VB.NET中DataGridViewTheme类致DataGridView2行高与DataGridView1不一致问题排查

我尝试编写DataGridViewTheme类统一设置DataGridView的主题样式，但使用该类配置的DataGridView2，其行高与直接配置的DataGridView1不一致，尽管两者的设置代码完全相同。相关代码及解决方案如下：

原代码展示 #

Form1代码 #

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        DataGridView1.AllowUserToResizeRows = False
        DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
        DataGridView1.BorderStyle = BorderStyle.None
        DataGridView1.CellBorderStyle = DataGridViewCellBorderStyle.None
        DataGridView1.ColumnHeadersBorderStyle = DataGridViewHeaderBorderStyle.None
        DataGridView1.ColumnHeadersDefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft
        DataGridView1.ColumnHeadersDefaultCellStyle.Font = New Font("Segoe UI Semibold", 10.0F, System.Drawing.FontStyle.Bold)
        DataGridView1.ColumnHeadersDefaultCellStyle.WrapMode = DataGridViewTriState.True
        DataGridView1.ColumnHeadersHeight = 40
        DataGridView1.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing
        DataGridView1.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft
        DataGridView1.DefaultCellStyle.WrapMode = DataGridViewTriState.False
        DataGridView1.DefaultCellStyle.Font = New Font("Segoe UI", 10.0F)
        DataGridView1.EnableHeadersVisualStyles = False
        DataGridView1.RowHeadersVisible = False
        DataGridView1.RowHeadersWidth = 40
        DataGridView1.RowHeadersWidthSizeMode = DataGridViewRowHeadersWidthSizeMode.DisableResizing
        DataGridView1.RowTemplate.Height = 40
        DataGridView1.RowTemplate.Resizable = DataGridViewTriState.False
        DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
        For i As Integer = 0 To 3
            DataGridView1.Rows.Add(New Object() {"Column 1", "Column 2", "Column 3"})
        Next i
        'set theme
        DataGridView1.AlternatingRowsDefaultCellStyle.BackColor = Color.FromArgb(210, 232, 254)
        DataGridView1.AlternatingRowsDefaultCellStyle.ForeColor = Color.Black
        DataGridView1.AlternatingRowsDefaultCellStyle.SelectionBackColor = Color.LightSkyBlue
        DataGridView1.AlternatingRowsDefaultCellStyle.SelectionForeColor = Color.Black
        DataGridView1.BackgroundColor = Color.FromArgb(248, 251, 254)
        DataGridView1.ColumnHeadersDefaultCellStyle.BackColor = Color.FromArgb(30, 144, 254)
        DataGridView1.ColumnHeadersDefaultCellStyle.ForeColor = Color.White
        DataGridView1.ColumnHeadersDefaultCellStyle.SelectionBackColor = Color.FromArgb(30, 144, 254)
        DataGridView1.ColumnHeadersDefaultCellStyle.SelectionForeColor = Color.White
        DataGridView1.DefaultCellStyle.BackColor = Color.FromArgb(248, 251, 254)
        DataGridView1.DefaultCellStyle.ForeColor = Color.Black
        DataGridView1.DefaultCellStyle.SelectionBackColor = Color.LightSkyBlue
        DataGridView1.DefaultCellStyle.SelectionForeColor = Color.Black
        For i As Integer = 0 To 3
            DataGridView2.Rows.Add(New Object() {"Column 1", "Column 2", "Column 3"})
        Next i
        Dim lightTheme As New DataGridViewTheme(DataGridView2, DataGridViewTheme.Theme.Light)
    End Sub
End Class

DataGridViewTheme类代码 #

Public Class DataGridViewTheme
    Public Enum Theme
        Light
    End Enum
    Public Sub New(ByVal dgv As DataGridView, ByVal Theme As Theme)
        dgv.AllowUserToResizeRows = False
        dgv.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill
        dgv.BorderStyle = BorderStyle.None
        dgv.CellBorderStyle = DataGridViewCellBorderStyle.None
        dgv.ColumnHeadersBorderStyle = DataGridViewHeaderBorderStyle.None
        dgv.ColumnHeadersDefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft
        dgv.ColumnHeadersDefaultCellStyle.Font = New Font("Segoe UI Semibold", 10.0F, System.Drawing.FontStyle.Bold)
        dgv.ColumnHeadersDefaultCellStyle.WrapMode = DataGridViewTriState.True
        dgv.ColumnHeadersHeight = 40
        dgv.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing
        dgv.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft
        dgv.DefaultCellStyle.WrapMode = DataGridViewTriState.False
        dgv.DefaultCellStyle.Font = New Font("Segoe UI", 10.0F)
        dgv.EnableHeadersVisualStyles = False
        dgv.RowHeadersVisible = False
        dgv.RowHeadersWidth = 40
        dgv.RowHeadersWidthSizeMode = DataGridViewRowHeadersWidthSizeMode.DisableResizing
        dgv.RowTemplate.Height = 40
        dgv.RowTemplate.Resizable = DataGridViewTriState.False
        dgv.SelectionMode = DataGridViewSelectionMode.FullRowSelect

        Select Case Theme
            Case DataGridViewTheme.Theme.Light
                Light(dgv)
            Case Else
        End Select
    End Sub
    Private Sub Light(ByVal dgv As DataGridView)
        dgv.AlternatingRowsDefaultCellStyle.BackColor = Color.FromArgb(210, 232, 254)
        dgv.AlternatingRowsDefaultCellStyle.ForeColor = Color.Black
        dgv.AlternatingRowsDefaultCellStyle.SelectionBackColor = Color.LightSkyBlue
        dgv.AlternatingRowsDefaultCellStyle.SelectionForeColor = Color.Black
        dgv.BackgroundColor = Color.FromArgb(248, 251, 254)
        dgv.ColumnHeadersDefaultCellStyle.BackColor = Color.FromArgb(30, 144, 254)
        dgv.ColumnHeadersDefaultCellStyle.ForeColor = Color.White
        dgv.ColumnHeadersDefaultCellStyle.SelectionBackColor = Color.FromArgb(30, 144, 254)
        dgv.ColumnHeadersDefaultCellStyle.SelectionForeColor = Color.White
        dgv.DefaultCellStyle.BackColor = Color.FromArgb(248, 251, 254)
        dgv.DefaultCellStyle.ForeColor = Color.Black
        dgv.DefaultCellStyle.SelectionBackColor = Color.LightSkyBlue
        dgv.DefaultCellStyle.SelectionForeColor = Color.Black
        dgv.Refresh()
    End Sub
End Class

问题原因 #

DataGridView的RowTemplate.Height仅对设置之后添加的行生效。你的代码中：

• DataGridView1是先设置RowTemplate.Height = 40，再添加行，所有行都继承了40的高度
• DataGridView2是先添加行，再通过Theme类设置RowTemplate.Height，已存在的行不会自动更新高度，导致行高不一致

修复方案 #

方案1：调整执行顺序（推荐） #

先初始化DataGridViewTheme，再添加行，让新行直接继承RowTemplate的高度：

' 修改Form1_Load中的DataGridView2代码段
Dim lightTheme As New DataGridViewTheme(DataGridView2, DataGridViewTheme.Theme.Light)
For i As Integer = 0 To 3
    DataGridView2.Rows.Add(New Object() {"Column 1", "Column 2", "Column 3"})
Next i

方案2：兼容已存在的行 #

在Theme类中设置RowTemplate后，遍历所有已存在的行手动设置高度：

' 修改DataGridViewTheme的New方法
Public Sub New(ByVal dgv As DataGridView, ByVal Theme As Theme)
    ' ... 原有设置代码 ...
    dgv.RowTemplate.Height = 40
    dgv.RowTemplate.Resizable = DataGridViewTriState.False
    
    ' 新增：手动更新已存在的行高度
    For Each row As DataGridViewRow In dgv.Rows
        If Not row.IsNewRow Then
            row.Height = 40
        End If
    Next
    
    ' ... 后续主题设置代码 ...
End Sub

内容的提问来源于stack exchange，提问作者dlaksmi