Quartz2D复习（二） --- 手势解锁

这次支付宝手机客户端升级，把手势解锁那个功能去掉了，引起很多人的抱怨，觉得少了手势解锁的保护，个人信息容易泄漏了。。。

那么手势解锁功能是怎么是实现的呢，这里使用Quart2D来简单模拟一下，

先看下截图效果：

         

按钮的有两个背景图片，一个默认样式，一个用于选中样式：

  

代码实现：

自定义view, 用来绘制所有路径，自定义view名称为：GestureLockView

GestureLockView.h文件：

#import <UIKit/UIKit.h>

@interface GestureLockView : UIView

@end

GestureLockView.m文件代码：

 //  手势解锁

 #import "GestureLockView.h"

 @interface GestureLockView()

 @property (nonatomic, retain) NSMutableArray *selectBtns;
 @property (nonatomic, assign) CGPoint moveP; //移动的点

 @end

 @implementation GestureLockView

 - (instancetype)initWithFrame:(CGRect)frame{
     if (self = [super initWithFrame:frame]){
         [self addBtns];
         NSLog(@"initWithFrame: %s", __func__);
     }
     return self;
 }

 //解析xib的时候调用
 - (instancetype)initWithCoder:(NSCoder *)aDecoder{
     if (self = [super initWithCoder:aDecoder]){
         NSLog(@"initWithCoder: %s", __func__);
         [self addBtns];
     }
     return self;
 }

 //添加子按钮
 - (void)addBtns{
     for (int i = ; i < ; i++) {
         UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
         [btn setBackgroundImage:[UIImage imageNamed:@"gesture_node_normal"] forState:UIControlStateNormal];
         [btn setBackgroundImage:[UIImage imageNamed:@"gesture_node_highlighted"] forState:UIControlStateSelected];
         [btn setUserInteractionEnabled:NO]; //设置不能和用户进行交互
         [btn setTag:i + ]; //设置标识
         [self addSubview:btn];
     }
 }

 - (NSMutableArray *)selectBtns{
     if (_selectBtns == nil){
         _selectBtns = [[NSMutableArray alloc] init];
     }
     return _selectBtns;
 }

 //触摸开始
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
     NSLog(@"触摸开始...");

     self.moveP = [self getPoint:touches];
     UIButton *btn = [self getBtn:self.moveP];

     if (btn != nil){
         [self.selectBtns addObject:btn];
         btn.selected = YES;
     }
 }

 //触摸移动, 设置被选中的按钮
 - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
     //NSLog(@"触摸移动");
     self.moveP = [self getPoint:touches];
     UIButton *btn = [self getBtn:self.moveP];

     if (btn != nil && btn.selected == NO){
         [self.selectBtns addObject:btn];
         btn.selected = YES;
     }

     [self setNeedsDisplay]; //从新绘制
 }

 //触摸结束，一切归空
 - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
     NSMutableString *str = [[NSMutableString alloc] init];
     for (UIButton * btn in self.selectBtns) {
         [str appendFormat:@"%i", btn.tag];
         btn.selected = NO;
     }

     self.moveP = CGPointZero;
     [self setNeedsDisplay];
     [self.selectBtns removeAllObjects];

 //    UILabel *lbl = [[UILabel alloc] init];
 //    lbl.text = [NSString stringWithFormat:@"密码是：%@", str];
 //    lbl.frame = CGRectMake(80, 150, 200, 30);
 //    [lbl setBackgroundColor:[UIColor whiteColor]];
 //    [lbl setTextAlignment:NSTextAlignmentCenter];
 //    [self addSubview:lbl];
 //
 //    [UIView animateWithDuration:5.0 animations:^{
 //        lbl.alpha = 0.1;
 //    } completion:^(BOOL finished) {
 //        [lbl removeFromSuperview];
 //    }];

     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"设置结果为" message:str delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
     [alert show];
 }

 //监听触摸移动，获取触摸坐标
 - (CGPoint)getPoint: (NSSet *)touches{
     UITouch *touch = [touches anyObject]; //获取当前接触点
     return [touch locationInView:self]; //获取当前触点在父对象中的位置
 }

 //根据坐标获取按钮对象
 - (UIButton *)getBtn: (CGPoint)point{
     for (UIButton * btn in self.subviews) {
         if (CGRectContainsPoint(btn.frame, point)){
             return btn;
         }
     }
     return nil;
 }

 //布局子控件的坐标位置
 - (void)layoutSubviews{
     CGFloat width = ;
     CGFloat height = width;
     CGFloat cols = ;
     CGFloat rows = cols;
     CGFloat margin = ([UIScreen mainScreen].bounds.size.width - width * cols) / (cols + );

     for (int i = ; i < rows; i++) {
         for (int j = ; j < cols; j++) {
             CGFloat x = j * (width + margin) + margin;
             CGFloat y = i * (height + margin) + margin;
             UIButton *btn = (UIButton *)[self.subviews objectAtIndex: (i * rows) + j];
             btn.frame = CGRectMake(x, y, width, height);
         }
     }
 }

 //
 // Only override drawRect: if you perform custom drawing.
 // An empty implementation adversely affects performance during animation.
 //从新绘制
 - (void)drawRect:(CGRect)rect {
     //1、获取当前上下文
     CGContextRef ctr = UIGraphicsGetCurrentContext();
     //2、绘制路径
     UIBezierPath *path = [UIBezierPath bezierPath];
     CGContextSetLineWidth(ctr, );  //设置线段宽度
     CGContextSetLineJoin(ctr, kCGLineJoinRound); //设置转折点
     [[UIColor whiteColor] set]; //设置路径颜色

     [path moveToPoint:self.moveP];

     for (int i = ; i < self.selectBtns.count; i++) {
         UIButton *btn = (UIButton *)[self.selectBtns objectAtIndex:i];
         CGPoint point = btn.center;

         if (i == ){
             [path moveToPoint:point];
         }
         else{
             [path addLineToPoint:point];
         }
     }

     if (!CGPointEqualToPoint(self.moveP, CGPointZero)){
         [path addLineToPoint:self.moveP]; //重点路径
     }
     //3、把路径添加到上下文中
     CGContextAddPath(ctr, path.CGPath);

     //4、渲染
     CGContextStrokePath(ctr);
 }

 @end

自定义控制器来展示自定义手势解锁view

GestureLockViewController.h :

#import <UIKit/UIKit.h>

@interface GestureLockViewController : UIViewController

@end

GestureLockViewController.m文件代码：

 #import "GestureLockViewController.h"
 #import "GestureLockView.h"

 @interface GestureLockViewController ()

 @end

 @implementation GestureLockViewController

 - (void)viewDidLoad {
     [super viewDidLoad];
     // Do any additional setup after loading the view.
     [self.view setBackgroundColor:[UIColor whiteColor]];

     //返回按钮
     UIButton *preBtn = [UIButton buttonWithType:UIButtonTypeCustom];
     [preBtn setFrame:CGRectMake(, , , )];
     [preBtn setBackgroundColor:[UIColor purpleColor]];
     [preBtn setTitle:@"返回" forState:UIControlStateNormal];
     [preBtn addTarget:self action:@selector(prePage) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:preBtn];

     //增加view
     CGSize size = [UIScreen mainScreen].bounds.size;
     GestureLockView *view = [[GestureLockView alloc] initWithFrame:CGRectMake(, , size.width, size.width + )];
     [view setBackgroundColor:[UIColor blackColor]];
     [self.view addSubview:view];
 }

 - (void)prePage{
     [self dismissViewControllerAnimated:YES completion:nil];
 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 /*
 #pragma mark - Navigation

 // In a storyboard-based application, you will often want to do a little preparation before navigation
 - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
     // Get the new view controller using [segue destinationViewController].
     // Pass the selected object to the new view controller.
 }
 */

 @end