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首先引入System.IO命名空间
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Imports System.IO
然后使用文件流来读入数组：
Dim bytes() As Byte
Using fs As New FileStream(文件路径,FileMode.Open)
ReDim bytes(fs.Length-1)
fs.Read(bytes,0,fs.Length)
fs.Close()
End Using
这样bytes就是整个文件的所有字节了
从字节生成Image：
Dim img As Image = Image.FromStream(New MemoryStream(bytes))
img就是图片了
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim MyStream As New System.IO.MemoryStream
Me.PictureBox1.Image.Save(MyStream, System.Drawing.Imaging.ImageFormat.Jpeg)
Dim MyBytes(MyStream.Length) As Byte
MyStream.Read(MyBytes, 0, MyStream.Length)
MyStream.Close()
Dim strText As String
strText = BitConverter.ToString(MyBytes)
Me.TextBox1.Text = strText
End Sub
'容易，用api，查一查SetBitmapBits
'新建工程，增加一个 command button ， 一个 picture box , 将图片加载到 picture box.
'将代码粘贴到 Form1
Private Type BITMAP
bmType As Long
bmWidth As Long
bmHeight As Long
bmWidthBytes As Long
bmPlanes As Integer
bmBitsPixel As Integer
bmBits As Long
End Type
Private Declare Function GetObject Lib "gdi32" Alias "GetObjectA" (ByVal hObject As Long, ByVal nCount As Long, lpObject As Any) As Long
Private Declare Function GetBitmapBits Lib "gdi32" (ByVal hBitmap As Long, ByVal dwCount As Long, lpBits As Any) As Long
Private Declare Function SetBitmapBits Lib "gdi32" (ByVal hBitmap As Long, ByVal dwCount As Long, lpBits As Any) As Long
Dim PicBits() As Byte, PicInfo As BITMAP, Cnt As Long
Private Sub Command1_Click()
'Get information (such as height and width) about the picturebox
GetObject Picture1.Image, Len(PicInfo), PicInfo
'reallocate storage space
ReDim PicBits(1 To PicInfo.bmWidth * PicInfo.bmHeight * 3) As Byte
'Copy the bitmapbits to the array
GetBitmapBits Picture1.Image, UBound(PicBits), PicBits(1)
'Invert the bits
For Cnt = 1 To UBound(PicBits)
PicBits(Cnt) = 255 - PicBits(Cnt)
Next Cnt
'Set the bits back to the picture
SetBitmapBits Picture1.Image, UBound(PicBits), PicBits(1)
'refresh
Picture1.Refresh
End Sub
VB.NET打开二进制文件用fileopen完成，打开二进制文件的形式为：openmode.binary
读取二进制文件用的是fileget方法，写入二进制文件用的是fileput方法。
应用示例：将一批随机数保存在一个dat文件中，然后再将其提取到文本框中。
二进制文件的读写一批随机数的存取，程序为：
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim x, i, fn As Integer
Dim s As String = ""
fn = FreeFile()
FileOpen(fn, "d:\data.dat", OpenMode.Binary)
For i = 1 To 8
x = Int(Rnd() * 100)
s = s + Str(x)
FilePut(fn, x)
Next
FileClose(fn)
TextBox1.Text = s
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim x, fn As Integer
Dim s As String = ""
fn = FreeFile()
FileOpen(fn, "d:\data.dat", OpenMode.Binary)
Do While Not EOF(fn)
FileGet(fn, x)
s = s + Str(x) + " "
Loop
FileClose(fn)
TextBox1.Text = s
End Sub