WPF笔记: NumberStringTextbox 并带错误提示

(转载请注明来源:cnblogs coder-fang)

自定义number string textbox 在wpf中,可以在xaml层控制是否为空，长度限制等

1.　　创建textbox父类，使其具有相关依赖属性:

　　

 public class TextboxBase:TextBox
    {
        
        public bool CanEmpty
        {
            get { return (bool)GetValue(CanEmptyProperty); }
            set
            {
                SetValue(CanEmptyProperty, value);
                ValidText();
            }

        }

        public int MaxTextLength
        {
            get { return (int)GetValue(MaxTextLengthProperty); }
            set
            {

                SetValue(MaxTextLengthProperty, value);
            }
        }
        public bool Valid
        {
            get { return (bool)GetValue(ValidProperty); }
            set
            {
                SetValue(ValidProperty, value);
            }
        }
        public string InvalidText
        {
            get { return (string)GetValue(InvalidTextProperty); }
            set
            {
                SetValue(InvalidTextProperty, value);

            }
        }
        public static readonly DependencyProperty MaxTextLengthProperty =
           DependencyProperty.Register("MaxTextLength", typeof(int), typeof(TextboxBase));
        public static readonly DependencyProperty ValidProperty =
           DependencyProperty.Register("Valid", typeof(bool), typeof(TextboxBase));
        public static readonly DependencyProperty InvalidTextProperty =
           DependencyProperty.Register("InvalidText", typeof(string), typeof(TextboxBase));
        public static readonly DependencyProperty CanEmptyProperty =
          DependencyProperty.Register("CanEmpty", typeof(bool), typeof(TextboxBase));
        public delegate bool ValidDelegate(out string Invalidtext);
        public ValidDelegate ValidFunc;

        public TextboxBase()
        {
            this.TextChanged += TextboxBase_TextChanged;
            CanEmpty = false;
            MaxTextLength = Int32.MaxValue;

            ValidFunc = (out string invalidtext) =>
            {
                invalidtext = "";
                return true;
            };
        }

        private void TextboxBase_TextChanged(object sender, TextChangedEventArgs e)
        {
            ValidText();
        }

        public virtual bool ValidText()
        {

            if (!CanEmpty && Text == "" && DataContext != null)
            {
                Valid = false;
                InvalidText = "Can not be empty";
                return false;
            }
            else if (Text.Length > MaxTextLength)
            {
                Valid = false;
                InvalidText = "Max length is " + MaxTextLength;
                return false;
            }
            else
            {
                InvalidText = null;
                Valid = true;
                return true;
            }

        }
    }

2.　　创建Number string类:

 public class NumStrTextbox:TextboxBase
    {
        Regex regex = new Regex(@"^d+$");
        public NumStrTextbox()
        {
            this.PreviewKeyDown += NumStrTextbox_PreviewKeyDown;
            System.Windows.Input.InputMethod.SetIsInputMethodEnabled(this, false);
        }
        public override bool ValidText()
        {
            var ret = base.ValidText();
            if (!ret)
            {
                return false;
            }
            if (!regex.IsMatch(Text))
            {
                InvalidText = "Only numbers is allowed";
                Valid = false;
                ret = false;
            }
            return false;
        }

        private void NumStrTextbox_PreviewKeyDown(object sender, System.Windows.Input.KeyEventArgs e)
        {
            if (((e.Key >= Key.D0 && e.Key <= Key.D9) ||(e.Key >= Key.NumPad0 && e.Key <= Key.NumPad9))
                &&!e.KeyboardDevice.IsKeyDown(Key.LeftShift)&& !e.KeyboardDevice.IsKeyDown(Key.LeftShift)
               )
            {
                
            }
            
            else if (e.Key == Key.Back || e.Key == Key.Delete || (e.Key >= Key.Left && e.Key <= Key.Down) ||
                e.Key == Key.Tab || 
                (e.Key >= Key.End && e.Key <= Key.Home))
            {
            }
            else
            {
                e.Handled = true;
                return;
            }
        }
    }

3.　　创建textbox相关style,使其在异常有红色提示信息

<Style TargetType="UITextbox:TextboxBase" x:Key="WPFUITextboxBaseStyle" >
        <Setter Property="VerticalAlignment" Value="Center"></Setter>
        <Setter Property="VerticalContentAlignment" Value="Center"></Setter>
        <Setter Property="CaretBrush" Value="White"></Setter>
        <Setter Property="MinHeight" Value="25"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type UITextbox:TextboxBase}">
                    <Grid>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="auto" />
                            <RowDefinition/>
                        </Grid.RowDefinitions>
                        <TextBlock Grid.Row="0" Foreground="Salmon" Text="{TemplateBinding InvalidText}" Visibility="{TemplateBinding Valid,Converter={StaticResource TrueCollapseCvt}}"></TextBlock>
                        <Border Grid.Row="1"  x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" SnapsToDevicePixels="true">
                            <ScrollViewer x:Name="PART_ContentHost" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                        </Border>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Style.Triggers>

            <Trigger Property="Valid" Value="false">
                <Setter Property="BorderBrush" Value="Red"></Setter>
            </Trigger>

        </Style.Triggers>

    </Style>

效果图: