Winform界面设计之-TextBox水印提示

最新推荐文章于 2024-01-03 20:05:04 发布

原创最新推荐文章于 2024-01-03 20:05:04 发布 · 1k 阅读

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CC 4.0 BY-SA版权

本文介绍了一种在Windows Forms应用程序中实现带水印提示的文本框的方法。通过创建自定义控件WaterTextBox，并覆盖TextBox的一些属性和事件来实现水印效果。文章提供了完整的源代码示例。

先给出效果图：

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以下为具体代码：

1、新建一个Component Class命名为WaterTextBox

2、在WaterTextBox中写如下代码

using System;
using System.Drawing;
using System.Windows.Forms;

namespace WaterMarkTextBoxDemo
{
    public partial class WaterMarkTextBox : TextBox
    {
        private readonly Label lblwaterText = new Label();

        public WaterMarkTextBox()
        {
            InitializeComponent();
            lblwaterText.BorderStyle = BorderStyle.None;
            lblwaterText.Enabled = false;
            lblwaterText.BackColor = Color.White;
            lblwaterText.AutoSize = false;
            lblwaterText.Top = 1;
            lblwaterText.Left = 2;
            lblwaterText.FlatStyle = FlatStyle.System;
            Controls.Add(lblwaterText);
        }

        public string WaterText
        {
            get { return lblwaterText.Text; }
            set { lblwaterText.Text = value; }
        }

        public override string Text
        {
            set
            {
                lblwaterText.Visible = value == string.Empty;
                base.Text = value;
            }
            get
            {
                return base.Text;
            }
        }

        protected override void OnSizeChanged(EventArgs e)
        {
            if (Multiline && (ScrollBars == ScrollBars.Vertical || ScrollBars == ScrollBars.Both))
                lblwaterText.Width = Width - 20;
            else
                lblwaterText.Width = Width;
            lblwaterText.Height = Height - 2;
            base.OnSizeChanged(e);
        }

        protected override void OnTextChanged(EventArgs e)
        {
            lblwaterText.Visible = base.Text == string.Empty;
            base.OnTextChanged(e);
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            lblwaterText.Visible = false;
            base.OnMouseDown(e);
        }

        protected override void OnGotFocus(EventArgs e)
        {
            lblwaterText.Visible = base.Text == string.Empty;
            base.OnGotFocus(e);
        }


        protected override void OnLostFocus(EventArgs e)
        {
            lblwaterText.Visible = base.Text == string.Empty;
            base.OnLostFocus(e);
        }
    }
}

3、可以将其编译成dll文件，或者是直接写在项目下，具体代码请到点击打开链接下载