Private Sub TextBox23_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox23.TextChanged PictureBox2.Image = Nothing If TextBox23.Text <> Nothing Then If Not ((TextBox23.Text)) Then MessageBox.Show("找不到文件;" & TextBox23.Text) TextBox23.Text = "d:\数据库\空白文件.jpg" End If PictureBox2.Image = Image.FromFile(TextBox23.Text) Else PictureBox2.Image = Nothing End If End Sub