Visual Basic和SQL图片框控件

Question

将图片框叠加到图片上，如下所示。 Click for Form Layout

当表单加载时，如果学生出席班级，那么图片框会变成绿色的勾号。如果学生不参加课堂，图片框就会变成空白。

使用SQL我可以查询数据库以返回特定学生所参加的所有类。 这些类存储在一个数组中StudentClass（n）

时间表上有50个类存储在数组AttendsClass（n）中。所有的默认值都是False。 如果学生出席某个班级，则该数组中的特定出席班成为True。

加载表单后，用户可以单击一个图片框来选择该类，并且数组中的相应attends类变为true。 最后，用户保存表格，将类插回到数据库中。

我的问题是在Sub Form4_Load最后，我现在不得不重复相同的代码块50次。这只是检查学生是否参加了课堂，然后将图片框=设置为GUI（_new.jpg）上的图片。

enter code here 
If AttendsClass(1) = True Then 
     PictureBox1.Image = My.Resources._new 
    End If 
    If AttendsClass(2) = True Then 
     PictureBox2.Image = My.Resources._new 
    End If 
    If AttendsClass(3) = True Then 
     PictureBox3.Image = My.Resources._new 
    End If 
    If AttendsClass(4) = True Then 
     PictureBox4.Image = My.Resources._new 
    End If 

是否有可能把它放到一个循环中以缩短我的代码。代码确实有效，但是它的速度很慢且很长，所以任何改进都会有所帮助。 非常感谢亚历克斯·柯里 一个级计算学生 全码：

enter code here 
Imports System.Data.OleDb 
Public Class Form4 
Public con As New OleDbConnection 
Public ds As New DataSet 
Public da As OleDbDataAdapter 
Public cb As OleDbCommandBuilder 
Public constring As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source =" & Application.StartupPath & "\wma.accdb" 
Public AttendsClass(50) As Boolean 
Public StdID As Integer = Form2.DataGridView1.SelectedRows(0).Cells("StudentID").Value 
Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
    Dim Forename As String = Form2.DataGridView1.SelectedRows(0).Cells("Forename").Value 
    Dim Surname As String = Form2.DataGridView1.SelectedRows(0).Cells("Surname").Value 
    Student.Text = "Student: " & Forename & " " & Surname 
    If Not con.State = ConnectionState.Open Then 
     con.ConnectionString = constring 
     con.Open() 
    End If 
    da = New OleDbDataAdapter("SELECT * FROM StudentClass WHERE StudentId = " & StdID, con) 
    da.Fill(ds, "Class") 
    Dim Maxrow As Integer = ds.Tables("Class").Rows.Count 
    Dim StudentClass(Maxrow) As Integer 
    For n = 1 To 50 
     AttendsClass(n) = False 
    Next 

    For n = 1 To Maxrow 
     StudentClass(n) = ds.Tables("Class").Rows(n - 1).Item(1) 
     For a = 0 To 50 
      If StudentClass(n) = a Then 
       AttendsClass(a) = True 
      End If 
     Next 
    Next 

    If AttendsClass(1) = True Then 
     PictureBox1.Image = My.Resources._new 
    End If 
    If AttendsClass(2) = True Then 
     PictureBox2.Image = My.Resources._new 
    End If 
    If AttendsClass(3) = True Then 
     PictureBox3.Image = My.Resources._new 
    End If 
    If AttendsClass(4) = True Then 
     PictureBox4.Image = My.Resources._new 
    End If 

End Sub 

Private Sub PictureBox1_Click(sender As System.Object, e As System.EventArgs) Handles PictureBox1.Click 
    If PictureBox1.Image Is Nothing Then 
     PictureBox1.Image = My.Resources._new 
     AttendsClass(1) = True 
    Else 
     PictureBox1.Image = Nothing 
     AttendsClass(1) = False 
    End If 
End Sub 

Private Sub PictureBox2_Click(sender As System.Object, e As System.EventArgs) Handles PictureBox2.Click 
    If PictureBox2.Image Is Nothing Then 
     PictureBox2.Image = My.Resources._new 
     AttendsClass(2) = True 
    Else 
     PictureBox2.Image = Nothing 
     AttendsClass(2) = False 
    End If 
End Sub 

Private Sub PictureBox4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PictureBox4.Click 
    If PictureBox4.Image Is Nothing Then 
     PictureBox4.Image = My.Resources._new 
     AttendsClass(4) = True 
    Else 
     PictureBox4.Image = Nothing 
     AttendsClass(4) = False 
    End If 
End Sub 

Private Sub PictureBox3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PictureBox3.Click 
    If PictureBox3.Image Is Nothing Then 
     PictureBox3.Image = My.Resources._new 
     AttendsClass(3) = True 
    Else 
     PictureBox3.Image = Nothing 
     AttendsClass(3) = False 
    End If 
End Sub 

Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click 
    If Not con.State = ConnectionState.Open Then 
     con.ConnectionString = constring 
     con.Open() 
    End If 
    Dim cmd As New OleDb.OleDbCommand 
    cmd.Connection = con 

    'Deletes Existing Records To Be rewritten' 
    cmd.CommandText = "DELETE * FROM StudentClass WHERE StudentID=" & StdID 
    cmd.ExecuteNonQuery() 

    For n = 1 To 50 
     If AttendsClass(n) = True Then 
      cmd.CommandText = "INSERT INTO StudentClass (StudentID, ClassID) VALUES (" & StdID & "," & n & ")" 
      cmd.ExecuteNonQuery() 
     End If 
    Next 
    Me.Dispose() 
    MsgBox("Updated Successfully", MsgBoxStyle.Information, "WMA") 
    con.Close() 
End Sub 
End Class 

Answer 1

工作例如：

Private Sub PictureBox1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _ 
Handles PictureBox1.Click, ...., PictureBox50.Click 
    Dim pic As PictureBox = CType(Controls(CType(sender, PictureBox).Name), PictureBox) 
    'now you have clicked picturebox 
    'you can change image by pic.Image = ... 
    'if you want picturebox index, use line below: 
    Dim picidx As Integer = CInt(CType(sender, PictureBox).Name.Replace("PictureBox", "")) 

End Sub 

VB2010Ex。