Read、ReadText、Write 和 WriteText 方法示例 (VB)
此示例演示如何将文本框的内容读入文本 Stream 和二进制 Stream。 显示的其他属性和方法包括 Position、Size、Charset 和 SetEOS。
'BeginReadVB
Private Sub cmdRead_Click()
On Error GoTo ErrorHandler
'Declare variables
Dim objStream As Stream
Dim varA As Variant
Dim bytA() As Byte
Dim i As Integer
Dim strBytes As String
'Instantiate and Open Stream
Set objStream = New Stream
objStream.Open
'Write the text content of a textbox to the stream
If Text1.Text = "" Then
Err.Raise 1, , "The text field is blank."
End If
objStream.WriteText Text1.Text
'Display the text contents and size of the stream
objStream.Position = 0
Debug.Print "Default text:"
Debug.Print objStream.ReadText
Debug.Print objStream.Size
'Switch character set and display
objStream.Position = 0
objStream.Charset = "Windows-1252"
Debug.Print "New Charset text:"
Debug.Print objStream.ReadText
Debug.Print objStream.Size
'Switch to a binary stream and display
objStream.Position = 0
objStream.Type = adTypeBinary
Debug.Print "Binary:"
Debug.Print objStream.Read
Debug.Print objStream.Size
'Load an array of bytes with the text box text
ReDim bytA(Len(Text1.Text))
For i = 1 To Len(Text1.Text)
bytA(i - 1) = CByte(Asc(Mid(Text1.Text, i, 1)))
Next
'Write the buffer to the binary stream and display
objStream.Position = 0
objStream.Write bytA()
objStream.SetEOS
objStream.Position = 0
Debug.Print "Binary after Write:"
Debug.Print objStream.Read
Debug.Print objStream.Size
'Switch back to a text stream and display
Debug.Print "Translated back:"
objStream.Position = 0
objStream.Type = adTypeText
Debug.Print objStream.ReadText
Debug.Print objStream.Size
' clean up
objStream.Close
Set objStream = Nothing
Exit Sub
ErrorHandler:
' clean up
If Not objStream Is Nothing Then
If objStream.State = adStateOpen Then objStream.Close
End If
Set objStream = Nothing
If Err <> 0 Then
MsgBox Err.Source & "-->" & Err.Description, , "Error"
End If
End Sub
'EndReadVB
另请参阅
Charset 属性 (ADO)
Position 属性 (ADO)
Read 方法
ReadText 方法
SetEOS 方法
Size 属性(ADO 流)
流对象 (ADO)
Write 方法
WriteText 方法