Programa de Funciones Financieras

Public Class Form1

    'Explicación:

    'Normalmente la gente simplemente se clave en la tasa de

    'interés anual como entero y no como%, así que tengo que

    'dividir la tasa por 100 y luego por 12 para obtener el

    'interés mensual. ¿Por qué signo negativo para el valor

    'presente (VP)? Porque esa es la cantidad que recibimos

    'en préstamo, por lo que debe ser negativa. El valor

    'futuro se establece en 0 porque para entonces usted

    'tiene pagar todo el pago. Por último, debido toma el

    'valor 0 como el pago vence al final del mes.

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        Me.Close()

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

        TextBox1.Clear()

        TextBox2.Clear()

        TextBox3.Clear()

        Label5.Text = ""

        Label10.Text = ""

        RadioButton1.Checked = False

        RadioButton2.Checked = False

        TextBox4.Clear()

        TextBox5.Clear()

        TextBox6.Clear()

        TextBox7.Clear()

        TextBox8.Clear()

        TextBox9.Clear()

        TextBox10.Clear()

        TextBox11.Clear()

        TextBox12.Clear()

        Label15.Text = ""

        Label13.Text = ""

        Label11.Text = ""

    End Sub

    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

        ' en la siguiente línea de código se comprueba si el caracter es dígito...

        'If (Not e.KeyChar.IsDigit(e.KeyChar)) Then

        '    ' de igual forma se podría comprobar si es caracter: e.KeyChar.IsLetter

        '    ' si es un caracter minusculas: e.KeyChar.IsLower ...etc

        '    If Not (e.KeyChar = Convert.ToChar(Keys.Back)) Then

        '        e.Handled = True ' esto invalida la tecla pulsada

        '    End If

        'End If

    End Sub

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click

        Dim x As New DataSet

        If datos.ejecutar_comandos("Insert into clientes values('" & TextBox6.Text & "','" & TextBox7.Text & "','" & TextBox8.Text & "','" & TextBox11.Text & "','" & TextBox10.Text & "','" & TextBox9.Text & "'," & TextBox12.Text & ")") = True Then

            MsgBox("Cliente Registrado", MsgBoxStyle.OkOnly, Title:="Financiera")

        Else

            MsgBox("Error, revise los datos", MsgBoxStyle.Critical, Title:="Financiera")

        End If

        x = datos.ejecutar_select("select * from clientes")

        Me.DataGridView1.DataSource = x.Tables(0)

    End Sub

    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click

        Dim cuota, n, g, a As Double

        a = Val(Label13.Text)

        n = Val(TextBox5.Text)

        g = Val(TextBox4.Text)

        If RadioButton1.Checked Then

            cuota = a - ((n - 1) * g)

        End If

        If RadioButton2.Checked Then

            cuota = a + ((n - 1) * g)

        End If

        Label15.Text = cuota

    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

        Dim vp, a, c, n, d, g, i, total, h As Double

        vp = Val(TextBox1.Text)

        n = Val(TextBox3.Text) * 12

        i = (Val(TextBox2.Text) / 100) / 12

        c = (((1 + i) ^ n) - 1) / (i * ((1 + i) ^ n))

        d = n / ((1 + i) ^ n)

        g = Val(TextBox4.Text) / i

        h = (((1 + i) ^ n) - 1) / (i)

        If RadioButton1.Checked Then

            a = (g * (c - d) + vp) / c

            total = (a * h) - (g * (h - n))

        End If

        If RadioButton2.Checked Then

            a = (vp - (g * (c - d))) / c

            total = (a * h) + (g * (h - n))

        End If

        Label13.Text = a

        Label11.Text = total

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim N As Integer

        Dim amt, payment, rate, total As Double

        amt = Val(TextBox1.Text)

        rate = (Val(TextBox2.Text) / 100) / 12

        N = Val(TextBox3.Text) * 12

        payment = Pmt(rate, N, -amt, 0, 0)

        total = FV(rate, N, -payment, 0, 0)

        'Label5.Text = Format(payment, "$#,##0.00")

        Label5.Text = payment

        Label10.Text = total

    End Sub

    Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click

        Dim x As New DataSet

        If datos.ejecutar_comandos("Insert into creditos values(" & TextBox1.Text & "," & TextBox2.Text & "," & TextBox3.Text & ",'" & Label5.Text & "','" & Label10.Text & "'," & TextBox12.Text & ")") = True Then

            MsgBox("Crédito Registrado", MsgBoxStyle.OkOnly, Title:="Financiera")

        Else

            MsgBox("Error, revise los datos", MsgBoxStyle.Critical, Title:="Financiera")

        End If

        x = datos.ejecutar_select("select * from creditos")

        Me.DataGridView1.DataSource = x.Tables(0)

    End Sub

    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click

        Dim x As New DataSet

        If datos.ejecutar_comandos("delete from clientes where cod_cre=" & TextBox12.Text & "") = True Then

            MsgBox("Cliente Eliminado", MsgBoxStyle.OkOnly, Title:="Financiera")

        Else

            MsgBox("Error, revise los datos", MsgBoxStyle.Critical, Title:="Financiera")

        End If

        x = datos.ejecutar_select("select * from clientes")

        Me.DataGridView1.DataSource = x.Tables(0)

    End Sub

End Class

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Creamos una clase llamada datos

Public Class datos

    Shared con As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Documents and Settings\DELL INSPIRON\Escritorio\vb.net\funciones financieras\financiera.mdb")'Ruta

    Shared Function ejecutar_select(ByVal consulta As String) As DataSet

        If CON.State = ConnectionState.Closed Then CON.Open()

        Dim da As New OleDb.OleDbDataAdapter(consulta, CON)

        Dim ds As New DataSet

        da.Fill(ds)

        CON.Close()

        Return ds

    End Function

    Shared Function ejecutar_comandos(ByVal comando As String) As Boolean

        If CON.State = ConnectionState.Closed Then CON.Open()

        Dim cm As New OleDb.OleDbCommand(comando, CON)

        Try

            cm.ExecuteNonQuery()

            Return True

        Catch ex As Exception

            Return False

        End Try

        CON.Close()

    End Function

End Class