无法为 kryptontextbox 设置提示横幅

Question

我尝试使用以下代码为 kryptontextbox 设置提示横幅

Imports System.Runtime.InteropServices

Public Class Form1

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
       SetCueText(KryptonTextBox1.Handle, "Enter Name here")
    End Sub
End Class

Public Module CueBannerText
    <DllImport("user32.dll", CharSet:=CharSet.Auto)> _
    Private Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wParam As Integer, <MarshalAs(UnmanagedType.LPWStr)> ByVal lParam As String) As Int32
    End Function
    Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As IntPtr, ByVal hWnd2 As IntPtr, ByVal lpsz1 As String, ByVal lpsz2 As String) As IntPtr
    Private Const EM_SETCUEBANNER As Integer = &H1501

    Public Sub SetCueText(hWnd As IntPtr, text As String)
      if Not hWnd = IntPtr.Zero Then
         SendMessage(hWnd, EM_SETCUEBANNER, 0, text)
      End If
    End Sub
End Module

但是，文本没有设置。我该如何解决这个问题

Answer 1

EM_SETCUEBANNER 适用于TextBox 控件。 KryptonTextBox 实际上是一个复合 Control，其中包含一个 TextBox。

TextBox 使用 TextBox 属性公开。您可以使用KryptonTextBox1.TextBox.Handle 发送EM_SETCUEBANNER 消息。

要查看组件的源代码，请查看GitHub repository。下面是相关部分代码：

public class KryptonTextBox : VisualControlBase, IContainedInputControl
{
    //...
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
    [EditorBrowsable(EditorBrowsableState.Always)]
    [Browsable(false)]
    public TextBox TextBox
    {
        get { return _textBox; }
    }
    //...
}