原文:

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/BYH371256/article/details/83652540

本章讲述：使用WPF，实现 带水印的密码输入框实现、带水印的输入框；

自定义控件实现：

样式模板代码

后台实现代码

public class ExTextBox : TextBox        //1.首先创建一个类，继承TextBox    {        //2.指定依赖属性的实例重写基类型的元数据        static ExTextBox()        {            DefaultStyleKeyProperty.OverrideMetadata(typeof(ExTextBox), new FrameworkPropertyMetadata(typeof(ExTextBox)));        }        Image OperateImageE;        Image TipImageE;        public override void OnApplyTemplate()        {            base.OnApplyTemplate();            var bord = VisualTreeHelper.GetChild(this, 0) as Border;            Grid gr = bord.FindName("gdpassword") as Grid;            TipImageE = gr.FindName("TipImage") as Image;            OperateImageE = gr.FindName("OperateImage") as Image;            //TipImageE.PreviewMouseLeftButtonUp +=TipImageE_PreviewMouseLeftButtonUp;            OperateImageE.PreviewMouseLeftButtonUp +=OperateImageE_PreviewMouseLeftButtonUp;        }        private void OperateImageE_PreviewMouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)        {            this.Text = "";        }        //3.定义依赖属性　        public static DependencyProperty WaterRemarkProperty =            DependencyProperty.Register("WaterRemark", typeof(string), typeof(ExTextBox));        /// 
        /// 水印文字        /// 
        public string WaterRemark        {            get { return GetValue(WaterRemarkProperty).ToString(); }            set { SetValue(WaterRemarkProperty, value); }        }        public static DependencyProperty BorderCornerRadiusProperty =            DependencyProperty.Register("BorderCornerRadius", typeof(CornerRadius), typeof(ExTextBox));        /// 
        /// 边框角度        /// 
        public CornerRadius BorderCornerRadius        {            get { return (CornerRadius)GetValue(BorderCornerRadiusProperty); }            set { SetValue(BorderCornerRadiusProperty, value); }        }        public static DependencyProperty IsPasswordBoxProperty =            DependencyProperty.Register("IsPasswordBox", typeof(bool), typeof(ExTextBox), new FrameworkPropertyMetadata(false, new PropertyChangedCallback(OnIsPasswordBoxChnage)));        /// 
        /// 是否为密码框        /// 
        public bool IsPasswordBox        {            get { return (bool)GetValue(IsPasswordBoxProperty); }            set { SetValue(IsPasswordBoxProperty, value); }        }        public static DependencyProperty PasswordCharProperty =            DependencyProperty.Register("PasswordChar", typeof(char), typeof(ExTextBox), new FrameworkPropertyMetadata('●'));        /// 
        /// 替换明文的单个密码字符        /// 
        public char PasswordChar        {            get { return (char)GetValue(PasswordCharProperty); }            set { SetValue(PasswordCharProperty, value); }        }        public static DependencyProperty PasswordStrProperty =            DependencyProperty.Register("PasswordStr", typeof(string), typeof(ExTextBox), new FrameworkPropertyMetadata(string.Empty));        /// 
        /// 密码字符串        /// 
        public string PasswordStr        {            get { return GetValue(PasswordStrProperty).ToString(); }            set { SetValue(PasswordStrProperty, value); }        }        /// 
        /// 图标大小        /// 
        public double ImageSize        {            get { return (double)GetValue(ImageSizeProperty); }            set { SetValue(ImageSizeProperty, value); }        }        public static readonly DependencyProperty ImageSizeProperty =            DependencyProperty.Register("ImageSize", typeof(double), typeof(ExTextBox),            new FrameworkPropertyMetadata(26.0, FrameworkPropertyMetadataOptions.AffectsRender));        public static readonly DependencyProperty TipImageProperty = DependencyProperty.Register(              "TipImage",              typeof(string),              typeof(ExTextBox),              new FrameworkPropertyMetadata("", FrameworkPropertyMetadataOptions.AffectsRender, ImageSourceChanged));        /// 
        ///        /// 
        public string TipImage        {            get { return (string)GetValue(TipImageProperty); }            set { SetValue(TipImageProperty, value); }        }        public static readonly DependencyProperty OperateImageProperty = DependencyProperty.Register(                      "OperateImage",                      typeof(string),                      typeof(ExTextBox),                      new FrameworkPropertyMetadata("", FrameworkPropertyMetadataOptions.AffectsRender, ImageSourceChanged));        /// 
        ///        /// 
        public string OperateImage        {            get { return (string)GetValue(OperateImageProperty); }            set { SetValue(OperateImageProperty, value); }        }        public static readonly DependencyProperty TipImageHideProperty = DependencyProperty.Register(              "TipImageHide",              typeof(Visibility),              typeof(ExTextBox),              new FrameworkPropertyMetadata(Visibility.Collapsed));        /// 
        ///        /// 
 public Visibility TipImageHide { get { return (Visibility)GetValue(TipImageHideProperty); } set { SetValue(TipImageHideProperty, value); } } public static readonly DependencyProperty OperateHideProperty = DependencyProperty.Register( "OperateHide", typeof(Visibility), typeof(ExTextBox), new FrameworkPropertyMetadata(Visibility.Collapsed)); /// 
 /// /// 
 public Visibility OperateHide { get { return (Visibility)GetValue(OperateHideProperty); } set { SetValue(OperateHideProperty, value); } } //依赖属性发生改变时候触发 private static void ImageSourceChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e) { Application.GetResourceStream(new Uri((string)e.NewValue)); if(e.Property.Name == "TipImage") { (sender as ExTextBox).TextBox_Changed(0); } if (e.Property.Name == "OperateImage") { (sender as ExTextBox).TextBox_Changed(1); } } private void TextBox_Changed(int index) { if (index == 0) TipImageHide = Visibility.Visible; else OperateHide = Visibility.Visible; } //4.当设置为密码框时，监听TextChange事件，处理Text的变化，这是密码框的核心功能 private static void OnIsPasswordBoxChnage(DependencyObject sender, DependencyPropertyChangedEventArgs e) { (sender as ExTextBox).SetEvent(); } /// 
 /// 定义TextChange事件 /// 
 private void SetEvent() { if (IsPasswordBox) this.TextChanged += TextBox_TextChanged; else this.TextChanged -= TextBox_TextChanged; } //5.在TextChange事件中，处理Text为密码文，并将原字符记录给PasswordStr予以存储 private void TextBox_TextChanged(object sender, TextChangedEventArgs e) { if (!IsResponseChange) //响应事件标识，替换字符时，不处理后续逻辑 return; //Console.WriteLine(string.Format("------{0}------", e.Changes.Count)); foreach (TextChange c in e.Changes) { //Console.WriteLine(string.Format("addLength:{0} removeLenth:{1} offSet:{2}", c.AddedLength, c.RemovedLength, c.Offset)); PasswordStr = PasswordStr.Remove(c.Offset, c.RemovedLength); //从密码文中根据本次Change对象的索引和长度删除对应个数的字符 PasswordStr = PasswordStr.Insert(c.Offset, Text.Substring(c.Offset, c.AddedLength)); //将Text新增的部分记录给密码文 lastOffset = c.Offset; } //Console.WriteLine(PasswordStr); /*将文本转换为密码字符*/ IsResponseChange = false; //设置响应标识为不响应 this.Text = ConvertToPasswordChar(Text.Length); //将输入的字符替换为密码字符 IsResponseChange = true; //回复响应标识 this.SelectionStart = lastOffset + 1; //设置光标索引 //Console.WriteLine(string.Format("SelectionStar:{0}", this.SelectionStart)); } /// 
 /// 按照指定的长度生成密码字符 /// 
 ///  /// 
                 private string ConvertToPasswordChar(int length) { if (PasswordBuilder != null) PasswordBuilder.Clear(); else PasswordBuilder = new StringBuilder(); for (var i = 0; i < length; i++) PasswordBuilder.Append(PasswordChar); return PasswordBuilder.ToString(); } //6.如果用户设置了记住密码，密码文(PasswordStr)一开始就有值的话，别忘了在Load事件里事先替换一次明文 private void ExTextBox_Loaded(object sender, RoutedEventArgs e) { if (IsPasswordBox) { IsResponseChange = false; this.Text = ConvertToPasswordChar(PasswordStr.Length); IsResponseChange = true; } } private bool IsResponseChange = true; private StringBuilder PasswordBuilder; private int lastOffset = 0; }

调用示例代码

效果图