VB.NET WinForms中DataGridView二次点击按钮不显示行求助

方案1：强制触发控件刷新与布局 #

有时候DataGridView更新数据源后，不会自动触发重绘和布局，导致数据行无法显示。可以在设置完DataSource后，手动调用刷新和布局方法：

Private Sub btnSettings_Click(sender As Object, e As EventArgs) Handles btnSettings.Click
    Dim t As DataTable

    Me.Cursor = Cursors.WaitCursor
    dgvSettings.Visible = False
    btnSettings.Enabled = False

    ' Get the settings and show them in the grid.
    dgvSettings.DataSource = Nothing
    t = GetSettings()
    dgvSettings.DataSource = t
    
    ' 强制刷新并重置布局
    dgvSettings.Refresh()
    dgvSettings.PerformLayout()

    btnSettings.Enabled = True
    dgvSettings.Visible = True
    Me.Cursor = Cursors.Default
End Sub

方案2：通过BindingSource作为数据中间层 #

直接绑定DataTable偶尔会出现绑定不稳定的情况，用BindingSource作为数据源容器，能更可靠地处理数据更新：

首先在窗体级别声明BindingSource：

Private settingsBindingSource As New BindingSource()

然后修改点击事件代码：

Private Sub btnSettings_Click(sender As Object, e As EventArgs) Handles btnSettings.Click
    Dim t As DataTable

    Me.Cursor = Cursors.WaitCursor
    dgvSettings.Visible = False
    btnSettings.Enabled = False

    ' Get the settings and show them in the grid.
    settingsBindingSource.DataSource = Nothing
    t = GetSettings()
    settingsBindingSource.DataSource = t
    dgvSettings.DataSource = settingsBindingSource

    btnSettings.Enabled = True
    dgvSettings.Visible = True
    Me.Cursor = Cursors.Default
End Sub

方案3：确保每次获取全新的DataTable实例 #

如果GetSettings返回的是同一个DataTable实例（比如内部缓存了对象），重复绑定可能导致控件识别不到数据变化。可以在调用时复制一个新的DataTable：

Private Sub btnSettings_Click(sender As Object, e As EventArgs) Handles btnSettings.Click
    Dim t As DataTable

    Me.Cursor = Cursors.WaitCursor
    dgvSettings.Visible = False
    btnSettings.Enabled = False

    ' Get the settings and show them in the grid.
    dgvSettings.DataSource = Nothing
    ' 复制DataTable获取全新实例
    t = GetSettings().Copy()
    dgvSettings.DataSource = t

    btnSettings.Enabled = True
    dgvSettings.Visible = True
    Me.Cursor = Cursors.Default
End Sub

以上三种方案都能解决你遇到的“二次点击仅显示表头，排序后才显示数据”的问题，优先尝试方案2，BindingSource是WinForms中推荐的数据绑定方式，稳定性更高。

内容的提问来源于stack exchange，提问作者LGS