WPF：找不到自定義驗證規則

Question

所以我嘗試在WPF上設置我的自定義號碼驗證：

public class NumberValidation : ValidationRule {
    private int _min;
    private int _max;

    public NumberValidation() {
    }

    public int Min {
        get { return _min; }
        set { _min = value; }
    }

    public int Max {
        get { return _max; }
        set { _max = value; }
    }

    public override ValidationResult Validate(object value, CultureInfo cultureInfo) {
        int age = 0;

        try {
            if (((string)value).Length > 0)
                age = Int32.Parse((String)value);
        } catch (Exception e) {
            return new ValidationResult(false, "Illegal characters or " + e.Message);
        }

        if ((age < Min) || (age > Max)) {
            return new ValidationResult(false,
              "Please enter an age in the range: " + Min + " - " + Max + ".");
        } else {
            return new ValidationResult(true, null);
        }
    }
}

然后嘗試在XML中實現它：

<Window x:Class="MiningControl.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525" 
        DataContext="{Binding}">
    <Grid>
        <TextBox Height="23" HorizontalAlignment="Right" Margin="0,74,161,0" Name="txb_idleTime" VerticalAlignment="Top" Width="120"
            >
            <TextBox.Text>
                <Binding Path="MinIdleTime" UpdateSourceTrigger="PropertyChanged" >
                    <Binding.ValidationRules>
                        <NumberValidation Min="10" Max="3600" />
                    </Binding.ValidationRules>
                </Binding>
            </TextBox.Text>
        </TextBox>
        <Label Content="Minimum Idle Time (min):" Height="28" HorizontalAlignment="Left" Margin="23,72,0,0" Name="label1" VerticalAlignment="Top" Width="202" HorizontalContentAlignment="Right" />
    </Grid>
</Window>

但是它不起作用，總是說XML命名空間中不存在“ NumberValidation”，我在做什么錯？

Answer 1

您缺少名稱空間導入 。 將以下xmlns:l添加到您的Window聲明中，為您自己更改YourAppNamespace ：

<Window x:Class="MiningControl.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:l="clr-namespace:YourAppNamespace"
    Title="MainWindow" Height="350" Width="525" 
    DataContext="{Binding}">

然后在NumberValidation之前聲明一個命名空間，在本例中為l ：

<l:NumberValidation Min="10" Max="3600" />

請注意，如果NumberValidation駐留在其他程序集中，則需要指定它，例如：

xmlns:l="clr-namespace:VendorControlLibrary;assembly=VendorControlLibrary"

Answer 2

您需要添加對存在NumberValidation的名稱空間的引用。

例如：

<Window x:Class="MiningControl.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:numberValidation="clr-namespace:TheAppsNamespace"
    Title="MainWindow" Height="350" Width="525" 
    DataContext="{Binding}">

然后，您可以像這樣使用它：

<numberValidation:NumberValidation Min="10" Max="3600" />