using System; using System.Drawing; using System.Runtime.InteropServices; using System.Windows.Forms; namespace KK.WatermarkTextBox { public partial class WatermarkTextBox : TextBox { private const uint ECM_FIRST = 0x1500; private const uint EM_SETCUEBANNER = ECM_FIRST + 1; [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)] static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, uint wParam, [MarshalAs(UnmanagedType.LPWStr)] string lParam); public WatermarkTextBox() { InitializeComponent(); } private string watermarkText; public string WatermarkText { get { return watermarkText; } set { watermarkText = value; SetWatermark(watermarkText); } } private void SetWatermark(string watermarkText) { SendMessage(this.Handle, EM_SETCUEBANNER, 0, watermarkText); } } }
运行效果如下所示:
博客内容主要用于日常学习记录,内容比较随意,如有问题,还需谅解!!!