问题
My chart loads data from a DataGridView.
I want to automatically update my chart with new data if new values are inserted into the DataGridView.
My chart is bound to table1 and table2 in my DataGridView which gets values from a DataTable. Here is a small portion of the code:
Dim myData As New DataTable
wcAdapter.SelectCommand = wcCommand
wcAdapter.Fill(myData)
-
Chart1.DataSource = myData
Chart1.Series("Series1").ValueMemberX = "table1"
Chart1.Series("Series1").ValueMembersY = "table2"
Here is the complete code:
Try
wcconn.Open()
Dim wcCommand As New MySqlCommand()
''telesales name
' Dim wcQuery = "SELECT ID, Telesales, SUBSTRING(lastupdatedate, 1, 10) as 'Day', SUBSTRING(lastupdatetime FROM -9 FOR 6) as 'Time' FROM ratingout where Telesales='" & cbTelesales.Text & "' and lastupdatedate= '" & newDate & "' and lastupdatedate is not null and lastupdatetime is not null ORDER BY lastupdatetime ;"
' wcCommand.Connection = wcconn
' wcCommand.CommandText = wcQuery
Dim newDate As String
newDate = dateWorkCheck.Text
newDate = newDate.Replace("/", "-")
Dim y, m, d As String
y = newDate.Substring(6, 4)
m = newDate.Substring(3, 2)
d = newDate.Substring(0, 2)
newDate = y & "-" & m & "-" & d
Dim wcQuery = "SELECT ID, Telesales, lastupdatedate as 'Day', SUBSTRING(lastupdatetime FROM -8 FOR 2) as 'Time' FROM ratingout where Telesales='" & cbTelesales.Text & "' and lastupdatedate= '" & newDate & "' and lastupdatedate is not null and lastupdatetime is not null ORDER BY lastupdatetime ;"
wcCommand.Connection = wcconn
wcCommand.CommandText = wcQuery
Dim wcData As New DataTable
wcAdapter.SelectCommand = wcCommand
wcAdapter.Fill(wcData)
Dim i = 0
If wcData.Rows.Count = 0 Then
wcAdapter.Dispose()
Try
Dim wQuery = "SELECT ID, Telesales, lastupdatedate as 'Day', SUBSTRING(lastupdatetime FROM -8 FOR 2) as 'Time' FROM ratingout where Telesales='" & cbTelesales.Text & "' and lastupdatedate= '" & dateWorkCheck.Text & "' and lastupdatedate is not null and lastupdatetime is not null ORDER BY lastupdatetime ;"
wcCommand.Connection = wcconn
wcCommand.CommandText = wQuery
Dim wData As New DataTable
wcAdapter.SelectCommand = wcCommand
wcAdapter.Fill(wData)
wData.Columns.Add("tt")
wData.Columns.Add("num")
wcData.Columns.Add("tt")
wcData.Columns.Add("num")
'dgvWorkCheck.AutoSizeRowsMode = DataGridViewAutoSizeRowMode.AllCells
Dim dr As DataRow
For Each dr In wData.Rows
If lastV Is Nothing OrElse Not ColumnEqual(lastV, dr("Time")) Then
''check if first value is nothing
If lastV = Nothing Then
lastV = "00"
l = "0"
Else
dr("tt") = lastV
dr("num") = l
'wcData.Tables("ratingout").Rows(I)("ID") = dr("ID")
End If
ListBox1.Items.Add(lastV & " <--> " & l)
lastV = dr("Time")
l = 1
ElseIf lastV Is Nothing OrElse ColumnEqual(lastV, dr("Time")) Then
l += 1
'Dim series1 As New Series()
'series1.Points.Add(l)
End If
For I = I To wData.Rows.Count
If I <> wData.Rows.Count Then
I += 1
If i = wData.Rows.Count Then
dr("tt") = lastV
dr("num") = l
ListBox1.BeginUpdate()
ListBox1.Items.Add(dr("Telesales") & " between[" & lastV & " and 17:00, ] <--> " & l & "[ records ]")
ListBox1.EndUpdate()
End If
GoTo n
Else
MsgBox("last data")
End If
Next
n:
Next
txtRec.Text = wData.Rows.Count
dgvWorkCheck.DataSource = wData
''chart
Dim ChartArea2 As ChartArea = New ChartArea()
Dim Legend2 As Legend = New Legend()
Dim Series2 As Series = New Series()
Dim Chart2 = New Chart()
Me.Controls.Add(Chart2)
ChartArea2.AxisX.LabelStyle.Angle = -90
ChartArea2.AxisX.LabelStyle.Interval = 1
ChartArea2.AxisY.LabelStyle.Angle = -90
ChartArea2.AxisY.LabelStyle.Interval = 5
ChartArea2.Name = "ChartArea2"
Chart2.ChartAreas.Add(ChartArea2)
Legend2.Name = "Legend2"
Chart2.Legends.Add(Legend2)
Chart2.Location = New System.Drawing.Point(12, 113)
Chart2.Name = "Chart2"
Series2.ChartArea = "ChartArea2"
Series2.Legend = "Legend2"
Series2.Name = "Series2"
Chart2.Series.Add(Series2)
Chart2.Size = New System.Drawing.Size(1145, 604)
Chart2.TabIndex = 0
Chart2.Text = "Chart2"
Chart2.Series("Series2").XValueMember = "tt"
Chart2.Series("Series2").YValueMembers = "num"
Chart2.DataSource = dgvWorkCheck.DataSource
Chart2.DataBind()
Catch ex As Exception
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
Exit Try
回答1:
since the new data is inserted into a database, you will only need to rebind the gridview to it's source in order to display the new incoming data.
You should isolate the code that binds data to your chart in a function and have it called every time a new field gets inserted:
Function FillChartWithData()
Dim myData As New DataTable
wcAdapter.SelectCommand = wcCommand
wcAdapter.Fill(myData)
...
Chart1.Series("Series1").ValueMemberX = "table1"
Chart1.Series("Series1").ValueMembersY = "table2"
End Function
EDIT
I looked at your coded and it seems you're missing the part responsible for inserting new data inside the 'ratingout' table. You should create a function that allows you to insert new data, something along the line of:
Dim insertRating = "INSERT INTO ratingout VALUES (@NewTeleSalesName, @NewDate);"
Dim insertCmd As New MySqlCommand(insertRating, wcconn)
insertCmd.Parameters.Add("@NewTeleSalesName", MySqlDbType.VarChar, 255, "teleSalesName")
insertCmd.Parameters.Add("@NewDate", MySqlDbType.Datetime, 8, New DateTime(2010, 8, 5))
insertCmd.ExecuteNonQuery()
回答2:
In order to update my chart bargraph named CashChart (which was databound to a BindingSource) I had to do the following:
To clear the chart information,
Clear the bounding source information
And then re-assign the bounding source information: for example:
CashChart.Series(0).Points.Clear() CashChart.DataSource = "" CashChart.DataSource = ESTADOINSTANTANEOBindingSource
Before, only my DataTable was updating, but after these commands, I was able to get the bargraph to update with new values in the table.
来源：https://stackoverflow.com/questions/3317718/automatic-chart-update-with-new-data-entry