vb System.Buffer.BlockCopy类(方法)实例源码

Module Example
    ' Display the individual bytes in the array in hexadecimal.
    Sub DisplayArray(arr As Array, name As String)
        Console.Write("{0,11}:", name)
        For ctr As Integer = 0 to arr.Length - 1
            Dim bytes() As Byte = BitConverter.GetBytes(arr(ctr))
            For Each byteValue As Byte In bytes
               Console.Write(" {0:X2}", byteValue)
            Next
        Next
        Console.WriteLine()
    End Sub

    ' Display the individual array element values in hexadecimal.
    Sub DisplayArrayValues(arr As Array, name As String)
       ' Get the length of one element in the array.
       Dim elementLength As Integer = Buffer.ByteLength(arr) / arr.Length
       Dim formatString As String = String.Format(" {{0:X{0}}}", 2 * elementLength)
       Console.Write("{0,11}:", name)
       For ctr As Integer = 0 to arr.Length - 1
         Console.Write(formatString, arr(ctr))
       Next
       Console.WriteLine()  
    End Sub
    
    Sub Main()
       Console.WindowWidth = 120
        ' These are source and destination arrays for BlockCopy.
        Dim src()  As Short = { 258, 259, 260, 261, 262, 263, 264, _
                                 265, 266, 267, 268, 269, 270 }
        Dim dest() As Long = { 17, 18, 19, 20 }

        ' Display the initial value of the arrays in memory.
        Console.WriteLine( "Initial values of arrays:")
        Console.WriteLine("   Array values as Bytes:") 
        DisplayArray(src, "src" )
        DisplayArray(dest, "dest" )
        Console.WriteLine("   Array values:")
        DisplayArrayValues(src, "src")
        DisplayArrayValues(dest, "dest")
        Console.WriteLine()

        ' Copy bytes 5-10 from source to index 7 in destination and display the result.
        Buffer.BlockCopy( src, 5, dest, 7, 6 )
        Console.WriteLine("Buffer.BlockCopy(src, 5, dest, 7, 6 )")
        Console.WriteLine("   Array values as Bytes:")
        DisplayArray(src, "src")
        DisplayArray(dest, "dest")
        Console.WriteLine("   Array values:")
        DisplayArrayValues(src, "src")
        DisplayArrayValues(dest, "dest")
        Console.WriteLine()
        
        ' Copy bytes 16-20 from source to index 22 in destination and display the result. 
        Buffer.BlockCopy( src, 16, dest, 22, 5 )
        Console.WriteLine("Buffer.BlockCopy(src, 16, dest, 22, 5)")
        Console.WriteLine("   Array values as Bytes:")
        DisplayArray(src, "src")
        DisplayArray(dest, "dest")
        Console.WriteLine("   Array values:")
        DisplayArrayValues(src, "src")
        DisplayArrayValues(dest, "dest")
        Console.WriteLine()
         
        ' Copy overlapping range of bytes 4-10 to index 5 in source.
        Buffer.BlockCopy( src, 4, src, 5, 7 )
        Console.WriteLine("Buffer.BlockCopy( src, 4, src, 5, 7)")
        Console.WriteLine("   Array values as Bytes:")
        DisplayArray(src, "src")
        DisplayArray(dest, "dest")
        Console.WriteLine("   Array values:")
        DisplayArrayValues(src, "src")
        DisplayArrayValues(dest, "dest")
        Console.WriteLine()
        
        ' Copy overlapping range of bytes 16-22 to index 15 in source. 
        Buffer.BlockCopy(src, 16, src, 15, 7)
        Console.WriteLine("Buffer.BlockCopy( src, 16, src, 15, 7)")
        Console.WriteLine("   Array values as Bytes:")
        DisplayArray(src, "src")
        DisplayArray(dest, "dest")
        Console.WriteLine("   Array values:")
        DisplayArrayValues(src, "src")
        DisplayArrayValues(dest, "dest")
    End Sub 
End Module

Const INT_SIZE As Integer = 4
Dim arr() As Integer = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 }
Buffer.BlockCopy(arr, 0 * INT_SIZE, arr, 3 * INT_SIZE, 4 * INT_SIZE)
For Each value As Integer In arr
   Console.Write("{0}  ", value)
Next

Const INT_SIZE As Integer = 4
Dim arr() As Integer = { 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 }
Buffer.BlockCopy(arr, 3 * INT_SIZE, arr, 0 * INT_SIZE, 4 * INT_SIZE)
For Each value As Integer In arr
   Console.Write("{0}  ", value)
Next