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Deflate StringCompresses a string using the Deflate compression algorithm. The functionality in this example is available in pre-release only:
Dim compress As New Chilkat.Compression() ' Any string argument automatically begins a 30-day trial. Dim success As Boolean success = compress.UnlockComponent("30-day trial") If (success <> true) Then MsgBox("Compression component unlock failed") Exit Sub End If compress.Algorithm = "deflate" Dim strData As String Dim i As Long ' Create a long string to deflate. strData = "abcdefg1122334455667788" strData = strData & vbCrLf For i = 0 To 99 strData = strData & "abcdefg1122334455667788" strData = strData & vbCrLf Next ' Depending on the programming language, the string ' may be Unicode. Tell the component to convert to ' ansi (1-byte/char) prior to compression: compress.Charset = "ansi" ' Compressed data is binary, meaning that all byte values ' from 0 to 255 are possible. The result would not be ' a printable string. To receive a printable string (us-ascii), ' the resultant compressed data should be encoded using ' an encoding such as base64. Set the EncodingMode ' property to determine the output encoding: ' (Valid choices are "base64", "hex", "url", and others) compress.EncodingMode = "base64" ' Note: Base64 encoding expands the compressed data by ' 4/3rds because each 3 bytes of binary data are represented ' by 4 printable chars. Hex, for example, doubles the output ' size because each byte is represented by 2 printable chars. ' Deflate the string: Dim deflatedStr As String deflatedStr = compress.CompressStringENC(strData) If (deflatedStr = vbNullString ) Then MsgBox(compress.LastErrorText) Exit Sub End If ' Display the deflated string. ' The result will be: ' S0xKTklNSzc0NDIyNjYxMTU1MzM3t7Dg5UoclRiVGJUYlRiVGJUYlRiVGJUYchIA TextBox1.Text = TextBox1.Text & deflatedStr & vbCrLf ' Decompress back to the original: Dim strOriginal As String strOriginal = compress.DecompressStringENC(deflatedStr) ' Display the uncompressed original: TextBox1.Text = TextBox1.Text & "--- Original ---" & vbCrLf TextBox1.Text = TextBox1.Text & strOriginal & vbCrLf |
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