WPF自定義控件（二）——TextBox

　　和之前一樣，先來看看效果：

　　

　　這個TextBox可設置水印,可設置必填和正則表達式驗證。

　　驗證？沒錯，就是驗證！ 就是在輸入完成后，控件一旦失去焦點就會自動驗證！會根據我開放出來的“是否可以為空”屬性進行驗證，一旦為空，則控件變為警告樣式。

　　但這還不是最特別的，為了各種手機號啊，郵箱啊的驗證，我還開放了一個正則表達式的屬性，在這個屬性中填上正則表達式，同上， 一旦失去焦點就會自動驗證輸入的內容能否匹配正則表達式，如果不能匹配，則控件變為警告樣式。

　　之后，代碼還可以通過我開放的另一個屬性來判斷當前輸入框的輸入是否有誤！

　　好了，來看代碼吧：

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:ctrl="clr-namespace:KAN.WPF.XCtrl.Controls">
    <Style TargetType="{x:Type ctrl:XTextBox}">
        <!--StyleFocusVisual在上一篇里說了-->
        <Style.Resources>
            <ResourceDictionary Source="/KAN.WPF.Xctrl;component/Themes/CommonStyle.xaml"/>
        </Style.Resources>
        <Setter Property="FocusVisualStyle" Value="{StaticResource StyleFocusVisual}"/>
        <Setter Property="BorderBrush" Value="Silver"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ctrl:XTextBox}">
                    <Border Name="brdText" Background="{TemplateBinding Background}"  BorderThickness="{TemplateBinding BorderThickness}"
                          BorderBrush="{TemplateBinding BorderBrush}"  SnapsToDevicePixels="true" Padding="2">
                        <Grid>
                            <ScrollViewer x:Name="PART_ContentHost" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                            <StackPanel Orientation="Horizontal" Visibility="Collapsed" Name="stpWatermark">
                                <TextBlock HorizontalAlignment="Left" VerticalAlignment="Center" 
                                           FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}"
                                           Foreground="{Binding XWmkForeground, RelativeSource={RelativeSource TemplatedParent}}" 
                                           Text="{Binding XWmkText, RelativeSource={RelativeSource TemplatedParent}}" Cursor="IBeam" />
                            </StackPanel>
                            <ContentPresenter></ContentPresenter>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <!--當失去焦點並且沒有輸入任何內容時-->
                        <MultiTrigger>
                            <MultiTrigger.Conditions>
                                <Condition Property="Text" Value=""/>
                                <Condition Property="IsFocused" Value="False"/>
                            </MultiTrigger.Conditions>
                            <MultiTrigger.Setters>
                                <Setter Property="Visibility" TargetName="stpWatermark" Value="Visible"/>
                            </MultiTrigger.Setters>
                        </MultiTrigger>
                        <!--當驗證失敗時-->
                        <Trigger Property="XIsError" Value="true">
                            <Setter TargetName="brdText" Property="BorderBrush" Value="Red" />
                            <Setter TargetName="brdText" Property="Background" Value="Beige" />
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

　　再來看看CS:

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Input;
using System.Text.RegularExpressions;

namespace KAN.WPF.XCtrl.Controls
{
    /// <summary>
    /// 擴展輸入框：可設置水印,可設置必填,可設置正則表達式驗證
    /// </summary>
    public class XTextBox:TextBox
    {
        #region 依賴屬性
        public static readonly DependencyProperty XWmkTextProperty;//水印文字
        public static readonly DependencyProperty XWmkForegroundProperty;//水印着色
        public static readonly DependencyProperty XIsErrorProperty;//是否字段有誤
        public static readonly DependencyProperty XAllowNullProperty;//是否允許為空
        public static readonly DependencyProperty XRegExpProperty;//正則表達式
        #endregion

        #region 內部方法
        /// <summary>
        /// 注冊事件
        /// </summary>
        public XTextBox()
        {
            this.LostFocus += new RoutedEventHandler(XTextBox_LostFocus);
            this.GotFocus += new RoutedEventHandler(XTextBox_GotFocus);
            this.PreviewMouseDown += new MouseButtonEventHandler(XTextBox_PreviewMouseDown);
        }

        /// <summary>
        /// 靜態構造函數
        /// </summary>
        static XTextBox()
        {
            //注冊依賴屬性
            XTextBox.XWmkTextProperty = DependencyProperty.Register("XWmkText", typeof(String), typeof(XTextBox), new PropertyMetadata(null));
            XTextBox.XAllowNullProperty = DependencyProperty.Register("XAllowNull", typeof(bool), typeof(XTextBox), new PropertyMetadata(true));
            XTextBox.XIsErrorProperty = DependencyProperty.Register("XIsError", typeof(bool), typeof(XTextBox), new PropertyMetadata(false));
            XTextBox.XRegExpProperty = DependencyProperty.Register("XRegExp", typeof(string), typeof(XTextBox), new PropertyMetadata(""));
            XTextBox.XWmkForegroundProperty = DependencyProperty.Register("XWmkForeground", typeof(Brush), 
                typeof(XTextBox), new PropertyMetadata(Brushes.Silver));
            FrameworkElement.DefaultStyleKeyProperty.OverrideMetadata(typeof(XTextBox), new FrameworkPropertyMetadata(typeof(XTextBox)));
        }

        /// <summary>
        /// 失去焦點時檢查輸入
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void XTextBox_LostFocus(object sender, RoutedEventArgs e)
        {
            this.XIsError = false;
            if (XAllowNull == false && this.Text.Trim() == "")
            {
                this.XIsError = true;
            }
            if (Regex.IsMatch(this.Text.Trim(), XRegExp) == false)
            {
                this.XIsError = true;
            }
        }

        /// <summary>
        /// 獲得焦點時選中文字
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void XTextBox_GotFocus(object sender, RoutedEventArgs e)
        {
            this.SelectAll();
        }

        /// <summary>
        /// 鼠標點擊時選中文字
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void XTextBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            if (this.IsFocused == false)
            {
                TextBox textBox = e.Source as TextBox;
                textBox.Focus();
                e.Handled = true;
            }
        }
        #endregion

        #region 公布屬性
        /// <summary>
        /// 公布屬性XWmkText（水印文字）
        /// </summary>
        public String XWmkText
        {
            get
            {
                return base.GetValue(XTextBox.XWmkTextProperty) as String;
            }
            set
            {
                base.SetValue(XTextBox.XWmkTextProperty, value);
            }
        }

        /// <summary>
        /// 公布屬性XWmkForeground（水印着色）
        /// </summary>
        public Brush XWmkForeground
        {
            get
            {
                return base.GetValue(XTextBox.XWmkForegroundProperty) as Brush;
            }
            set
            {
                base.SetValue(XTextBox.XWmkForegroundProperty, value);
            }
        }

        /// <summary>
        /// 公布屬性XIsError（是否字段有誤）
        /// </summary>
        public bool XIsError
        {
            get
            {
                return (bool)base.GetValue(XTextBox.XIsErrorProperty);
            }
            set
            {
                base.SetValue(XTextBox.XIsErrorProperty, value);
            }
        }

        /// <summary>
        /// 公布屬性XAllowNull（是否允許為空）
        /// </summary>
        public bool XAllowNull
        {
            get
            {
                return (bool)base.GetValue(XTextBox.XAllowNullProperty);
            }
            set
            {
                base.SetValue(XTextBox.XAllowNullProperty, value);
            }
        }

        /// <summary>
        /// 公布屬性XRegExp（正則表達式）
        /// </summary>
        public string XRegExp
        {
            get
            {
                return base.GetValue(XTextBox.XRegExpProperty) as string;
            }
            set
            {
                base.SetValue(XTextBox.XRegExpProperty, value);
            }
        }
        #endregion
    }
}

　　怎么樣？還算不錯吧！我覺得這個控件的用處算是最大的了！用上這個和上一篇的Button基本可以完成很多WPF項目了！

　　不過~好像還少了個主窗體！沒錯！下一篇就來說說怎么自定義主窗體！

　　有疑問的多留言喲！