如何实现屏幕取词？

[gougou1]

如何实现类似于《金山词霸》的屏幕取词功能。运行该程序，将鼠标指针移动到文本框内的某个单词上，则在窗体下方的标签中就会显示出该单词。

[LoveBH]

从你的要求来看，输入信息是鼠标的位置，而输出信息是鼠标所在位置的单词。直接从鼠标的位置得到该位置的单词是很困难的。

通过SendMessage函数向RichTextBox控件发送EM_CHARFROMPOS消息，可以将鼠标在RichTextBox控件中的位置信息转换为字符的位置信息。这样，以该字符为中心，向前向后检索该单词的其他字符即可。

代码如下

Option Explicit
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
lParam As Any) As Long
Private Const EM_CHARFROMPOS& = &HD7
Private Type POINTAPI
X As Long
Y As Long
End Type

' Return the word the mouse is over.
Public Function RichWordOver(rch As RichTextBox, X As Single, Y As Single) As String
Dim pt As POINTAPI
Dim pos As Integer
Dim start_pos As Integer
Dim end_pos As Integer
Dim ch As String
Dim txt As String
Dim txtlen As Integer
'将鼠标位置的单位转换为像素
pt.X = X / Screen.TwipsPerPixelX
pt.Y = Y / Screen.TwipsPerPixelY
'得到字符的位置
pos = SendMessage(rch.hWnd, EM_CHARFROMPOS, 0&, pt)
If pos <= 0 Then Exit Function
'检索单词的第一个字符 Find the start of the word.
txt = rch.Text
For start_pos = pos To 1 Step -1
ch = Mid$(rch.Text, start_pos, 1)
'允许字符为数字、字母和下划线
If Not ((ch >= "0" And ch <= "9") Or _
(ch >= "a" And ch <= "z") Or _
(ch >= "A" And ch <= "Z") Or ch = "_") Then
Exit For
End If
Next start_pos
start_pos = start_pos + 1
'检索单词的第一个字符 Find the end of the word.
txtlen = Len(txt)
For end_pos = pos To txtlen
ch = Mid$(txt, end_pos, 1)
'允许字符为数字、字母和下划线
If Not ((ch >= "0" And ch <= "9") Or _
(ch >= "a" And ch <= "z") Or _
(ch >= "A" And ch <= "Z") Or ch = "_") Then
Exit For
End If
Next end_pos
end_pos = end_pos - 1
'取出单词
If start_pos <= end_pos Then
RichWordOver = Mid$(txt, start_pos, end_pos - start_pos + 1)
End If
End Function

Private Sub Form_Load()
RichTextBox1.Text = "Ready-To-Run Visual Basic Algorithms, Second Edition" & _
vbCrLf & vbCrLf & "Extend your applications with powerful algorithms written in Visual Basic. Sorting, searching, trees, hashing, advanced recursion, network algorithms, object-oriented programming, and much more. Visual Basic Algorithms updated and expanded for Visual Basic 6." & _
vbCrLf & vbCrLf & "http://www.vb-helper.com/vba.htm"
Label1.Caption = ""
End Sub

Private Sub RichTextBox1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim txt As String
txt = RichWordOver(RichTextBox1, X, Y)
If Label1.Caption <> txt Then
Label1.Caption = txt
End If
End Sub


欢迎光临电脑爱好者论坛 bbs.cfanclub.net

[tianyer]

楼上的方法正确，使用SendMessage就可以得到。不过他的代码长些。

Attribute VB_Name = "Module1"
Option Explicit

Public Const EM_CHARFROMPOS = &HD7
Public Const EM_GETLINECOUNT = &HBA
Public Const EM_GETLINE = &HC4
Public Const EM_LINEINDEX = &HBB
Public Const EM_LINELENGTH = &HC1

Declare Sub RtlMoveMemory Lib "KERNEL32" (lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)
Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
------------------------------------------------------------------------
VERSION 5.00
Begin VB.Form Form1
Caption = "读取鼠标所在位置的单词"
ClientHeight = 2352
ClientLeft = 60
ClientTop = 348
ClientWidth = 5160
LinkTopic = "Form1"
ScaleHeight = 196
ScaleMode = 3 'Pixel
ScaleWidth = 430
StartUpPosition = 3 '窗口缺省
Begin VB.TextBox Text1
BeginProperty Font
Name = "MS Serif"
Size = 12
Charset = 0
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 1815
Left = 240
MultiLine = -1 'True
ScrollBars = 2 'Vertical
TabIndex = 0
Text = "GetWord.frx":0000
Top = 240
Width = 4695
End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

Private Sub Text1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim pos As Long, lc As Long
Dim Line As Integer, CharPos As Integer

pos = X / Screen.TwipsPerPixelX + Y / Screen.TwipsPerPixelY * 65536
lc = SendMessage(Text1.hwnd, EM_CHARFROMPOS, 0, ByVal pos)

Line = lc \ 65536
CharPos = lc Mod 65536

MsgBox " = " & GetLine(Text1, Line) & vbCrLf & "单词= " & GetWord(Text1, CharPos)
End Sub

Function GetWord(txt As TextBox, pos As Integer) As String
Dim bArr() As Byte, pos1 As Integer, pos2 As Integer, i As Integer

bArr = StrConv(txt.Text, vbFromUnicode)
pos1 = 0: pos2 = UBound(bArr)


For i = pos - 1 To 0 Step -1
If IsDelimiter(bArr(i)) Then
pos1 = i + 1
Exit For
End If
Next


For i = pos To UBound(bArr)
If IsDelimiter(bArr(i)) Then
pos2 = i - 1
Exit For
End If
Next

If pos2 > pos1 Then
ReDim bArr2(pos2 - pos1) As Byte
For i = pos1 To pos2
bArr2(i - pos1) = bArr(i)
Next

GetWord = StrConv(bArr2, vbUnicode)
Else
GetWord = ""
End If
End Function

Function IsDelimiter(ByVal Char As Byte) As Boolean
Dim S As String

S = Chr(Char)
IsDelimiter = False
If S = " " Or S = "," Or S = "." Or S = "?" Or S = vbCr Or S = vbLf Then
IsDelimiter = True
End If
End Function

Function GetLine(txt As TextBox, ByVal Line As Integer) As String
Dim S As String, Length As Integer, pos As Long

GetLine = ""
pos = SendMessage(txt.hwnd, EM_LINEINDEX, Line, ByVal 0&)
Length = SendMessage(txt.hwnd, EM_LINELENGTH, pos, ByVal 0&)
S = String(Length, Chr(0))
RtlMoveMemory ByVal S, Length, 2
If SendMessage(Text1.hwnd, EM_GETLINE, Line, ByVal S) > 0 Then
GetLine = S
End If
End Function

Private Sub Text1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim pos As Long, lc As Long
Dim Line As Integer, CharPos As Integer

pos = X / Screen.TwipsPerPixelX + Y / Screen.TwipsPerPixelY * 65536
lc = SendMessage(Text1.hwnd, EM_CHARFROMPOS, 0, ByVal pos)

Line = lc \ 65536
CharPos = lc Mod 65536

Text1.ToolTipText = GetWord(Text1, CharPos)
End Sub