ScreenUnLock 与智能手机上的图案解锁功能一样。通过绘制图形达到解锁或记忆图形的目的。
本人突发奇想，把手机上的图形解锁功能移植到WPF中。也应用到了公司的项目中。
在创建ScreenUnLock之前，先来分析一下图形解锁的实现思路。
1.创建九宫格原点(或更多格子)，每个点定义一个坐标值
2.提供图形解锁相关扩展属性和事件，方便调用者定义。比如：点和线的颜色(Color)，操作模式(Check|Remember)，验证正确的颜色(RightColor), 验证失败的颜色(ErrorColor), 解锁事件 OnCheckedPoint，记忆事件 OnRememberPoint 等;
3.定义MouseMove事件监听画线行为。 画线部分也是本文的核心。在画线过程中。程序需判断，线条从哪个点开始绘制，经过了哪个点(排除已经记录的点)。是否完成了绘制等等。
4.画线完成，根据操作模式处理画线完成行为。并调用相关自定义事件
大致思路如上，下面开始一步一步编写ScreenUnLock吧
创建ScreenUnLock
public partial class ScreenUnlock : UserControl
定义相关属性
1 /// <summary>
2 /// 验证正确的颜色
3 /// </summary>
4 private SolidColorBrush rightColor;
5
6 /// <summary>
7 /// 验证失败的颜色
8 /// </summary>
9 private SolidColorBrush errorColor;
10
11 /// <summary>
12 /// 图案是否在检查中
13 /// </summary>
14 private bool isChecking;
15
16 public static readonly DependencyProperty PointArrayProperty = DependencyProperty.Register("PointArray", typeof(IList<string>), typeof(ScreenUnlock));
17 /// <summary>
18 /// 记忆的坐标点
19 /// </summary>
20 public IList<string> PointArray
21 {
22 get { return GetValue(PointArrayProperty) as IList<string>; }
23 set { SetValue(PointArrayProperty, value); }
24 }
25
26 /// <summary>
27 /// 当前坐标点集合
28 /// </summary>
29 private IList<string> currentPointArray;
30
31 /// <summary>
32 /// 当前线集合
33 /// </summary>
34 private IList<Line> currentLineList;
35
36 /// <summary>
37 /// 点集合
38 /// </summary>
39 private IList<Ellipse> ellipseList;
40
41 /// <summary>
42 /// 当前正在绘制的线
43 /// </summary>
44 private Line currentLine;
45
46 public static readonly DependencyProperty OperationPorperty = DependencyProperty.Register("Operation", typeof(ScreenUnLockOperationType), typeof(ScreenUnlock), new FrameworkPropertyMetadata(ScreenUnLockOperationType.Remember));
47 /// <summary>
48 /// 操作类型
49 /// </summary>
50 public ScreenUnLockOperationType Operation
51 {
52 get { return (ScreenUnLockOperationType)GetValue(OperationPorperty); }
53 set { SetValue(OperationPorperty, value); }
54 }
55
56 public static readonly DependencyProperty PointSizeProperty = DependencyProperty.Register("PointSize", typeof(double), typeof(ScreenUnlock), new FrameworkPropertyMetadata(15.0));
57 /// <summary>
58 /// 坐标点大小
59 /// </summary>
60 public double PointSize
61 {
62 get { return Convert.ToDouble(GetValue(PointSizeProperty)); }
63 set { SetValue(PointSizeProperty, value); }
64 }
65
66
67 public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(SolidColorBrush), typeof(ScreenUnlock), new FrameworkPropertyMetadata(new SolidColorBrush(Colors.White), new PropertyChangedCallback((s, e) =>
68 {
69 (s as ScreenUnlock).Refresh();
70 })));
71
72 /// <summary>
73 /// 坐标点及线条颜色
74 /// </summary>
75 public SolidColorBrush Color
76 {
77 get { return GetValue(ColorProperty) as SolidColorBrush; }
78 set { SetValue(ColorProperty, value); }
79 }
/// <summary>
/// 操作类型
/// </summary>
public enum ScreenUnLockOperationType
{
Remember = 0, Check = 1
}
初始化ScreenUnLock
public ScreenUnlock()
{
InitializeComponent();
this.Loaded += ScreenUnlock_Loaded;
this.Unloaded += ScreenUnlock_Unloaded;
this.MouseMove += ScreenUnlock_MouseMove; //监听绘制事件
}
private void ScreenUnlock_Loaded(object sender, RoutedEventArgs e)
{
isChecking = false;
rightColor = new SolidColorBrush(Colors.Green);
errorColor = new SolidColorBrush(Colors.Red);
currentPointArray = new List<string>();
currentLineList = new List<Line>();
ellipseList = new List<Ellipse>();
CreatePoint();
}
private void ScreenUnlock_Unloaded(object sender, RoutedEventArgs e)
{
rightColor = null;
errorColor = null;
if (currentPointArray != null)
this.currentPointArray.Clear();
if (currentLineList != null)
this.currentLineList.Clear();
if (ellipseList != null)
ellipseList.Clear();
this.canvasRoot.Children.Clear();
}
创建点
1 /// <summary>
2 /// 创建点
3 /// </summary>
4 private void CreatePoint()
5 {
6 canvasRoot.Children.Clear();
7 int row = 3, column = 3; //三行三列，九宫格
8 double oneColumnWidth = (this.ActualWidth == 0 ? this.Width : this.ActualWidth) / 3; //单列的宽度
9 double oneRowHeight = (this.ActualHeight == 0 ? this.Height : this.ActualHeight) / 3; //单列的高度
10 double leftDistance = (oneColumnWidth - PointSize) / 2; //单列左边距
11 double topDistance = (oneRowHeight - PointSize) / 2; //单列上边距
12 for (var i = 0; i < row; i++)
13 {
14 for (var j = 0; j < column; j++)
15 {
16 Ellipse ellipse = new Ellipse()
17 {
18 Width = PointSize,
19 Height = PointSize,
20 Fill = Color,
21 Tag = string.Format("{0}{1}", i, j)
22 };
23 Canvas.SetLeft(ellipse, j * oneColumnWidth + leftDistance);
24 Canvas.SetTop(ellipse, i * oneRowHeight + topDistance);
25 canvasRoot.Children.Add(ellipse);
26 ellipseList.Add(ellipse);
27 }
28 }
29 }
创建线
1 private Line CreateLine()
2 {
3 Line line = new Line()
4 {
5 Stroke = Color,
6 StrokeThickness = 2
7 };
8 return line;
9 }
点和线都创建都定义好了，可以开始监听绘制事件了
1 private void ScreenUnlock_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
2 {
3 if (isChecking) //如果图形正在检查中，不响应后续处理
4 return;
5 if (e.LeftButton == System.Windows.Input.MouseButtonState.Pressed)
6 {
7 var point = e.GetPosition(this);
8 HitTestResult result = VisualTreeHelper.HitTest(this, point);
9 Ellipse ellipse = result.VisualHit as Ellipse;
10 if (ellipse != null)
11 {
12 if (currentLine == null)
13 {
14 //从头开始绘制
15 currentLine = CreateLine();
16 var ellipseCenterPoint = GetCenterPoint(ellipse);
17 currentLine.X1 = currentLine.X2 = ellipseCenterPoint.X;
18 currentLine.Y1 = currentLine.Y2 = ellipseCenterPoint.Y;
19
20 currentPointArray.Add(ellipse.Tag.ToString());
21 Console.WriteLine(string.Join(",", currentPointArray));
22 currentLineList.Add(currentLine);
23 canvasRoot.Children.Add(currentLine);
24 }
25 else
26 {
27 //遇到下一个点，排除已经经过的点
28 if (currentPointArray.Contains(ellipse.Tag.ToString()))
29 return;
30 OnAfterByPoint(ellipse);
31 }
32 }
33 else if (currentLine != null)
34 {
35 //绘制过程中
36 currentLine.X2 = point.X;
37 currentLine.Y2 = point.Y;
38
39 //判断当前Line是否经过点
40 ellipse = IsOnLine();
41 if (ellipse != null)
42 OnAfterByPoint(ellipse);
43 }
44 }
45 else
46 {
47 if (currentPointArray.Count == 0)
48 return;
49 isChecking = true;
50 if (currentLineList.Count + 1 != currentPointArray.Count)
51 {
52 //最后一条线的终点不在点上
53 //两点一线，点的个数-1等于线的条数
54 currentLineList.Remove(currentLine); //从已记录的线集合中删除最后一条多余的线
55 canvasRoot.Children.Remove(currentLine); //从界面上删除最后一条多余的线
56 currentLine = null;
57 }
58
59 if (Operation == ScreenUnLockOperationType.Check)
60 {
61 Console.WriteLine("playAnimation Check");
62 var result = CheckPoint(); //执行图形检查
//执行完成动画并触发检查事件
63 PlayAnimation(result, () =>
64 {
65 if (OnCheckedPoint != null)
66 {
67 this.Dispatcher.BeginInvoke(OnCheckedPoint, this, new CheckPointArgs() { Result = result }); //触发检查完成事件
68 }
69 });
70
71 }
72 else if (Operation == ScreenUnLockOperationType.Remember)
73 {
74 Console.WriteLine("playAnimation Remember");
75 RememberPoint(); //记忆绘制的坐标
76 var args = new RememberPointArgs() { PointArray = this.PointArray };
//执行完成动画并触发记忆事件
77 PlayAnimation(true, () =>
78 {
79 if (OnRememberPoint != null)
80 {
81 this.Dispatcher.BeginInvoke(OnRememberPoint, this, args); //触发图形记忆事件
82 }
83 });
84 }
85 }
86 }
判断线是否经过了附近的某个点
1 /// <summary>
2 /// 两点计算一线的长度
3 /// </summary>
4 /// <param name="pt1"></param>
5 /// <param name="pt2"></param>
6 /// <returns></returns>
7 private double GetLineLength(double x1, double y1, double x2, double y2)
8 {
9 return Math.Sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); //根据两点计算线段长度公式 √((x1-x2)²x(y1-y2)²)
10 }
11
12 /// <summary>
13 /// 判断线是否经过了某个点
14 /// </summary>
16 /// <param name="ellipse"></param>
17 /// <returns></returns>
18 private Ellipse IsOnLine()
19 {
20 double lineAB = 0; //当前画线的长度
21 double lineCA = 0; //当前点和A点的距离
22 double lineCB = 0; //当前点和B点的距离
23 double dis = 0;
24 double deciation = 1; //允许的偏差距离
25 lineAB = GetLineLength(currentLine.X1, currentLine.Y1, currentLine.X2, currentLine.Y2); //计算当前画线的长度
26
27 foreach (Ellipse ellipse in ellipseList)
28 {
29 if (currentPointArray.Contains(ellipse.Tag.ToString())) //排除已经经过的点
30 continue;
31 var ellipseCenterPoint = GetCenterPoint(ellipse); //取当前点的中心点
32 lineCA = GetLineLength(currentLine.X1, currentLine.Y1, ellipseCenterPoint.X, ellipseCenterPoint.Y); //计算当前点到线A端的长度
33 lineCB = GetLineLength(currentLine.X2, currentLine.Y2, ellipseCenterPoint.X, ellipseCenterPoint.Y); //计算当前点到线B端的长度
34 dis = Math.Abs(lineAB - (lineCA + lineCB)); //线CA的长度+线CB的长度>当前线AB的长度 说明点不在线上
35 if (dis <= deciation) //因为绘制的点具有一个宽度和高度，所以需设定一个允许的偏差范围，让线靠近点就命中之（吸附效果）
36 {
37 return ellipse;
38 }
39 }
40 return null;
41 }
检查点是否正确，按数组顺序逐个匹配之
1 /// <summary>
2 /// 检查坐标点是否正确
3 /// </summary>
4 /// <returns></returns>
5 private bool CheckPoint()
6 {
//PointArray:正确的坐标值数组
//currentPointArray:当前绘制的坐标值数组
7 if (currentPointArray.Count != PointArray.Count)
8 return false;
9 for (var i = 0; i < currentPointArray.Count; i++)
10 {
11 if (currentPointArray[i] != PointArray[i])
12 return false;
13 }
14 return true;
15 }
记录经过点，并创建一条新的线
1 /// <summary>
2 /// 记录经过的点
3 /// </summary>
4 /// <param name="ellipse"></param>
5 private void OnAfterByPoint(Ellipse ellipse)
6 {
7 var ellipseCenterPoint = GetCenterPoint(ellipse);
8 currentLine.X2 = ellipseCenterPoint.X;
9 currentLine.Y2 = ellipseCenterPoint.Y;
10 currentLine = CreateLine();
11 currentLine.X1 = currentLine.X2 = ellipseCenterPoint.X;
12 currentLine.Y1 = currentLine.Y2 = ellipseCenterPoint.Y;
13 currentPointArray.Add(ellipse.Tag.ToString());
14 Console.WriteLine(string.Join(",", currentPointArray));
15 currentLineList.Add(currentLine);
16 canvasRoot.Children.Add(currentLine);
17 }
1 /// <summary>
2 /// 获取原点的中心点坐标
3 /// </summary>
4 /// <param name="ellipse"></param>
5 /// <returns></returns>
6 private Point GetCenterPoint(Ellipse ellipse)
7 {
8 Point p = new Point(Canvas.GetLeft(ellipse) + ellipse.Width / 2, Canvas.GetTop(ellipse) + ellipse.Height / 2);
9 return p;
10 }
11
当绘制完成时，执行完成动画并触发响应模式的事件
1 /// <summary>
2 /// 执行动画
3 /// </summary>
4 /// <param name="result"></param>
5 private void PlayAnimation(bool result, Action callback = null)
6 {
7 Task.Factory.StartNew(() =>
8 {
9 this.Dispatcher.Invoke((Action)delegate
10 {
11 foreach (Line l in currentLineList)
12 l.Stroke = result ? rightColor : errorColor;
13 foreach (Ellipse e in ellipseList)
14 if (currentPointArray.Contains(e.Tag.ToString()))
15 e.Fill = result ? rightColor : errorColor;
16 });
17 Thread.Sleep(1500);
18 this.Dispatcher.Invoke((Action)delegate
19 {
20 foreach (Line l in currentLineList)
21 this.canvasRoot.Children.Remove(l);
22 foreach (Ellipse e in ellipseList)
23 e.Fill = Color;
24 });
25 currentLine = null;
26 this.currentPointArray.Clear();
27 this.currentLineList.Clear();
28 isChecking = false;
29 }).ContinueWith(t =>
30 {
31 try
32 {
33 if (callback != null)
34 callback();
35 }
36 catch (Exception ex)
37 {
38 Console.WriteLine(ex.Message);
39 }
40 finally
41 {
42 t.Dispose();
43 }
44 });
45 }
图形解锁的调用
1 <local:ScreenUnlock Width="500" Height="500"
2 PointArray="{Binding PointArray, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
3 Operation="Check"> <!--或Remember-->
4 <i:Interaction.Triggers>
5 <i:EventTrigger EventName="OnCheckedPoint">
6 <Custom:EventToCommand Command="{Binding OnCheckedPoint}" PassEventArgsToCommand="True"/>
7 </i:EventTrigger>
8 <i:EventTrigger EventName="OnRememberPoint">
9 <Custom:EventToCommand Command="{Binding OnRememberPoint}" PassEventArgsToCommand="True"/>
10 </i:EventTrigger>
11 </i:Interaction.Triggers>
12 </local:ScreenUnlock>