Como proceder para limpar um Chart já existente para apor novos dados?

Question

Boa noite a todos!

A dificuldade agora é outra, pois preciso limpar um gráfico já existente e com dados para colocar novos dados de acordo com a seleção do cliente? A quem puder ajudar-me agradeço!

Att.

---

Dilson J. Hasselmann Desenvolvedor VB.NET

Answer 1

Dilson,

Vc está utilizando o Microsoft Chart Controls? Em caso afirmativo, o processo é bem simples, apenas associar os novos dados ao DataSource do controle e acionar o método DataBind:

exemploChart.DataSource = dados;
exemploChart.DataBind();

Caso tenha interesse em conhecer mais sobre o Microsoft Chart Controls, escrevi há algum tempo um artigo para a revista .NET Magazine em que abordo em maiores detalhes o uso deste framework:

http://www.devmedia.com.br/microsoft-chart-controls-revista-net-magazine-94/23664

Answer 2

Boa tarde!

Sim estou utilizando o Chart Controls no VB.NET 2012 o fragmento do código segue abaixo:

Private Sub Monta_Grafico()

      Dim tblFields As String = "SELECT * from tbRelGrafVenda Order By CodPizzaFormula, Dia"
 
      '~~> Connecting to Data base and storing the data in a dataset
      Dim oCmd As New OleDbCommand(tblFields, gCN)
      Dim oData As New OleDbDataAdapter(tblFields, gCN)

      Dim ds As New DataSet

      If gCN.State = ConnectionState.Open Then gCN.Close()
      gCN.Open()

      oData.Fill(ds, "tbRelGrafVenda")
      gCN.Close()

      '''''''''''''''''''''''''''''
      '~~> SET DATA SOURCE <~~'
      '''''''''''''''''''''''''''''
      Chart1.DataSource = ds.Tables("tbRelGrafVenda")

      ''''''''''''''''''''''''''''''''
      '~~> WORKING WITH CHARTAREA <~~'
      ''''''''''''''''''''''''''''''''
      Dim CArea As ChartArea = Chart1.ChartAreas(0)

      CArea.BackColor = Color.DarkOliveGreen  '~~> Changing the Back Color of the Chart Area 
      CArea.BackGradientStyle = GradientStyle.TopBottom
      CArea.ShadowColor = Color.Red           '~~> Changing the Shadow Color of the Chart Area 
      CArea.ShadowColor = Color.Red           '~~> Changing the Shadow Color of the Chart Area 
      CArea.Area3DStyle.Enable3D = False      '~~> Changing the Chart Style Not 3D 

      '~~> Formatting X Axis
      CArea.AxisX.MajorGrid.Enabled = False   '~~> Removed the X axis major grids
      CArea.AxisX.LabelStyle.Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Italic) '~~> Setting Font, Font Size and Italicizing
      CArea.AxisX.Interval = 1
      CArea.AxisX.Maximum = 31
      CArea.AxisX.Minimum = 1

      '~~> Formatting Y Axis
      CArea.AxisY.MinorGrid.Enabled = False   '~~> Removed the Y axis major grids
      CArea.AxisY.LabelStyle.Format = "000"   '~~> Formatting Y axis to display values in %age
      CArea.AxisY.Interval = 2                '~~> Formatting Y axis Interval to 20%

      ''''''''''''''''''''''''''''
      '~~> WORKING WITH TITLE <~~'
      ''''''''''''''''''''''''''''
      '~~> Adding a Title
      Dim T As Title = Chart1.Titles.Add("Relatório de Vendas - MES")

      '~~> Formatting the Title
      With T
         .ForeColor = Color.Black            '~~> Changing the Fore Color of the Title 
         .BackColor = Color.White            '~~> Changing the Back Color of the Title 
         '~~> Setting Font, Font Size and Bold/Italicizing
         .Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
         .Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Underline)
         .BorderColor = Color.Black                   '~~> Changing the Border Color of the Title 
         .BorderDashStyle = ChartDashStyle.NotSet  '~~> Changing the Border Dash Style of the Title 
      End With

      '''''''''''''''''''''''''''''
      '~~> WORKING WITH SERIES <~~'
      '''''''''''''''''''''''''''''
      '~~> Assigning values to X and Y Axis

      'Tamanho Grande
      Chart1.Series(0).LabelFormat = "00"
      Chart1.Series(0).XValueMember = "Dia"
      Chart1.Series(0).YValueMembers = "TotQtd"
      Chart1.Series(0).Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      Chart1.Series(0).YValueType = ChartValueType.Double
      Chart1.Series(0).IsValueShownAsLabel = False

      'Tamanho Médio
      Chart1.Series(1).LabelFormat = "00"
      Chart1.Series(1).XValueMember = "Dia"
      Chart1.Series(1).YValueMembers = "TotQtd1"
      Chart1.Series(1).Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      Chart1.Series(1).YValueType = ChartValueType.Double
      Chart1.Series(1).IsValueShownAsLabel = False

      'Tamanho Broto
      Chart1.Series(2).LabelFormat = "00"
      Chart1.Series(2).XValueMember = "Dia"
      Chart1.Series(2).YValueMembers = "TotQtd2"
      Chart1.Series(2).Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      Chart1.Series(2).YValueType = ChartValueType.Double
      Chart1.Series(2).IsValueShownAsLabel = False

      '''''''''''''''''''''''''''''
      '~~> WORKING WITH LEGEND <~~'
      '''''''''''''''''''''''''''''
      Dim LG As Legend = Chart1.Legends(0)
      '~~> Changing the Back Color of the Legend 
      LG.BackColor = Color.Wheat
      '~~> Changing the Fore Color of the Legend
      LG.ForeColor = Color.DarkSlateBlue
      '~~> Setting Font, Font Size and Bold
      LG.Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      '~~> Assigning a title for the legend
      LG.Title = "Legenda"

      '~~> Setting the location for the chart
      Chart1.Size = New System.Drawing.Size(1232, 594)
      Chart1.Location = New Point(12, 68)

   End Sub

Aqui chamo a rotina para montar a Tabela classificada!

Private Sub dtpMesAno_ValueChanged(sender As Object, e As EventArgs) Handles dtpMesAno.ValueChanged

      Call Classificar_Dados()

   End Sub

E aqui chamo o gráfico proprieamente dito!

         gSQL = Nothing
         gCMD.Dispose()
         gDtR.Close()

         Call Monta_Grafico()

      Catch ex As Exception

Se puder ajudar-me de como usar a sua dica em seu post agradeço!A

Att.

---

Dilson J. Hasselmann Desenvolvedor VB.NET

Answer 3

Altere o método Monta_Grafico para que fique da seguinte maneira (as mudanças envolvem a atribuição do valor à propriedade DataSource e chamar o DataBind ao final):

Private Sub Monta_Grafico()

      Dim tblFields As String = "SELECT * from tbRelGrafVenda Order By CodPizzaFormula, Dia"
 
      '~~> Connecting to Data base and storing the data in a dataset
      Dim oCmd As New OleDbCommand(tblFields, gCN)
      Dim oData As New OleDbDataAdapter(tblFields, gCN)

      Dim ds As New DataSet

      If gCN.State = ConnectionState.Open Then gCN.Close()
      gCN.Open()

      oData.Fill(ds, "tbRelGrafVenda")
      gCN.Close()


      ''''''''''''''''''''''''''''''''
      '~~> WORKING WITH CHARTAREA <~~'
      ''''''''''''''''''''''''''''''''
      Dim CArea As ChartArea = Chart1.ChartAreas(0)

      CArea.BackColor = Color.DarkOliveGreen  '~~> Changing the Back Color of the Chart Area 
      CArea.BackGradientStyle = GradientStyle.TopBottom
      CArea.ShadowColor = Color.Red           '~~> Changing the Shadow Color of the Chart Area 
      CArea.ShadowColor = Color.Red           '~~> Changing the Shadow Color of the Chart Area 
      CArea.Area3DStyle.Enable3D = False      '~~> Changing the Chart Style Not 3D 

      '~~> Formatting X Axis
      CArea.AxisX.MajorGrid.Enabled = False   '~~> Removed the X axis major grids
      CArea.AxisX.LabelStyle.Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Italic) '~~> Setting Font, Font Size and Italicizing
      CArea.AxisX.Interval = 1
      CArea.AxisX.Maximum = 31
      CArea.AxisX.Minimum = 1

      '~~> Formatting Y Axis
      CArea.AxisY.MinorGrid.Enabled = False   '~~> Removed the Y axis major grids
      CArea.AxisY.LabelStyle.Format = "000"   '~~> Formatting Y axis to display values in %age
      CArea.AxisY.Interval = 2                '~~> Formatting Y axis Interval to 20%

      ''''''''''''''''''''''''''''
      '~~> WORKING WITH TITLE <~~'
      ''''''''''''''''''''''''''''
      '~~> Adding a Title
      Dim T As Title = Chart1.Titles.Add("Relatório de Vendas - MES")

      '~~> Formatting the Title
      With T
         .ForeColor = Color.Black            '~~> Changing the Fore Color of the Title 
         .BackColor = Color.White            '~~> Changing the Back Color of the Title 
         '~~> Setting Font, Font Size and Bold/Italicizing
         .Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
         .Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Underline)
         .BorderColor = Color.Black                   '~~> Changing the Border Color of the Title 
         .BorderDashStyle = ChartDashStyle.NotSet  '~~> Changing the Border Dash Style of the Title 
      End With

      '''''''''''''''''''''''''''''
      '~~> WORKING WITH SERIES <~~'
      '''''''''''''''''''''''''''''
      '~~> Assigning values to X and Y Axis

      'Tamanho Grande
      Chart1.Series(0).LabelFormat = "00"
      Chart1.Series(0).XValueMember = "Dia"
      Chart1.Series(0).YValueMembers = "TotQtd"
      Chart1.Series(0).Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      Chart1.Series(0).YValueType = ChartValueType.Double
      Chart1.Series(0).IsValueShownAsLabel = False

      'Tamanho Médio
      Chart1.Series(1).LabelFormat = "00"
      Chart1.Series(1).XValueMember = "Dia"
      Chart1.Series(1).YValueMembers = "TotQtd1"
      Chart1.Series(1).Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      Chart1.Series(1).YValueType = ChartValueType.Double
      Chart1.Series(1).IsValueShownAsLabel = False

      'Tamanho Broto
      Chart1.Series(2).LabelFormat = "00"
      Chart1.Series(2).XValueMember = "Dia"
      Chart1.Series(2).YValueMembers = "TotQtd2"
      Chart1.Series(2).Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      Chart1.Series(2).YValueType = ChartValueType.Double
      Chart1.Series(2).IsValueShownAsLabel = False

      '''''''''''''''''''''''''''''
      '~~> WORKING WITH LEGEND <~~'
      '''''''''''''''''''''''''''''
      Dim LG As Legend = Chart1.Legends(0)
      '~~> Changing the Back Color of the Legend 
      LG.BackColor = Color.Wheat
      '~~> Changing the Fore Color of the Legend
      LG.ForeColor = Color.DarkSlateBlue
      '~~> Setting Font, Font Size and Bold
      LG.Font = New System.Drawing.Font("Times New Roman", 11.0F, System.Drawing.FontStyle.Bold)
      '~~> Assigning a title for the legend
      LG.Title = "Legenda"

      '~~> Setting the location for the chart
      Chart1.Size = New System.Drawing.Size(1232, 594)
      Chart1.Location = New Point(12, 68)

      '''''''''''''''''''''''''''''
      '~~> SET DATA SOURCE <~~' Movido para este ponto
      '''''''''''''''''''''''''''''
      Chart1.DataSource = ds.Tables("tbRelGrafVenda")
      Chart1.DataBind

   End Sub