wpf mvvm 文本输入内容限定指定内容

项目中遇到部分场景需要用到限定的内容，例如输入的是（数字，或英文或字符等）

项目中采用mvvm的设计模式

 <ItemsControl Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Center" Visibility="{Binding VoteType,UpdateSourceTrigger=PropertyChanged,Converter={StaticResource GenericTypeCvt},ConverterParameter='2:Visible|other:Collapsed'}"  Background="Transparent" ItemsSource="{Binding Option.voteTagList}" BorderThickness="0" >
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal" Margin="0,20,0,0" >
                                <StackPanel Orientation="Horizontal" Margin="0,0,60,0" Width="370">
                                    <Label Content="{Binding num}" Foreground="{Binding color}"  FontWeight="Bold" FontSize="30" FontFamily="{StaticResource ElementIcon}" Margin="0,0,10,0"></Label>
                                    <!--<Label Content="{Binding tagWords}" Foreground="#999999" FontWeight="Bold" FontFamily="{StaticResource ElementIcon}"></Label>-->
                                    <!--<Label Content="{Binding tagWords}" Foreground="#999999" FontWeight="Bold" FontSize="30" FontFamily="{StaticResource ElementIcon}"></Label>-->
                                    <TextBlock Text="{Binding tagWords}" Foreground="#999999" FontWeight="Bold" FontSize="34" FontFamily="{StaticResource ElementIcon}" Width="320" TextTrimming="CharacterEllipsis"></TextBlock>
                                   
                                </StackPanel>
                                <TextBox VerticalAlignment="Center" Width ="240" Height=" 40" FontSize="30" FontFamily="{StaticResource ElementIcon}" Text="{Binding tagScore,Mode=TwoWay}"/>
                            </StackPanel>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>

从UI的层面去做输入限定，创建一个文本textbox覆盖该OnPreviewTextInput方法的简单子类型，决定从那限定其输入的内容

public class MemTextBox : TextBox
{
    private static readonly Regex regex = new Regex("^[a-zA-Z]+$");//限定输入英文

    protected override void OnPreviewTextInput(TextCompositionEventArgs e)
    {
        if (!regex.IsMatch(e.Text))
            e.Handled = true;
        base.OnPreviewTextInput(e);
    }
}

在vm中，对输入的内容进行限定，由于v 绑定的是选项的「对象」的一个子项。所以需要对整个对象进行for 循环取值然后对其内容进行判断。后台取值然后对内容进行限定。由于是循环消耗性能，取值进行判断等一系列的操作。

 for (int i = 0; i < Option.voteTagList.Count; i++)
                {
                   
                    Ballot ballot = new Ballot();
                    ballot.createTime = NowTime;
                    ballot.id = Option.id;
                    ballot.tagScore = Option.voteTagList[i].tagScore;
                    var dd = Option.voteTagList[i].tagScore;
                    if (!Regex.IsMatch(dd, @"^([1-9]\d{0,9}|0)([.]?|(\.\d{1,2})?)$"))
                    {
                        ballot.tagScore = dd;
                    }
                    ballot.tagWords = Option.voteTagList[i].tagWords;
                    ballot.username = Global.UserName;
                    ballot.usernameList = null;
                    ballot.voteId = _Voteid;
                    ballot.voteNum = Option.voteTagList.Count;
                    ballots.Add(ballot);
                }

通过文本预览事件与正则区配，定义正则，与输入的内容进行区配，正常下已经处理完成，但存在中文输入法输入时，会有问题

  private void TextBox_PreviewTextInput(object sender, TextCompositionEventArgs e)
        {
            Regex regex = new Regex("[^0-9]+");
            e.Handled = regex.IsMatch(e.Text);
        }