WPF图形解锁控件ScreenUnLock使用详解

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

/// <summary>
/// 验证正确的颜色
/// </summary>
private SolidColorBrush rightColor;
/// <summary>
/// 验证失败的颜色
/// </summary>
private SolidColorBrush errorColor;
/// <summary>
/// 图案是否在检查中
/// </summary>
private bool isChecking;
public static readonly DependencyProperty PointArrayProperty = DependencyProperty.Register("PointArray", typeof(IList<string>), typeof(ScreenUnlock));
/// <summary>
/// 记忆的坐标点
/// </summary>
public IList<string> PointArray
{
get { return GetValue(PointArrayProperty) as IList<string>; }
set { SetValue(PointArrayProperty, value); }
}
/// <summary>
/// 当前坐标点集合
/// </summary>
private IList<string> currentPointArray;
/// <summary>
/// 当前线集合
/// </summary>
private IList<Line> currentLineList;
/// <summary>
/// 点集合
/// </summary>
private IList<Ellipse> ellipseList;
/// <summary>
/// 当前正在绘制的线
/// </summary>
private Line currentLine;
public static readonly DependencyProperty OperationPorperty = DependencyProperty.Register("Operation", typeof(ScreenUnLockOperationType), typeof(ScreenUnlock), new FrameworkPropertyMetadata(ScreenUnLockOperationType.Remember));
/// <summary>
/// 操作类型
/// </summary>
public ScreenUnLockOperationType Operation
{
get { return (ScreenUnLockOperationType)GetValue(OperationPorperty); }
set { SetValue(OperationPorperty, value); }
}
public static readonly DependencyProperty PointSizeProperty = DependencyProperty.Register("PointSize", typeof(double), typeof(ScreenUnlock), new FrameworkPropertyMetadata(15.0));
/// <summary>
/// 坐标点大小
/// </summary>
public double PointSize
{
get { return Convert.ToDouble(GetValue(PointSizeProperty)); }
set { SetValue(PointSizeProperty, value); }
}
public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(SolidColorBrush), typeof(ScreenUnlock), new FrameworkPropertyMetadata(new SolidColorBrush(Colors.White), new PropertyChangedCallback((s, e) =>
{
(s as ScreenUnlock).Refresh();
})));
/// <summary>
/// 坐标点及线条颜色
/// </summary>
public SolidColorBrush Color
{
get { return GetValue(ColorProperty) as SolidColorBrush; }
set { SetValue(ColorProperty, value); }
}
　　　　/// <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

/// <summary>
/// 创建点
/// </summary>
private void CreatePoint()
{
canvasRoot.Children.Clear();
int row = 3, column = 3; //三行三列，九宫格
double oneColumnWidth = (this.ActualWidth == 0 ? this.Width : this.ActualWidth) / 3; //单列的宽度
double oneRowHeight = (this.ActualHeight == 0 ? this.Height : this.ActualHeight) / 3; //单列的高度
double leftDistance = (oneColumnWidth - PointSize) / 2; //单列左边距
double topDistance = (oneRowHeight - PointSize) / 2; //单列上边距
for (var i = 0; i < row; i++)
{
for (var j = 0; j < column; j++)
{
Ellipse ellipse = new Ellipse()
{
Width = PointSize,
Height = PointSize,
Fill = Color,
Tag = string.Format("{0}{1}", i, j)
};
Canvas.SetLeft(ellipse, j * oneColumnWidth + leftDistance);
Canvas.SetTop(ellipse, i * oneRowHeight + topDistance);
canvasRoot.Children.Add(ellipse);
ellipseList.Add(ellipse);
}
}
}

创建线

private Line CreateLine()
{
Line line = new Line()
{
Stroke = Color,
StrokeThickness = 2
};
return line;
}

点和线都创建都定义好了，可以开始监听绘制事件了

private void ScreenUnlock_MouseMove(object sender, System.Windows.Input.MouseEventArgs e)
{
if (isChecking) //如果图形正在检查中，不响应后续处理
return;
if (e.LeftButton == System.Windows.Input.MouseButtonState.Pressed)
{
var point = e.GetPosition(this);
HitTestResult result = VisualTreeHelper.HitTest(this, point);
Ellipse ellipse = result.VisualHit as Ellipse;
if (ellipse != null)
{
if (currentLine == null)
{
//从头开始绘制
currentLine = CreateLine();
var ellipseCenterPoint = GetCenterPoint(ellipse);
currentLine.X1 = currentLine.X2 = ellipseCenterPoint.X;
currentLine.Y1 = currentLine.Y2 = ellipseCenterPoint.Y;
currentPointArray.Add(ellipse.Tag.ToString());
Console.WriteLine(string.Join(",", currentPointArray));
currentLineList.Add(currentLine);
canvasRoot.Children.Add(currentLine);
}
else
{
//遇到下一个点，排除已经经过的点
if (currentPointArray.Contains(ellipse.Tag.ToString()))
return;
OnAfterByPoint(ellipse);
}
}
else if (currentLine != null)
{
//绘制过程中
currentLine.X2 = point.X;
currentLine.Y2 = point.Y;
//判断当前Line是否经过点
ellipse = IsOnLine();
if (ellipse != null)
OnAfterByPoint(ellipse);
}
}
else
{
if (currentPointArray.Count == 0)
return;
isChecking = true;
if (currentLineList.Count + 1 != currentPointArray.Count)
{
//最后一条线的终点不在点上
//两点一线，点的个数-1等于线的条数
currentLineList.Remove(currentLine); //从已记录的线集合中删除最后一条多余的线
canvasRoot.Children.Remove(currentLine); //从界面上删除最后一条多余的线
currentLine = null;
}
if (Operation == ScreenUnLockOperationType.Check)
{
Console.WriteLine("playAnimation Check");
var result = CheckPoint(); //执行图形检查
　　　　　　　　　　　　　 //执行完成动画并触发检查事件
PlayAnimation(result, () =>
{
if (OnCheckedPoint != null)
{
this.Dispatcher.BeginInvoke(OnCheckedPoint, this, new CheckPointArgs() { Result = result }); //触发检查完成事件
}
});
}
else if (Operation == ScreenUnLockOperationType.Remember)
{
Console.WriteLine("playAnimation Remember");
RememberPoint(); //记忆绘制的坐标
var args = new RememberPointArgs() { PointArray = this.PointArray };
　　　　　　　　　　　　　//执行完成动画并触发记忆事件
PlayAnimation(true, () =>
{
if (OnRememberPoint != null)
{
this.Dispatcher.BeginInvoke(OnRememberPoint, this, args); //触发图形记忆事件
}
});
}
}
}

判断线是否经过了附近的某个点

/// <summary>
/// 两点计算一线的长度
/// </summary>
/// <param name="pt1"></param>
/// <param name="pt2"></param>
/// <returns></returns>
private double GetLineLength(double x1, double y1, double x2, double y2)
{
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)
}
/// <summary>
/// 判断线是否经过了某个点
/// </summary>
/// <param name="ellipse"></param>
/// <returns></returns>
private Ellipse IsOnLine()
{
double lineAB = 0; //当前画线的长度
double lineCA = 0; //当前点和A点的距离
double lineCB = 0; //当前点和B点的距离
double dis = 0;
double deciation = 1; //允许的偏差距离
lineAB = GetLineLength(currentLine.X1, currentLine.Y1, currentLine.X2, currentLine.Y2); //计算当前画线的长度
foreach (Ellipse ellipse in ellipseList)
{
if (currentPointArray.Contains(ellipse.Tag.ToString())) //排除已经经过的点
continue;
var ellipseCenterPoint = GetCenterPoint(ellipse); //取当前点的中心点
lineCA = GetLineLength(currentLine.X1, currentLine.Y1, ellipseCenterPoint.X, ellipseCenterPoint.Y); //计算当前点到线A端的长度
lineCB = GetLineLength(currentLine.X2, currentLine.Y2, ellipseCenterPoint.X, ellipseCenterPoint.Y); //计算当前点到线B端的长度
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
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）
{
return ellipse;
}
}
return null;
}

检查点是否正确，按数组顺序逐个匹配之

/// <summary>
/// 检查坐标点是否正确
/// </summary>
/// <returns></returns>
private bool CheckPoint()
{
　　　　　　　　　//PointArray:正确的坐标值数组
　　　　　　　 //currentPointArray:当前绘制的坐标值数组
if (currentPointArray.Count != PointArray.Count)
return false;
for (var i = 0; i < currentPointArray.Count; i++)
{
if (currentPointArray[i] != PointArray[i])
return false;
}
return true;
}

记录经过点，并创建一条新的线

/// <summary>
/// 记录经过的点
/// </summary>
/// <param name="ellipse"></param>
private void OnAfterByPoint(Ellipse ellipse)
{
var ellipseCenterPoint = GetCenterPoint(ellipse);
currentLine.X2 = ellipseCenterPoint.X;
currentLine.Y2 = ellipseCenterPoint.Y;
currentLine = CreateLine();
currentLine.X1 = currentLine.X2 = ellipseCenterPoint.X;
currentLine.Y1 = currentLine.Y2 = ellipseCenterPoint.Y;
currentPointArray.Add(ellipse.Tag.ToString());
Console.WriteLine(string.Join(",", currentPointArray));
currentLineList.Add(currentLine);
canvasRoot.Children.Add(currentLine);
}

/// <summary>
/// 获取原点的中心点坐标
/// </summary>
/// <param name="ellipse"></param>
/// <returns></returns>
private Point GetCenterPoint(Ellipse ellipse)
{
Point p = new Point(Canvas.GetLeft(ellipse) + ellipse.Width / 2, Canvas.GetTop(ellipse) + ellipse.Height / 2);
return p;
}

当绘制完成时，执行完成动画并触发响应模式的事件

/// <summary>
/// 执行动画
/// </summary>
/// <param name="result"></param>
private void PlayAnimation(bool result, Action callback = null)
{
Task.Factory.StartNew(() =>
{
this.Dispatcher.Invoke((Action)delegate
{
foreach (Line l in currentLineList)
l.Stroke = result ? rightColor : errorColor;
foreach (Ellipse e in ellipseList)
if (currentPointArray.Contains(e.Tag.ToString()))
e.Fill = result ? rightColor : errorColor;
});
Thread.Sleep(1500);
this.Dispatcher.Invoke((Action)delegate
{
foreach (Line l in currentLineList)
this.canvasRoot.Children.Remove(l);
foreach (Ellipse e in ellipseList)
e.Fill = Color;
});
currentLine = null;
this.currentPointArray.Clear();
this.currentLineList.Clear();
isChecking = false;
}).ContinueWith(t =>
{
try
{
if (callback != null)
callback();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
t.Dispose();
}
});
}

图形解锁的调用

<local:ScreenUnlock Width="500" Height="500"
PointArray="{Binding PointArray, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
Operation="Check"> <!--或Remember-->
<i:Interaction.Triggers>
<i:EventTrigger EventName="OnCheckedPoint">
<Custom:EventToCommand Command="{Binding OnCheckedPoint}" PassEventArgsToCommand="True"/>
</i:EventTrigger>
<i:EventTrigger EventName="OnRememberPoint">
<Custom:EventToCommand Command="{Binding OnRememberPoint}" PassEventArgsToCommand="True"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</local:ScreenUnlock>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

您可能感兴趣的文章:

• C# WPF ListView控件的实例详解
• WPF实现带全选复选框的列表控件
• WPF实现ScrollViewer滚动到指定控件处
• WPF中在摄像头视频上叠加控件的解决方案
• WPF中引入WindowsForms控件的方法
• WPF的ListView控件自定义布局用法实例
• 在WPF中动态加载XAML中的控件实例代码
• 超炫酷的WPF实现Loading控件效果
• WPF中不规则窗体与WindowsFormsHost控件兼容问题的解决方法
• WPF自定义选择年月控件详解