strSQL = "select MAX(ID) from caiming" 最后只返回了一个字段,不知道,你 dr.Item("IMG_url_add") 返回的是哪的东西?
按我的理解应该改成
strSQL = "select * from caiming where ID=(select MAX(ID) from caiming)"
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Randomize() '产生随机数种子 以防止每次生成结果都一样
Dim a(100) As Integer '声明数组存放数据 用来保存随机数结果
Dim max As Integer, min As Integer '声明两个变量存最大值和最小值
min = 1000 : max = 0 '设置初值
If a(i) = max Then max = a(i) '如果当前数值大于最大值的变量就保存
If a(i) = min Then min = a(i) '如果当前数值小于最小值的变量就保存
Next
MsgBox("最大值为" max)
MsgBox("最小值为" min)
End Sub
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim min, max As Integer
min = Proc(a)(0)
max = Proc(a)(1)
Private Function Proc(ByVal a() As Integer)
Dim a_out(a.GetUpperBound(0)), a_m(1) As Integer
System.Array.Copy(a, a_out, a.GetUpperBound(0) + 1)
System.Array.Sort(a_out)
a_m(0) = a_out(0)
a_m(1) = a_out(a_out.GetUpperBound(0))
Return a_m
End Function
End Class
你是不是应该对最大值和最小值赋初值(比如把 r(1) 赋给最大值和最小值)呢?不然最小值默认初始值是'0',后面的判断就不起作用了.你可以加个断点试试,他们的初始值是多少...
Dim con As New OleDb.OleDbConnection(cstring)
Dim sql As String = "select max(字段名) from 表名"
con.Open()
Dim cmd As New OleDb.OleDbCommand(sql, con)
Dim myreader As OleDbDataReader = cmd.ExecuteReader
myreader.Read
TextBox1.Text = myreader(0)
con.Close()
正如一楼所说,你值得是界面中的数据,还是数据库内的数据?请详细描述啊...
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