vb.net数据列表 vbnet操作数据库

用vb.net 怎样建立一个mdb数据库及一张表

首先在项目的VB.NET界面，使用菜单【项目】--【添加引用】--【COM】

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选择  Microsoft ADO Ext. 2.x for DDL and Security

然后单击【确定】，完成引用。

完整代码如下：

Imports ADOX

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

'创建空的access数据库文件--数据库文件.mdb，密码为123

Dim Mycat As Catalog = New Catalog()

Mycat.Create("Provider=Microsoft.Jet.OLEDB.4.0;Jet OLEDB:Engine Type=5;Data Source= 数据库文件.mdb;Jet OLEDB:Database Password=123")

'以下代码创建一个名为“实验数据表”

Dim MyTable As ADOX.Table = New ADOX.Table         '定义新表

MyTable.Name = "实验数据表"    '表命名

'给表“实验数据表” 创建一个字符串字段，字段名“姓名”

MyTable.Columns.Append("姓名", , ADOX.DataTypeEnum.adWChar)

'给表“实验数据表” 创建一个整数字段，字段名“学号”

MyTable.Columns.Append("学号", ADOX.DataTypeEnum.adInteger)    '追加一个数字型字段

'给字段“学号”创建一个主键“PimaryKey_Field”        

MyTable.Keys.Append("学号", ADOX.KeyTypeEnum.adKeyPrimary, "学号")

Mycat.Tables.Append(MyTable) '把所有的新字段追加到表

MyTable = Nothing

Mycat = Nothing

End Sub

End Class

VB.NET大量数据列表化实时显示用什么控件比较好

接收数据时，使用一个 Label 显示就行了。而且跳过一些数据再显示，例如一秒钟才显示一个数据。

你应该把精力放到领导（或者用户）的意图上，不要纠结技术上的 ListBox。

VB.NET数组或数组列表

Dim TestItem() As String = New String() {"Pickle", "Pineapple", "Papaya"} '创建数组 并赋值

Dim TestShoppingList As String = Join(TestItem, " = ") 'Join 就是字符联接函数 后面的 =号 可选 为空值就把所有的字符串在一起 本例用=号 就是把 所有数组的值用 =号联接起来

MsgBox(TestShoppingList) '显示结果值

'这例子 就一个函数可以解决 就不发图片了

希望能帮到你 你慢慢研究吧 有问题可以找我

看到的 爱好者 多顶我一下 谢谢呵呵

利用VB.NET实现导出DataTable数据到excel中，各位大侠帮帮忙，最好有源码，谢谢，江湖救急

刚好写了个Helper类，你试验一下DataTable2Exce(这个方法代码如下：

Imports System.IO

Imports System.Data

Imports System.Data.OleDb

Public MustInherit Class ExcelHelper

Private Shared Function buildConnStr(excelFilePath As String) As String

Dim excelFileInfo As New System.IO.FileInfo(excelFilePath)

Dim constr As String

If excelFileInfo.Extension = ".xlsx" Then

constr = String.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 12.0 Xml;HDR=YES;IMEX=1'", excelFilePath)

Else

constr = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};Extended Properties='Excel 8.0;HDR=Yes;IMEX=1'", excelFilePath)

End If

Return constr

End Function

'将datatable导入到excel

Public Shared Function DataTable2Excel(dt As DataTable, excelFilePath As String) As Boolean

If File.Exists(excelFilePath) Then

Throw New Exception("该文件已经存在！")

End If

If dt.TableName.Trim.Length = 0 Or dt.TableName.ToLower = "table" Then

dt.TableName = "Sheet1"

End If

Dim colCount As Integer = dt.Columns.Count

Dim pa(colCount - 1) As OleDb.OleDbParameter

Dim tableStructStr As String = "Create Table " dt.TableName "("

Dim connString As String = buildConnStr(excelFilePath)

Dim objconn As New OleDbConnection(connString)

Dim objcmd As New OleDbCommand

objcmd.Connection = objconn

Dim dataTypeList As New ArrayList

dataTypeList.Add("System.Decimal")

dataTypeList.Add("System.Double")

dataTypeList.Add("System.Int16")

dataTypeList.Add("System.Int32")

dataTypeList.Add("System.Int64")

dataTypeList.Add("System.Single")

Dim i As Integer = 0

For Each col As DataColumn In dt.Columns

If dataTypeList.IndexOf(col.GetType.ToString) 0 Then

pa(i) = New OleDbParameter("@" col.ColumnName, OleDbType.Double)

objcmd.Parameters.Add(pa(i))

If i + 1 = colCount Then

tableStructStr += col.ColumnName + " double)"

Else

tableStructStr += col.ColumnName + " double,"

End If

Else

pa(i) = New OleDbParameter("@" col.ColumnName, OleDbType.VarChar)

objcmd.Parameters.Add(pa(i))

If i + 1 = colCount Then

tableStructStr += col.ColumnName + " VarChar)"

Else

tableStructStr += col.ColumnName + " VarChar,"

End If

End If

i += 1

Next

Try

objcmd.CommandText = tableStructStr

If objconn.State = ConnectionState.Closed Then objconn.Open()

objcmd.ExecuteNonQuery()

Catch ex As Exception

Throw ex

End Try

Dim InsertSql_1 As String = "Insert into " + dt.TableName + " ("

Dim InsertSql_2 As String = " Values ("

Dim InsertSql As String = ""

For colID As Integer = 0 To colCount - 1 Step 1

If colID + 1 = colCount Then

InsertSql_1 += dt.Columns(colID).ColumnName ")"

InsertSql_2 += "@" + dt.Columns(colID).ColumnName + ")"

Else

InsertSql_1 += dt.Columns(colID).ColumnName + ","

InsertSql_2 += "@" + dt.Columns(colID).ColumnName + ","

End If

Next

InsertSql = InsertSql_1 + InsertSql_2

For rowID As Integer = 0 To dt.Rows.Count - 1 Step 1

For colID = 0 To dt.Columns.Count - 1

If pa(colID).DbType = DbType.Double And dt.Rows(rowID)(colID).ToString.Trim = "" Then

pa(colID).Value = 0

Else

pa(colID).Value = dt.Rows(rowID)(colID).ToString.Trim

End If

Next

Try

objcmd.CommandText = InsertSql

objcmd.ExecuteNonQuery()

Catch ex As Exception

Throw ex

End Try

Next

Try

If objconn.State = ConnectionState.Open Then objconn.Close()

Catch exp As Exception

Throw exp

End Try

Return True

End Function

' 获取Excel文件数据表列表Sheets

Public Shared Function GetExcelTables(ExcelFileName As String) As ArrayList

'Dim sheets As New List(Of String)

'conn.Open()

'Dim dt As DataTable = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, Nothing)

'For Each r In dt.Rows

' sheets.Add(r("TABLE_NAME"))

'Next

'conn.Close()

'Return sheets

Dim dt As DataTable

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

Return Nothing

End If

Dim tableList As New ArrayList

Using conn As OleDbConnection = New OleDbConnection(buildConnStr(ExcelFileName))

Try

conn.Open()

dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, New Object() {Nothing, Nothing, Nothing, "TABLE"})

Catch ex As Exception

Throw ex

End Try

For i As Integer = 0 To dt.Rows.Count - 1

Dim tableName As String = dt.Rows(i)(2).ToString.Trim.TrimEnd("$")

If tableList.IndexOf(tableName) 0 Then tableList.Add(tableName)

Next

End Using

Return tableList

End Function

'将Excel文件导出至DataTable(第一行作为表头)

Public Shared Function InputFromExcel(ExcelFileName As String, TableName As String) As DataTable

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

End If

Dim tableList As ArrayList = GetExcelTables(ExcelFileName)

If tableList.IndexOf(TableName) 0 Then

TableName = tableList(0).ToString.Trim

End If

Dim dt As New DataTable

Dim conn As New OleDbConnection(buildConnStr(ExcelFileName))

Dim cmd As New OleDbCommand("select * from [" TableName "$]", conn) '调试是否需要$

Dim adapter As New OleDbDataAdapter(cmd)

Try

If conn.State = ConnectionState.Closed Then conn.Open()

adapter.Fill(dt)

Catch ex As Exception

Throw ex

Finally

If conn.State = ConnectionState.Open Then conn.Close()

End Try

Return dt

End Function

'查询excel文件中的一个数据

Public Shared Function ReadOneDataFromExcel(ExcelFileName As String, TableName As String, sql As String) As Object

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

End If

Dim tableList As ArrayList = GetExcelTables(ExcelFileName)

If tableList.IndexOf(TableName) 0 Then

TableName = tableList(0).ToString.Trim

End If

Dim dt As New DataTable

Dim conn As New OleDbConnection(buildConnStr(ExcelFileName))

Dim cmd As New OleDbCommand(sql, conn) '调试是否需要$

Dim ret As Object

Try

If conn.State = ConnectionState.Closed Then conn.Open()

ret = cmd.ExecuteScalar()

Catch ex As Exception

Throw ex

Finally

If conn.State = ConnectionState.Open Then conn.Close()

End Try

Return ret

End Function

'获取Excel文件指定数据表的数据列表columnNames

Public Shared Function GetExcelTableColumns(ExcelFileName As String, TableName As String) As ArrayList

Dim dt As DataTable

If Not File.Exists(ExcelFileName) Then

Throw New Exception("指定的Excel文件不存在")

Return Nothing

End If

Dim ColList As New ArrayList

Using conn As OleDbConnection = New OleDbConnection(buildConnStr(ExcelFileName))

Try

conn.Open()

dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, New Object() {Nothing, Nothing, TableName, Nothing})

Catch ex As Exception

Throw ex

End Try

For i As Integer = 0 To dt.Rows.Count - 1

Dim ColName = dt.Rows(i)("Column_Name").ToString().Trim()

ColList.Add(ColName)

Next

End Using

Return ColList

End Function

End Class

vb.net中的list怎样用数组添加列表项

list1.additem j 意思就是把j添加至list1列表中,这是在一个for 循环中，循环了10次，添加了10次 j，即 list1 中 有10列分别为：1,3,6,10,15,21,28,36,45,55

下面又来了一个循环， list1.removeitem 删除列，删除的是 list1.listcount - i ，list1.listcount 就是总列数为10，减去 i ，i 是1到4，即10-1，9-2，8-3，7-4 每减掉一次，list1.listcount 就少了一条记录。

(注意，list1.listcount-1 是最后一条记录)

减掉了第 9，7，5，3列

剩余为 1,3,6,15,28,45

结果为：3,15,28

'ListCount返回列表框中的项目总数

'ListCount-1是列表框中最后一个项目的索引号

'亏你提醒了，我写错了，上面修改了，第一个索引为0，最后一个为9.

'也就是，问题所问的第二列的索引为1，第四列的索引为3...

VB.Net中datagridview如何数据表

你可以在SQL语句里面把列名变为中文名 再放到DATAGRID里面啊

如 SELECT 字段1 AS 某某1 ,字段2 AS 某某2 FROM 某表

你的串号我已经记下，采纳后我会帮你制作