仅在Do While循环上入门

Question

我对无法解决这个问题感到沮丧。尝试了几种不同类型的循环来显示乘法表。我所得到的只是标签中的一行。我在做什么错了？

Private Sub btnDisplay_Click(sender As Object, e As EventArgs) Handles btnDisplay.Click

    Dim intNum As Integer
    Dim intCount As Integer
    Dim intAnswer As Integer
    Dim myString As String

    Integer.TryParse(txtNumber.Text, intCount)
    intNum = 0

    Do While intNum < 12
        intNum = intNum + 1
        intAnswer = intNum * intCount
        lblTable.Text = "    " & intNum.ToString() & " * " & intCount.ToString() & " = " & intAnswer.ToString()
    Loop

Answer 1

首先，您要将循环结果分配给相同的标签，因此只有一个标签。

如果要创建多个标签，则应在创建过程中创建它们：

Dim top_pos as integer = 30 ' first label's Top
Dim left_pos as integer = 30 ' first label's Left


For intNum = 1 to 12  ' Im assuming you want the table from 1 to 12

    intAnswer = intNum * intCount
    Dim lbl As New Label
    With lbl
        .text = Cstr(intNum) & " * " & Cstr(intCount) & " = " & Cstr(intAnswer)
        .location = New Point(left_pos,top_pos) 'set its position
        ... 'and so on
        Me.Controls.Add(lbl)
    End With

    top_pos = top_pos + 30 ' moves the position for the next label.

Next

Answer 2

从外观看，每次代码循环时，它将标签文本设置为当前结果，同时覆盖之前的结果。

如果您希望标签显示多行数据，可以尝试如下操作：

lblTable.Text &= "    " & intNum.ToString() & " * " & intCount.ToString() & " = " & intAnswer.ToString() & Environment.NewLine

最后的“ Environment.NewLine”将在每个结果之间添加换行符。

“ =”之前的“＆”用于附加到现有文本的末尾。这类似于这样做：

lblTable.Text = lblTable.Text & "..." & Environment.NewLine

此外，请注意。如果要在标签中显示多行，则可能需要将AutoSize属性设置为false并正确配置所需的标签大小。

Answer 3

在这一行：

lblTable.Text = "    " & intNum.ToString() & " * " & intCount.ToString() & " = " & intAnswer.ToString()

它仅存储最后的结果。

您需要将现有结果预先添加到新结果中。

Label1.Text &= "    " & intNum.ToString() & " * " & intCount.ToString() & " = " & intAnswer.ToString() & Environment.NewLine 

我在&之前添加了=，以便将新结果附加到Label1现有内容的末尾，并在末尾添加一个换行符整洁