【发布时间】：2021-04-14 13:54:38
【问题描述】：
是否有办法防止只读RichRextBox 的光标（IBeam）在文本框获得焦点时闪烁？
我试图阻止来自WndProc 的WM_SETFOCUS 消息，但这会导致表单挂起。
if( m.Msg == 0x0007 ) return;
【问题讨论】：
标签： winforms richtextbox
【发布时间】：2021-04-14 13:54:38
【问题描述】：
您需要使用 Win32 API。以下是您可以在 VB 中执行的操作：
'API declares
Private Declare Function HideCaret Lib "user32" _
(ByVal hwnd As IntPtr) As Integer
Private Declare Function ShowCaret Lib "user32" _
(ByVal hwnd As IntPtr) As Integer
'hide the caret in myTextBox
Call HideCaret(myTextBox.Handle)
'show the caret back..
Call ShowCaret(myTextBox.Handle)
在 C# 中
[DllImport("user32.dll", EntryPoint = "ShowCaret")]
public static extern long ShowCaret(IntPtr hwnd);
[DllImport("user32.dll", EntryPoint = "HideCaret")]
public static extern long HideCaret(IntPtr hwnd);
然后拨打电话
HideCaret(richtextbox.Handle)
当你想隐藏它时。
【讨论】：
-
作为附录，我在事件
textbox.GotFocus中调用它时发现成功了@
只是说 Anirudh Goel 的答案不起作用（至少在 C# 中）。克拉还在那里闪烁：/
我找到了解决方案：http://www.experts-exchange.com/Programming/Languages/C_Sharp/Q_21896403.html
他的班级总是隐藏插入符号，这里有一个改进的，因此您可以选择隐藏或不隐藏插入符号。
如果你想隐藏不要忘记将 MustHideCaret 设置为 true
using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace Lm
{
public class RichTextBoxEx : RichTextBox
{
private readonly object mustHideCaretLocker = new object();
private bool mustHideCaret;
[DefaultValue(false)]
public bool MustHideCaret
{
get
{
lock (this.mustHideCaretLocker)
return this.mustHideCaret;
}
set
{
TabStop = false;
if (value)
SetHideCaret();
else
SetShowCaret();
}
}
[DllImport("user32.dll")]
private static extern int HideCaret(IntPtr hwnd);
[DllImport("user32.dll", EntryPoint = "ShowCaret")]
public static extern long ShowCaret(IntPtr hwnd);
public RichTextBoxEx()
{
}
private void SetHideCaret()
{
MouseDown += new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
MouseUp += new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
Resize += new EventHandler(ReadOnlyRichTextBox_Resize);
HideCaret(Handle);
lock (this.mustHideCaretLocker)
this.mustHideCaret = true;
}
private void SetShowCaret()
{
try
{
MouseDown -= new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
MouseUp -= new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
Resize -= new EventHandler(ReadOnlyRichTextBox_Resize);
}
catch
{
}
ShowCaret(Handle);
lock (this.mustHideCaretLocker)
this.mustHideCaret = false;
}
protected override void OnGotFocus(EventArgs e)
{
if (MustHideCaret)
HideCaret(Handle);
}
protected override void OnEnter(EventArgs e)
{
if (MustHideCaret)
HideCaret(Handle);
}
private void ReadOnlyRichTextBox_Mouse(object sender, System.Windows.Forms.MouseEventArgs e)
{
HideCaret(Handle);
}
private void ReadOnlyRichTextBox_Resize(object sender, System.EventArgs e)
{
HideCaret(Handle);
}
}
}
【讨论】：
更简单的方法：将此事件附加到 RichTextBox 的 Enter 事件中：
private void Control_Enter(object sender, EventArgs e) {
ActiveControl = null;
}
【讨论】：
-
这杀死了我表单中的所有控件。相反，我使用 ActiveControl =
.ActiveForm;这可以防止完全锁定。 -
@TheC4Fox 我正在使用它，仅将事件附加到 RichTextbox ENTER 事件。这可以防止控件通过鼠标单击或键盘 TAB 完全聚焦。当用户使用 TAB 键时，您可以通过更多努力使其定位到下一个控件。我稍微修改了答案以使其更清楚。
对我来说，Pedro77 的解决方案也不起作用...... 我已将该类修改为：
using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace Lm
{
public class RichTextBoxEx : RichTextBox
{
private readonly object mustHideCaretLocker = new object();
private bool mustHideCaret;
[DefaultValue(false)]
public bool MustHideCaret
{
get
{
lock (this.mustHideCaretLocker)
return this.mustHideCaret;
}
set
{
TabStop = false;
if (value)
SetHideCaret();
else
SetShowCaret();
}
}
[DllImport("user32.dll")]
private static extern int HideCaret(IntPtr hwnd);
[DllImport("user32.dll", EntryPoint = "ShowCaret")]
public static extern long ShowCaret(IntPtr hwnd);
public RichTextBoxEx()
{
}
private void SetHideCaret()
{
MouseDown += new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
MouseUp += new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
Resize += new EventHandler(ReadOnlyRichTextBox_Resize);
HideCaret(Handle);
lock (this.mustHideCaretLocker)
this.mustHideCaret = true;
}
private void SetShowCaret()
{
try
{
MouseDown -= new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
MouseUp -= new MouseEventHandler(ReadOnlyRichTextBox_Mouse);
Resize -= new EventHandler(ReadOnlyRichTextBox_Resize);
}
catch
{
}
ShowCaret(Handle);
lock (this.mustHideCaretLocker)
this.mustHideCaret = false;
}
protected override void OnGotFocus(EventArgs e)
{
if (MustHideCaret)
{
HideCaret(Handle);
this.Parent.Focus();//here we select parent control in my case it is panel
}
}
protected override void OnEnter(EventArgs e)
{
if (MustHideCaret)
HideCaret(Handle);
}
private void ReadOnlyRichTextBox_Mouse(object sender, System.Windows.Forms.MouseEventArgs e)
{
HideCaret(Handle);
}
private void ReadOnlyRichTextBox_Resize(object sender, System.EventArgs e)
{
HideCaret(Handle);
}
}
}
然后将我的 RichTextBoxEx 放入（内部）面板控件... 修复了鼠标单击时插入符号闪烁的问题...
【讨论】：
经过多次尝试和错误，我找到了简单的解决方案。
在表单的“加载”子例程中，添加以下行：
AddFocusHandlers(Me)
然后将以下内容添加到表单代码的底部。在“HideCaret”例程中规定您希望此“阻止进入”发生的控件 （我列出了属于我的表单的三个文本框）：
Private Sub AddFocusHandlers(ByVal parentCtr As Control)
Dim ctr As Control
For Each ctr In parentCtr.Controls
AddHandler ctr.LostFocus, AddressOf meLostFocus
AddFocusHandlers(ctr)
Next
End Sub
Private Sub meLostFocus(ByVal sender As Object, ByVal e As System.EventArgs)
LastFocused = DirectCast(sender, Control)
End Sub
'This routine will activate each time any of the listed controls are entered.
Private Sub HideCaret(sender As Object, e As EventArgs) _
Handles tbDate.Enter, tbAttachments.Enter, tbTemplate.Enter
LastFocused.Select()
End Sub
最后放置在表单代码的顶部（在类名和第一个子或函数之间：
Private LastFocused As Control 'Control which previously had focus
然后，当用户单击“HideCaret”例程中控件列表中显示的任何控件时，光标只会停留在先前选择的控件中。 VB.Net 不是很棒吗？您几乎可以实现您认为不可能的任何事情。
【讨论】：