如何匹配mysql数据库中的指纹fmd [英] How can I match a fingerprint fmd from mysql database
问题描述
您好，抱歉我的英语不好。我是印度尼西亚SMK的学生，我想为我的学校制作管理系统，我使用U Are U From Digital Persona作为学生考勤系统，我初学VB.Net与Digital Persona U接口是U 4500问题是，我不知道错误是什么，我不知道如何反序列化和序列化FMD到MySQL数据库。我的数据库数据类型是LONGBLOB。我使用此代码进行序列化
cmd = 新 MySqlCommand（< span class =code-string> 插入finger_data（finger）值（@jari），conn）
使用 cmd
.Parameters.AddWithValue（ @ jari ，Fmd.SerializeXml（resultConversion.Data））
.ExecuteNonQuery（）
结束 使用
当我将序列化fmd存储到数据库工作时。我不知道如何反序列化。
我尝试过：
我试过这个代码从数据库反序列化fmd。我收到此错误消息System.Data.dll中发生类型'System.IndexOutOfRangeException'的未处理异常
附加信息：位置1没有行。
这是我的反序列化代码。我已经试了很长时间了...所以任何人都可以帮助我...谢谢之前... < br $> b $ b
公共 Sub OnCaptured（ ByVal captureResult As CaptureResult）
如果 不 _sender.CheckCaptureResult（captureResult）那么
返回
结束 如果
SendMessage（Action.SendMessage， 指纹已被捕获）
Dim resultConversion 正如 DataResult（ Of Fmd）= FeatureExtraction.CreateFmdFromFid（captureResult.Data，Constants.Formats.Fmd.ANSI）
如果 captureResult.ResultCode<> Constants.ResultCode.DP_SUCCESS 然后
_sender.Reset = True
抛出 新异常（captureResult.ResultCode.ToString（））
结束 如果
如果 count = 0 然后
firstFinger = resultConversion.Data
count + = 1
SendMessage（Action.SendMessage， 现在放置相同的或读取器上的其他手指。）
ElseIf count = 1 然后
secondFinger = resultConversion.D ata
count + = 1
SendMessage（Action.SendMessage， 现在将相同或不同的手指放在阅读器上。）
ElseIf count = 2 然后
AnyFinger = resultConversion.Data
Dim fmds As Fmd（）= 新 Fmd（ 1 ）{}
fmds（ 0 ）= firstFinger
fmds（ 1 ）= secondFinger
Dim thresholdScore 正如 整数 = PROBABILITY_ONE * 1 / 10000
Dim ds As 新 DataSet
adt = 新 MySqlDataAdapter（ select * from finger_data where finger，conn）
adt.Fill（ds， finger_data）
Dim A As 整数 = ds.Tables（ finger_data ）。行（ 1 ）。项目（ 0 ）//我有错误 此行
Dim Y < span class =code-keyword>作为 字节（）= DirectCast （ds.Tables（ finger_data）。行（ 0 ）。项目（ 2 ），字节（））
Dim 值 As < span class =code-keyword> String = System.Text.Encoding.Unicode.GetString（Y）
Dim X = Fmd。 DeserializeXml（value）
Dim identifyResult As IdentifyResult = Comparison.Identify（X ， 0 ，fmds，thresholdScore， 2 ）
如果 identifyResult.ResultCode<> Constants.ResultCode.DP_SUCCESS 然后
_sender.Reset = True
抛出 新异常（identifyResult.ResultCode.ToString（））
结束 如果
SendMessage（Action.SendMessage， 标识结果 + identifyResult.Indexes.Length.ToString（））
SendMessage（Action.SendMessage， 放置索引）
count = 0
结束 如果
结束 Sub
0 。）
根据后续行，您希望从表中访问第一个行，因此您需要将行索引更改为 0 。
但是，在尝试访问之前，还应检查查询是否返回了一行。
adt.Fill（ds， finger_data）
如果 ds.Tables（ finger_data).Rows.Count = 0 然后
' 没有返回任何行。在此处向用户显示错误消息。
否则
Dim 作为 整数 = ds.Tables（ finger_data）。行（ 0 ）。项目（ 0 ）
...
结束 如果
Hello, Sorry for my Bad English. Im a student in indonesian SMK which i want to make management system for my school, I used U Are U From Digital Persona for Student Attendance System and i beginner on VB.Net interfacing with Digital Persona U Are U 4500 The problem is, i dont know what the error and i dont know how to Deserialize and Serialize An FMD to MySQL Database. My database datatype is LONGBLOB. I Used this code for serialize
cmd = New MySqlCommand("insert into finger_data(finger) values(@jari)", conn)
With cmd
.Parameters.AddWithValue("@jari", Fmd.SerializeXml(resultConversion.Data))
.ExecuteNonQuery()
End With
When i stored the serialize fmd to database is work. And i dont know how to Deserialize.
What I have tried:
I Tried this code for Deserialize fmd from database. And i get this error message "An unhandled exception of type 'System.IndexOutOfRangeException' occurred in System.Data.dll
Additional information: There is no row at position 1.
This My Code For Deserialize. I have tried for a long days for this... So Anyone can help me please... Thanks before...
Public Sub OnCaptured(ByVal captureResult As CaptureResult)
If Not _sender.CheckCaptureResult(captureResult) Then
Return
End If
SendMessage(Action.SendMessage, "The Fingerprint Was Captured")
Dim resultConversion As DataResult(Of Fmd) = FeatureExtraction.CreateFmdFromFid(captureResult.Data, Constants.Formats.Fmd.ANSI)
If captureResult.ResultCode <> Constants.ResultCode.DP_SUCCESS Then
_sender.Reset = True
Throw New Exception(captureResult.ResultCode.ToString())
End If
If count = 0 Then
firstFinger = resultConversion.Data
count += 1
SendMessage(Action.SendMessage, "Now place the same or a different finger on the reader.")
ElseIf count = 1 Then
secondFinger = resultConversion.Data
count += 1
SendMessage(Action.SendMessage, "Now place the same or a different finger on the reader.")
ElseIf count = 2 Then
AnyFinger = resultConversion.Data
Dim fmds As Fmd() = New Fmd(1) {}
fmds(0) = firstFinger
fmds(1) = secondFinger
Dim thresholdScore As Integer = PROBABILITY_ONE * 1 / 10000
Dim ds As New DataSet
adt = New MySqlDataAdapter("select * from finger_data where finger", conn)
adt.Fill(ds, "finger_data")
Dim A As Integer = ds.Tables("finger_data").Rows(1).Item(0) //I got Error on this Line
Dim Y As Byte() = DirectCast(ds.Tables("finger_data").Rows(0).Item(2), Byte())
Dim value As String = System.Text.Encoding.Unicode.GetString(Y)
Dim X = Fmd.DeserializeXml(value)
Dim identifyResult As IdentifyResult = Comparison.Identify(X, 0, fmds, thresholdScore, 2)
If identifyResult.ResultCode <> Constants.ResultCode.DP_SUCCESS Then
_sender.Reset = True
Throw New Exception(identifyResult.ResultCode.ToString())
End If
SendMessage(Action.SendMessage, "Result Of The Identification " + identifyResult.Indexes.Length.ToString())
SendMessage(Action.SendMessage, "Place Index")
count = 0
End If
End SubThe error message is quite clear - you're trying to access the second row of the table, but the table doesn't have two rows. (Remember, the collections are zero-based, so the first row is at index0.)
Based on the subsequent line, you want to access the first row from the table, so you need to change the row index to0.
However, you should also check that the query returned a row before you try to access it.
adt.Fill(ds, "finger_data") If ds.Tables("finger_data").Rows.Count = 0 Then ' No rows returned. Show an error message to the user here. Else Dim A As Integer = ds.Tables("finger_data").Rows(0).Item(0) ... End If
这篇关于如何匹配mysql数据库中的指纹fmd的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
