PDFOffice_Windows_exe/PDF Office/CustomControl/TextBoxEx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace PDF_Office.CustomControl
{
    /// <summary>
    /// 带预文本和圆角的textbox
    /// </summary>
    public class TextBoxEx : TextBox
    {
        static TextBoxEx()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(TextBoxEx), new FrameworkPropertyMetadata(typeof(TextBoxEx)));
        }

        ~TextBoxEx()
        {
            var btn = base.GetTemplateChild("PART_BtnClear") as Button;
            if (btn != null)
            {
                //一定要取消事件挂载，否则可能无法被GC回收
                btn.Click -= Btn_Click;
            }
        }

        public override void OnApplyTemplate()
        {
            //需要配合特定的Style才可用
            var btn = base.GetTemplateChild("PART_BtnClear") as Button;
            if(btn!=null)
            {
                btn.Click += Btn_Click;
            }

            base.OnApplyTemplate();
        }

        private void Btn_Click(object sender, RoutedEventArgs e)
        {
            this.Text = "";
            this.Focus();
        }

        public string PlaceholderText
        {
            get { return (string)GetValue(PlaceholderTextProperty); }
            set { SetValue(PlaceholderTextProperty, value); }
        }

        public static readonly DependencyProperty PlaceholderTextProperty
        = DependencyProperty.Register("PlaceholderText", typeof(string), typeof(TextBoxEx), null);

        public CornerRadius CornerRadius
        {
            get { return (CornerRadius)GetValue(CornerRadiusProperty); }
            set { SetValue(CornerRadiusProperty, value); }
        }

        public static readonly DependencyProperty CornerRadiusProperty =
            DependencyProperty.Register("CornerRadius", typeof(CornerRadius), typeof(TextBoxEx), new PropertyMetadata(new CornerRadius(4)));

        public Brush PlaceholderForeground
        {
            get { return (Brush)GetValue(PlaceholderForegroundProperty); }
            set { SetValue(PlaceholderForegroundProperty, value); }
        }

        public static readonly DependencyProperty PlaceholderForegroundProperty =
          DependencyProperty.Register("PlaceholderForeground", typeof(Brush), typeof(TextBoxEx), new PropertyMetadata(new SolidColorBrush((Color)ColorConverter.ConvertFromString("#94989C"))));

        public Brush MouseOverForeground
        {
            get
            {
                return (Brush)GetValue(MouseOverForegroundProperty);
            }
            set { SetValue(MouseOverForegroundProperty, value); }
        }

        public static readonly DependencyProperty MouseOverForegroundProperty =
     DependencyProperty.Register("MouseOverForeground", typeof(Brush), typeof(TextBoxEx), new PropertyMetadata(new SolidColorBrush(Colors.Transparent)));

    }
}