VB.NET中基于DataTable表达式重命名BaiqiSoft LabelControl导出图片

问题描述 #

在VB.NET中使用BaiqiSoft LabelControl控件导出图片时，控件默认生成序列文件名（如test1.png），需要将这些文件重命名为DataTable中ProductName+Barcode格式的文件名。

现有代码 #

Imports System.IO
Imports BaiqiSoft.LabelControl
Public Class Form1
    Private m_DataTable As DataTable
    Private Sub CreateDataTable()
        If m_DataTable IsNot Nothing Then Return
        m_DataTable = New DataTable
        'Columns
        m_DataTable.Columns.Add("ProductName", GetType(String))
        m_DataTable.Columns.Add("Barcode", GetType(String))
        m_DataTable.Columns.Add("Price", GetType(Single))
        m_DataTable.Columns.Add("LabelNumber", GetType(Integer))
        m_DataTable.Columns.Add("QTY", GetType(Integer))
        m_DataTable.Columns.Add("Filename", GetType(String), "ProductName +','+ Barcode")
        'Rows
        m_DataTable.Rows.Add("Mishi Kobe Niku", "845723054943", 96.0, 2, 1)
        m_DataTable.Rows.Add("Carnarvon Tigers", "246321456231", 61.5, 1, 1)
        m_DataTable.Rows.Add("Ipoh Coffee", "589412354786", 46.0, 3, 1)
        m_DataTable.Rows.Add("Aniseed Syrup", "457125463254", 10.0, 1, 1)
        m_DataTable.Rows.Add("Teatime Chocolate Biscuits", "232145674321", 9.2, 5, 1)
    End Sub
Private Sub Btnexport_Click(sender As Object, e As EventArgs) Handles Btnexport.Click
        Dim theLabel As New LabelPrinting()
        theLabel.LicenseKey = ""
        theLabel.OpenLabel(Application.StartupPath & "\test.blf")
        Dim selectedRows As DataTable = m_DataTable.Clone
        selectedRows.Columns("Filename").Expression = Nothing : selectedRows.Columns("Filename").ReadOnly = False
        For Each row2 As DataGridViewRow In DataGridView1.Rows
            Dim isselect As Boolean = Convert.ToBoolean(row2.Cells("checkboxcolumn").Value)
            If isselect Then
                Dim newRow As DataRow = selectedRows.NewRow()
                newRow("ProductName") = m_DataTable.Rows(row2.Index)("ProductName")
                newRow("Barcode") = m_DataTable.Rows(row2.Index)("Barcode")
                newRow("Price") = m_DataTable.Rows(row2.Index)("Price")
                newRow("LabelNumber") = m_DataTable.Rows(row2.Index)("LabelNumber")
                newRow("QTY") = m_DataTable.Rows(row2.Index)("QTY")
                newRow("Filename") = m_DataTable.Rows(row2.Index)("ProductName") + "," + m_DataTable.Rows(row2.Index)("Barcode") + ".png"
                selectedRows.Rows.Add(newRow)
                theLabel.Label.QuantityColumn = "QTY"
            End If
        Next row2
        theLabel.DataSource = selectedRows
        theLabel.ExportOptions.FileName = "test"
        theLabel.ExportOptions.Path = Application.StartupPath
        theLabel.ExportOptions.Quantity = QuantityOptions.AllRecords
        theLabel.ExportOptions.Format = ImageFormats.Png
        theLabel.ExportOptions.Resolution = 300
        theLabel.ExportImage()
    End Sub
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        CreateDataTable()
        DataGridView1.DataSource = m_DataTable
        Dim CheckedBoxColumn As New DataGridViewCheckBoxColumn
        CheckedBoxColumn.Width = 40
        CheckedBoxColumn.Name = "checkboxcolumn"
        CheckedBoxColumn.HeaderText = "Check"
        DataGridView1.Columns.Insert(0, CheckedBoxColumn)
    End Sub
End Class

当前输出 #

test1.png
test2.png
test3.png
test4.png
test5.png

期望输出 #

Mishi Kobe Niku,845723054943.png
Carnarvon Tigers,246321456231.png
Ipoh Coffee,589412354786.png
Aniseed Syrup,457125463254.png
Teatime Chocolate Biscuits,232145674321.png

实现方案 #

由于控件本身设计为生成序列文件名，只能在导出完成后进行批量重命名。核心逻辑是：导出的文件顺序与selectedRows中的行顺序完全对应，因此可以遍历selectedRows，依次将testN.png重命名为对应行的Filename字段值。

修改后的完整Btnexport_Click方法 #

Private Sub Btnexport_Click(sender As Object, e As EventArgs) Handles Btnexport.Click
    Dim theLabel As New LabelPrinting()
    theLabel.LicenseKey = ""
    theLabel.OpenLabel(Application.StartupPath & "\test.blf")
    Dim selectedRows As DataTable = m_DataTable.Clone
    selectedRows.Columns("Filename").Expression = Nothing : selectedRows.Columns("Filename").ReadOnly = False
    For Each row2 As DataGridViewRow In DataGridView1.Rows
        Dim isselect As Boolean = Convert.ToBoolean(row2.Cells("checkboxcolumn").Value)
        If isselect Then
            Dim newRow As DataRow = selectedRows.NewRow()
            newRow("ProductName") = m_DataTable.Rows(row2.Index)("ProductName")
            newRow("Barcode") = m_DataTable.Rows(row2.Index)("Barcode")
            newRow("Price") = m_DataTable.Rows(row2.Index)("Price")
            newRow("LabelNumber") = m_DataTable.Rows(row2.Index)("LabelNumber")
            newRow("QTY") = m_DataTable.Rows(row2.Index)("QTY")
            newRow("Filename") = m_DataTable.Rows(row2.Index)("ProductName") + "," + m_DataTable.Rows(row2.Index)("Barcode") + ".png"
            selectedRows.Rows.Add(newRow)
            theLabel.Label.QuantityColumn = "QTY"
        End If
    Next row2
    theLabel.DataSource = selectedRows
    theLabel.ExportOptions.FileName = "test"
    theLabel.ExportOptions.Path = Application.StartupPath
    theLabel.ExportOptions.Quantity = QuantityOptions.AllRecords
    theLabel.ExportOptions.Format = ImageFormats.Png
    theLabel.ExportOptions.Resolution = 300
    theLabel.ExportImage()

    ' 新增：导出完成后执行重命名操作
    Dim exportPath As String = theLabel.ExportOptions.Path
    For i As Integer = 0 To selectedRows.Rows.Count - 1
        Dim oldFileName As String = Path.Combine(exportPath, $"test{i+1}.png")
        Dim newFileName As String = Path.Combine(exportPath, selectedRows.Rows(i)("Filename").ToString())
        ' 检查文件是否存在，避免异常
        If File.Exists(oldFileName) Then
            ' 处理重名情况，避免覆盖
            If File.Exists(newFileName) Then
                newFileName = Path.Combine(exportPath, $"{Path.GetFileNameWithoutExtension(newFileName)}_{i+1}{Path.GetExtension(newFileName)}")
            End If
            File.Move(oldFileName, newFileName)
        End If
    Next
End Sub

关键说明 #

• 导出文件的顺序与selectedRows中行的顺序完全一致，通过索引i+1对应test{i+1}.png可保证映射准确。
• 添加了文件存在检查，避免因文件不存在或重名导致的异常；若遇到重名文件，会自动在文件名后添加序号后缀。
• 代码中已手动为selectedRows的Filename字段赋值，无需依赖DataTable表达式，确保文件名格式正确。

内容的提问来源于stack exchange，提问作者dlaksmi