做一个滑块使用现有的IValueConverter [英] Make a slider use an existing IValueConverter

问题描述

我有一个滑块实施< A HREF =htt​​p://msdn.microsoft.com/en-us/library/system.windows.controls.slider%28v=vs.110%29.aspx相对=nofollow> System.Windows.Controls的。滑块：

class MySlider : Slider
{
    public MySlider()
    {
        Minimum = 1;
        Maximum = 1000;
    }
}

我用这样的： MySlider滑块=新MySlider（）{宽度= 400，名称=TheSlider};

它运作良好，但它是线性的。
我希望把它的非线性，因为合理的值是像1，2，10，1000（例如）。
所以我定义了一个非线性的<一个href="http://msdn.microsoft.com/en-us/library/system.windows.data.ivalueconverter%28v=vs.110%29.aspx"相对=nofollow>的IValueConverter 是这样的：

It works well, but it is linear.
I want to make it non-linear because sensible values are like 1, 2, 10, 1000 (for instance).
So I defined a non-linear IValueConverter like this:

public class LogScaleConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return (int)Math.Log((int)value);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return (int)Math.Exp((double)value);
    }
}

问：如何使滑盖使用的转换

推荐答案

更新：给你一个完整的工作code

MainWindow.xaml

<StackPanel>
    <StackPanel.Resources>
        <spikes:LogScaleConverter x:Key="LogScaleConverter"/>
    </StackPanel.Resources>
    <TextBox x:Name="InputNumberTextBox" Width="100" Text="{Binding InputNumber, Mode=TwoWay}"/>
    <Slider Width="1000"
            Minimum="1" 
            Maximum="100"
            Value="{Binding ElementName=InputNumberTextBox,Path=Text, Mode=TwoWay,Converter={StaticResource LogScaleConverter}}"/>
</StackPanel>

LogScaleConverter.cs

public class LogScaleConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        var stringValue = value.ToString();
        if (string.IsNullOrWhiteSpace(stringValue)) return null;

        var intValue = int.Parse(stringValue);
        return Math.Log(intValue);
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return (int)Math.Exp((double)value);
    }
}

注意，现在，当你键入的东西在文本它会改变根据您的公式滑块的价值。你可以把一个破发点上的转换键，看看是否是你真正想要的滑盖的值。

Notice now that when you type something in the textbox it'll change the value of the slider based on your formula. You can put a break point on the Convert and see if that is the value that you really want in the slider.

我不认为有必要创建一个 MySlider 类，因为你只设置了最小和最大属性这已经是可用的实际对象本身。你只应延伸的控制，如果你在创建自定义的东西，如定义自己的依赖属性。

I don't think it is necessary to create a MySlider class since you are only setting the Minimum and Maximum properties which is already available on the actual object itself. You should only be extending a control if you are creating custom stuff like defining your own Dependency Properties.

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