为什么Canvas的Background属性的通用＆QUOT;＆的SolidColorBrush QUOT;而不是实际的颜色？ [英] Why is the Canvas' Background property a generic "SolidColorBrush" instead of an actual color?

问题描述

我要到龙头响应在画布上，并在画布背景值存储在应用程序设置，这样我可以分配价值的AppBar /命令栏。所以我有这个XAML用户控件：

 ＆LT; StackPanel的方向=横向＆GT;
    ＆LT;画布底色=水族WIDTH =20HEIGHT =20VerticalAlignment =中心抽头=CanvasColor_Tapped＆GT;＆LT; /帆布＆GT;
    ＆LT; TextBlock的文本=水族VerticalAlignment =中心抽头=CanvasColor_Tapped＆GT;＆LT; / TextBlock的＆GT;
＆LT; / StackPanel的＆GT;
 

..和处理程序是：

 私人无效CanvasColor_Tapped（对象发件人，TappedRoutedEventArgs treArgs）
{
    如果（发送方是帆布）
    {
        刷色=（（Canvas）的发送者）技术领域;
        串brushColorAsStr = colour.ToString（）;
        IAppSettings的appSettings;
        如果（App.SaveSettingsLocally）
        {
            的appSettings =新AppSettingLocal（）;
        }
        其他
        {
            的appSettings =新AppSettingsRoaming（）;
        }
        appSettings.SaveSetting（VisitsConsts.APP_BAR_COLOR_SETTING，brushColorAsStr）;
    }
}
 

然而brushColorAsStr的价值简直是Windows.UI.XAML.Media.SolidColorBrush（我期待它像品红或Windows.UI.XAML.Media.SolidColorBrush.Magenta）

我怎样才能得到背景的实际值，而不是它的类型？

更新

我不只是如何实现SLaks的回答理解;我试过：

 刷brsh =（（Canvas）的发送者）技术领域;
// VAR颜色=（的SolidColorBrush）brsh。
// VAR颜色=（（的SolidColorBrush）发送方）。颜色;
// VAR颜色=（的SolidColorBrush）（（Canvas）的发送者）。颜色。
 

解决方案

拓展上SLaks回答：

例如：

  VAR帆布=发件人作为画布;
VAR刷= canvas.Background为的SolidColorBrush;
VAR颜色= brush.Color;
 

请注意，这工作，因为你设置一个单一的，纯色的默认值。这就是为什么它是一个的SolidColorBrush 。你可以将其设置为任何类型的刷，线性渐变，纹理或任何你喜欢的。原因很明显，如果你设置什么，但一个单一的颜色实心画笔上​​面的code将无法工作。

I want to respond to a tap on a canvas and store the value of the canvas' background in app settings so that I can assign that value to the AppBar / Command Bar. So I have this XAML in a User Control:

<StackPanel Orientation="Horizontal">
    <Canvas Background="Aqua" Width="20" Height="20" VerticalAlignment="Center" Tapped="CanvasColor_Tapped"></Canvas>
    <TextBlock Text="Aqua" VerticalAlignment="Center" Tapped="CanvasColor_Tapped" ></TextBlock>
</StackPanel>

..and the handler is:

private void CanvasColor_Tapped(object sender, TappedRoutedEventArgs treArgs)
{
    if (sender is Canvas)
    {
        Brush colour = ((Canvas)sender).Background;
        String brushColorAsStr = colour.ToString();
        IAppSettings appSettings;
        if (App.SaveSettingsLocally)
        {
            appSettings = new AppSettingLocal();
        }
        else
        {
            appSettings = new AppSettingsRoaming();
        }
        appSettings.SaveSetting(VisitsConsts.APP_BAR_COLOR_SETTING, brushColorAsStr);
    }
}

Yet the value of brushColorAsStr is simply "Windows.UI.XAML.Media.SolidColorBrush" (I'm expecting it to be something like "Magenta" or "Windows.UI.XAML.Media.SolidColorBrush.Magenta")

How can I get the actual value of the background rather than just its type?

UPDATE

I'm not understanding just how to implement SLaks' answer; I've tried:

Brush brsh = ((Canvas) sender).Background;
//var color = (SolidColorBrush)brsh.
//var color = ((SolidColorBrush) sender).Color;
//var color = (SolidColorBrush).((Canvas)sender).Color;

解决方案

Expanding on SLaks answer:

Example:

var canvas = sender as Canvas;
var brush = canvas.Background as SolidColorBrush;
var color = brush.Color;

Please note that this works because you set the default of a single, solid color. That's why it's a SolidColorBrush. You can set it to any kind of brush, linear gradient, textures or whatever you like. For obvious reasons, the code above will not work if you set anything but a single color solid brush.

这篇关于为什么Canvas的Background属性的通用＆QUOT;＆的SolidColorBrush QUOT;而不是实际的颜色？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！