将数据绑定到DataGridView [英] Binding Data to DataGridView

问题描述

我有一些代码从MS SQL Server中存储过程中加载数据，然后将数据加载到datagridview，这样可以正常工作。我想要的是将连接/加载数据的代码放在我的数据库类中，然后将与datagridview相关联的所有内容存储在我的表单中，但是我遇到了将绑定源的内容从数据库传递到表单的问题

Form1

 类Form1 
 
 Dim myDatabaseObj As New Class1（）
 Dim bindingSource1 As New BindingSource（）
 Dim connectString As New SqlConnection 
 Dim objDataAdapter As New SqlDataAdapter 
 Dim table As New DataTable（）
 Dim tabletest As New DataTable（）
 
 Private Sub loadCompanyList（）
尝试
 Me.dgv_CompanyList.DataSource = Me.bindingSource1 
 getCompanyList（）
 
 Catch ex As NullReferenceException 
 End Try 
 End Sub 
 
 Private Sub Form1_Load（ByVal sender As System.Object，ByVal e As System.EventArgs）
处理MyBase.Load 
 loadCompanyList（）
 E nd Sub 
 
结束类
  

数据库类

当我尝试将 getCompanyList（）放在一个类中，然后创建一个引用 Form（）它似乎没有从表中返回任何值到 MyForm.BindingSource1.Datasource 意味着我的datagridview显示不数据。

  ..... 
 Private Sub getCompanyList（）
尝试
 
将myForm作为新的Form（）
 
 connect_Transaction_Database（）
 objDataAdapter.SelectCommand =新建的SqlCommand（）
 objDataAdapter.SelectCommand.Connection = connectString 
 objDataAdapter。 SelectCommand.CommandText =sp_GetCompanyList
 objDataAdapter.SelectCommand.CommandType = CommandType.StoredProcedure 
 
 Dim commandBuilder作为新的SqlCommandBuilder（Me.objDataAdapter）
 
 Dim table As New DataTable（）
 ta ble.Locale = System.Globalization.CultureInfo.InvariantCulture 
 Me.objDataAdapter.Fill（table）
 ** MyForm.bindingSource1.DataSource = table ** 
 
 Catch ex As DataException 
 MsgBox（ex.Message）
 Catch ex As NullReferenceException 
 MsgBox（ex.Message）
结束尝试
 
 disconnect_Transaction_Database（）
 
 End Sub 
  

解决方案

我建议你将GetCompanyList方法转换为返回由数据适配器填充的DataTable的函数。没有什么真正的原因，这个Sub应该具有对表单的依赖，而是形式的方法可以称之为获取DataTable然后执行绑定。

 公共函数GetCompanyList（）As DataTable 
 ... 
 ... 
 Dim table As New DataTable（）
 table.Locale = System.Globalization .CultureInfo.InvariantCulture 
 Me.objDataAdapter.Fill（table）
返回表
 ... 
 ... 
  

I have a bit of code which loads data from a stored procedure in MS SQL Server and then loads the data to a datagridview, which works fine. What i want is for the code that connects / loads the data to sit in my Database Class and then everything associated with the datagridview to be stored in my Form but i am having problems passing the contents of the bindingsource over to the Form from the Database Class.

Form1

Public Class Form1

Dim myDatabaseObj As New Class1()
Dim bindingSource1 As New BindingSource()
Dim connectString As New SqlConnection
Dim objDataAdapter As New SqlDataAdapter
Dim table As New DataTable()
Dim tabletest As New DataTable()

Private Sub loadCompanyList()
    Try
        Me.dgv_CompanyList.DataSource = Me.bindingSource1
        getCompanyList()

    Catch ex As NullReferenceException
    End Try
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)       
Handles MyBase.Load
    loadCompanyList()
End Sub

End Class

Database Class

When I try place the getCompanyList() in a class and then create a new object that references the Form() it does not seem to return any value from the table to the MyForm.BindingSource1.Datasource meaning my datagridview displays not data.

.....
Private Sub getCompanyList()
    Try

        Dim myForm as new Form()

        connect_Transaction_Database()
        objDataAdapter.SelectCommand = New SqlCommand()
        objDataAdapter.SelectCommand.Connection = connectString
        objDataAdapter.SelectCommand.CommandText = "sp_GetCompanyList"
        objDataAdapter.SelectCommand.CommandType = CommandType.StoredProcedure

        Dim commandBuilder As New SqlCommandBuilder(Me.objDataAdapter)

        Dim table As New DataTable()
        table.Locale = System.Globalization.CultureInfo.InvariantCulture
        Me.objDataAdapter.Fill(table)
        **MyForm.bindingSource1.DataSource = table**

    Catch ex As DataException
        MsgBox(ex.Message)
    Catch ex As NullReferenceException
        MsgBox(ex.Message)
    End Try

    disconnect_Transaction_Database()

End Sub

解决方案

I would suggest you make the GetCompanyList method into a Function that returns the DataTable filled by the data adapter. There's no real reason this Sub should have a dependency on the form, instead a method in the form could call this to get the DataTable and then perform the binding.

Public Function GetCompanyList() As DataTable
...
...
   Dim table As New DataTable()
   table.Locale = System.Globalization.CultureInfo.InvariantCulture
   Me.objDataAdapter.Fill(table)
   Return table
...
...

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