in self.selectedBtn) {
        [btn setSelected:NO];
      }
      //清除连线，清空选中按钮
      [self.selectedBtn removeAllObjects];
      [self setNeedsDisplay];
    });
     
  }
   
   
}
 
- (void)drawRect:(CGRect)rect {
 
  NSInteger count = self.selectedBtn.count;
   
  //如果没有按钮被选中，就不画线
  if (count == 0) {
    return;
  }
   
  UIBezierPath *path = [UIBezierPath bezierPath];
   
  //把所有点都连完线
  for (int i = 0; i