使用C#編寫(xiě)兩個(gè)漂亮?xí)r鐘的示例代碼

更新時(shí)間：2023年07月02日 10:14:25 作者：林曉lx

這篇文章主要為大家分享了兩個(gè)使用C#編寫(xiě)的兩個(gè)漂亮?xí)r鐘的示例代碼，文中的示例代碼講解詳細(xì)，具有一定的參考價(jià)值，感興趣的可以了解一下

時(shí)鐘1

繪制鋸齒表盤(pán)

鋸齒表盤(pán)是正玄波曲線閉合成一個(gè)圓形。

創(chuàng)建Clock1，打開(kāi)Xaml文件

在頁(yè)面布局中創(chuàng)建一個(gè)Path對(duì)象，設(shè)置Stroke和Fill屬性。

<Path Grid.Row="0"
        Grid.Column="1"
        Stroke="white"
        Fill="#FFEED9"
        IsVisible="true"
        x:Name="ModulatedPath">
    <Path.Data>
        <PathGeometry>
            <PathGeometry.Figures>
                <PathFigureCollection>
                    <PathFigure IsClosed="True" x:Name="MainPathFigure">
                        <PathFigure.Segments>
                            <PathSegmentCollection x:Name="MainPathSegmentCollection">
                            </PathSegmentCollection>
                        </PathFigure.Segments>
                    </PathFigure>
                </PathFigureCollection>
            </PathGeometry.Figures>
        </PathGeometry>
    </Path.Data>
</Path>

在codebehind中，訂閱SizeChanged事件，當(dāng)控件大小發(fā)生變化時(shí)，重新繪制表盤(pán)。

public Clock1()
{
    InitializeComponent();
    this.SizeChanged+=ContentView_SizeChanged;
}

正弦曲線繪制原理

單位圓中的正弦函數(shù)在平面直角坐標(biāo)系中可以映射為一個(gè)波形曲線，下圖所示在0-2π范圍中y=sin(x)的圖像。

其中最低點(diǎn)和最高點(diǎn)決定了波形的振幅，他們與平衡點(diǎn)的距離即單位圓的半徑

設(shè)置變量 r為平衡點(diǎn)，r2為最高點(diǎn)，r3為最低點(diǎn)。

centerX和centerY為圓心坐標(biāo)。

segemts為繪制的線段數(shù)，越大鋸齒越密集。

private void ContentView_SizeChanged(object sender, EventArgs e)
{
    var length = (float)Math.Min(this.Width, this.Height) * 0.95;
    var centerX = (float)this.Width / 2;
    var centerY = (float)this.Height / 2;
    var points = new List<Point>();
    var r = length / 2;
    var r2 = r * 1.1;
    var r3 = r * 0.9;
    var index = 0;
    var segments = 40;
}

首先計(jì)算各平衡點(diǎn)在圓周上的離散分布坐標(biāo)（x,y）

根據(jù)index的奇偶性，給與當(dāng)前點(diǎn)最高點(diǎn)或最低點(diǎn)的半徑。

根據(jù)各分配的半徑計(jì)算調(diào)整后的離散點(diǎn)坐標(biāo)

代碼如下：

...
for (var i = 0; i < segments; i += 2)
{
    var x = r * Math.Cos(i * 2 * Math.PI / segments) + centerX;
    var y = r * Math.Sin(i * 2 * Math.PI / segments) + centerY;
    points.Add(new Point((float)x, (float)y));
    var currentR = index++ % 2 == 0 ? r2 : r3;
    x = currentR * Math.Cos((i + 1) * 2 * Math.PI / segments) + centerX;
    y = currentR * Math.Sin((i + 1) * 2 * Math.PI / segments) + centerY;
    points.Add(new Point((float)x, (float)y));
}

如此，我們得到一個(gè)閉合的鋸齒圓形表盤(pán)

繪制指針

在表盤(pán)上繪制時(shí)鐘指針，需要計(jì)算時(shí)針、分針、秒針的角度，然后根據(jù)角度旋轉(zhuǎn)畫(huà)布，繪制指針。

秒針每秒鐘轉(zhuǎn)動(dòng)6度，

分針每分鐘轉(zhuǎn)動(dòng)6度，并疊加每秒0.1度。

時(shí)針每小時(shí)轉(zhuǎn)動(dòng)30度。并疊加每分鐘0.5度。

其中時(shí)針和分針由寬度為15的實(shí)心填充圓角線條構(gòu)成

DateTime dateTime = DateTime.Now;
// Hour hand
strokePaint.Color = SKColor.Parse("#5E4000");
strokePaint.StrokeWidth = 15;
canvas.Save();
canvas.RotateDegrees(30 * dateTime.Hour + dateTime.Minute / 2f);
canvas.DrawLine(0, 0, 0, -r*(float)0.4, strokePaint);
canvas.Restore();
// Minute hand
strokePaint.Color = SKColor.Parse("#9C6D00");
canvas.Save();
canvas.RotateDegrees(6 * dateTime.Minute + dateTime.Second / 10f);
canvas.DrawLine(0, 0, 0, -r*(float)0.8, strokePaint);
canvas.Restore();
// Second hand
strokePaint.Color = SKColor.Parse("#657E3F");
canvas.Save();
canvas.RotateDegrees(6 * dateTime.Second);
strokePaint.StrokeWidth *=(float)0.5;
strokePaint.Style=SKPaintStyle.Fill;
canvas.DrawCircle(0, -r*(float)0.8, strokePaint.StrokeWidth, strokePaint);
canvas.Restore();

指針效果如下：

其中秒針需要繪制一個(gè)點(diǎn)，在其以圓心為中心的對(duì)側(cè)繪制一個(gè)帶有日期的文本

繪制沿路徑文本

首先繪制文本路徑，它是一個(gè)圓弧，在初始狀態(tài)圓弧的角度為20度，圓弧的起始角度為70度，終止角度為110度。

var pathAngle = 20;
var startAngle = 90-pathAngle;
var sweepAngle = pathAngle*2;
var rect = new SKRect(-r*(float)0.8, -r*(float)0.8, r*(float)0.8, r*(float)0.8);

使用SkiaSharp的DrawTextOnPath方法繪制沿路徑的文本，詳情請(qǐng)查看官方文檔

using (SKPath path = new SKPath())
{
    path.AddArc(rect, startAngle, sweepAngle);
    canvas.DrawTextOnPath(dateStr, path, new SKPoint(), strokePaint);
}

指針效果如下：

時(shí)鐘1的完整代碼如下：

void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
    SKImageInfo info = args.Info;
    SKSurface surface = args.Surface;
    SKCanvas canvas = surface.Canvas;
    canvas.Clear();
    using (SKPaint strokePaint = new SKPaint())
    using (SKPaint fillPaint = new SKPaint())
    {
        strokePaint.Style = SKPaintStyle.Stroke;
        strokePaint.StrokeCap = SKStrokeCap.Round;
        fillPaint.Style = SKPaintStyle.Fill;
        fillPaint.Color = SKColors.Transparent;
        // Transform for 100-radius circle centered at origin
        var r = 100f;
        canvas.Translate(info.Width / 2f, info.Height / 2f);
        canvas.Scale(Math.Min(info.Width / 200f, info.Height / 200f));
        DateTime dateTime = DateTime.Now;
        // Hour hand
        strokePaint.Color = SKColor.Parse("#5E4000");
        strokePaint.StrokeWidth = 15;
        canvas.Save();
        canvas.RotateDegrees(30 * dateTime.Hour + dateTime.Minute / 2f);
        canvas.DrawLine(0, 0, 0, -r*(float)0.4, strokePaint);
        canvas.Restore();
        // Minute hand
        strokePaint.Color = SKColor.Parse("#9C6D00");
        canvas.Save();
        canvas.RotateDegrees(6 * dateTime.Minute + dateTime.Second / 10f);
        canvas.DrawLine(0, 0, 0, -r*(float)0.62, strokePaint);
        canvas.Restore();
        // Second hand
        strokePaint.Color = SKColor.Parse("#657E3F");
        canvas.Save();
        canvas.RotateDegrees(6 * dateTime.Second);
        strokePaint.StrokeWidth *=(float)0.5;
        strokePaint.Style=SKPaintStyle.Fill;
        canvas.DrawCircle(0, -r*(float)0.8, strokePaint.StrokeWidth, strokePaint);
        strokePaint.Color = SKColors.Black;
        strokePaint.StrokeWidth = 1;
        var dateStr = dateTime.ToString("M");
        var pathAngle = 20;
        var startAngle = 90-pathAngle;
        var sweepAngle = pathAngle*2;
        var rect = new SKRect(-r*(float)0.8, -r*(float)0.8, r*(float)0.8, r*(float)0.8);
        using (SKPath path = new SKPath())
        {
            path.AddArc(rect, startAngle, sweepAngle);
            //canvas.DrawPath(path, strokePaint);
            canvas.DrawTextOnPath(dateStr, path, new SKPoint(), strokePaint);
        }
        canvas.Restore();
    }
}

配置一個(gè)定時(shí)器，每秒刷新各指針位置

IDispatcherTimer _timer;
public Clock1()
{
    ...
    this.SizeChanged+=ContentView_SizeChanged;
    _timer=  Dispatcher.CreateTimer();
    _timer.Interval=TimeSpan.FromSeconds(1);
    _timer.Tick+=_timer_Tick;
    _timer.Start();
}
private void _timer_Tick(object sender, EventArgs e)
{
    this.canvasView?.InvalidateSurface();
}

時(shí)鐘1 效果如下：

時(shí)鐘2

將URWGeometricBlack字體文件放到Fonts目錄下

在MauiProgram.cs中注冊(cè)字體

.ConfigureFonts(fonts =>
{
    ...
    fonts.AddFont("URWGeometricBlack.otf", "URWGeometricBlack");
});

繪制表盤(pán)

時(shí)鐘2的表盤(pán)相對(duì)簡(jiǎn)單，是一個(gè)簡(jiǎn)單的圓配簡(jiǎn)潔抽象的數(shù)字刻度組成

創(chuàng)建Clock2，打開(kāi)Xaml文件，代碼如下：

<Grid>
    <Ellipse Grid.Row="0"
                Grid.Column="1"
                Stroke="white"
                Fill="#FFEED9"
                IsVisible="true"
                HeightRequest="200"
                WidthRequest="200"
                x:Name="ModulatedPath">
    </Ellipse>
    <Grid TranslationY="-15">
        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <Label   Grid.Row="0"
                    Grid.ColumnSpan="2"
                    Text="12"
                    Style="{StaticResource ClockPlateNumberLabelStyle}"></Label>
        <Label   Grid.RowSpan="2"
                    Grid.Column="1"
                    Text="3"
                    Style="{StaticResource ClockPlateNumberLabelStyle}"></Label>
        <Label   Grid.Row="1"
                    Grid.ColumnSpan="2"
                    Text="6"
                    Style="{StaticResource ClockPlateNumberLabelStyle}"></Label>
        <Label   Grid.RowSpan="2"
                    Grid.Column="0"
                    Text="9"
                    Style="{StaticResource ClockPlateNumberLabelStyle}"></Label>
    </Grid>
    <forms:SKCanvasView x:Name="canvasView"
                        PaintSurface="OnCanvasViewPaintSurface" />
    <Label FontSize="28"
            HorizontalOptions="Center"
            VerticalOptions="Center"
            x:Name="labelView"></Label>
</Grid>

同樣我們需要放置SKCanvasView對(duì)象用于繪制指針

其中ClockPlateNumberLabelStyle定義如下：

<Style TargetType="Label"
        x:Key="ClockPlateNumberLabelStyle">
    <Setter Property="HorizontalTextAlignment"
            Value="Center"></Setter>
    <Setter Property="VerticalTextAlignment"
            Value="Center"></Setter>
    <Setter Property="VerticalOptions"
            Value="Center"></Setter>
    <Setter Property="FontAttributes"
            Value="Bold"></Setter>
    <Setter Property="FontSize"
            Value="120"></Setter>
    <Setter Property="TextColor"
            Value="#F9BC49"></Setter>
    <Setter Property="FontFamily"
            Value="URWGeometricBlack"></Setter>
</Style>

效果如下：

繪制指針

時(shí)鐘2的指針繪制原理與時(shí)鐘1類似，此處將不贅述，完整代碼如下：

void OnCanvasViewPaintSurface(object sender, SKPaintSurfaceEventArgs args)
{
    SKImageInfo info = args.Info;
    SKSurface surface = args.Surface;
    SKCanvas canvas = surface.Canvas;
    canvas.Clear();
    using (SKPaint strokePaint = new SKPaint())
    using (SKPaint fillPaint = new SKPaint())
    {
        strokePaint.Style = SKPaintStyle.Stroke;
        strokePaint.StrokeCap = SKStrokeCap.Round;
        fillPaint.Style = SKPaintStyle.Fill;
        fillPaint.Color = SKColors.Transparent;
        // Transform for 100-radius circle centered at origin
        var r = 100f;
        canvas.Translate(info.Width / 2f, info.Height / 2f);
        canvas.Scale(Math.Min(info.Width / 200f, info.Height / 200f));
        DateTime dateTime = DateTime.Now;
        // Hour hand
        strokePaint.Color = SKColor.Parse("#5E4000");
        strokePaint.StrokeWidth = 15;
        canvas.Save();
        canvas.RotateDegrees(30 * dateTime.Hour + dateTime.Minute / 2f);
        canvas.DrawLine(0, 0, 0, -r*(float)0.4, strokePaint);
        canvas.Restore();
        // Minute hand
        strokePaint.Color = SKColor.Parse("#9C6D00");
        strokePaint.StrokeWidth = 5;
        canvas.Save();
        canvas.RotateDegrees(6 * dateTime.Minute + dateTime.Second / 10f);
        canvas.DrawLine(0, 0, 0, -r*(float)0.8, strokePaint);
        canvas.Restore();
        // Second hand
        strokePaint.Color = SKColor.Parse("#657E3F");
        strokePaint.StrokeWidth = 2;
        canvas.Save();
        canvas.RotateDegrees(6 * dateTime.Second);
        canvas.DrawLine(0, r*(float)0.1, 0, -r*(float)0.8, strokePaint);
        strokePaint.Style=SKPaintStyle.Fill;
        canvas.DrawCircle(0, 0, 5, strokePaint);
        canvas.Restore();
    }
}

時(shí)鐘2 效果如下