从 InputBox 读取数据并插入一维数组

Question

我正在尝试从 InbutBox 插入数字并将它们保存到数组中以便稍后将它们显示到列表框中

我的 Vb.net 代码

Dim NumArray() As Double 
Dim ii As Integer = 10
    For ii = 0 To ii -1 
        NumArray = InputBox("Insert Number "+ii+"value", "Data Insertion", , , )
    Next

For ii = 0 To 10 -1
        ListBox1.Items.Add(NumArray(ii))
Next

它不工作。怎么了？有什么想法吗？

Answer 1

您应该做一些事情，尤其是如果您想继续使用 InputBox。

首先，您需要验证输入的值是有效的 Double。您可以通过实现Double.TryParse 方法来做到这一点。

接下来，与其尝试将值输入到数组中，不如将它们直接添加到您的控件中。

最后，我想指出您的 For/Next 循环永远不会执行。原因是因为首先，您将ii 的值从 10 覆盖为 0。接下来您尝试从 0 迭代到 -1，但不要更改循环的步长以向后迭代；默认情况下，For/Next 循环的步长为 +1。所以发生的情况是你的循环从 0 开始，检查它是否小于 -1，意识到它不是，然后什么也没有发生。

以下是实施建议的示例：

'Placeholder variables for the For/Next loop
Dim dbl_value As Double
Dim str_value As String

'Loop from 1-10
For ii As Integer = 1 To 10
    'Prompt for the currently iterated index's value
    str_value = InputBox("Insert number " & ii & " value", "Data Insertion")

    'Loop until the user enteres a valid Double
    Do Until Double.TryParse(str_value, dbl_value)
        'Inform the user that then did not follow instructions and re-prompt for a valid Double
        str_value = InputBox("That was not a valid Double. Please insert number " & ii & " value", "Data Insertion")
    Loop

    'Add the Double value to the ListBox
    ListBox1.Items.Add(dbl_value)
Next

Answer 2

三个选项：

Dim ii As Integer = 10
Dim NumArray(ii - 1) As Double 
For i As integer = 0 To ii -1 
    NumArray(i) = InputBox("Insert Number " + i + "value", "Data Insertion", , , )
Next

ListBox1.Items.AddRange(NumArray)

和：

Dim ii As Integer = 10
Dim NumArray As New List(Of Double)
For i As Integer = 0 To ii -1 
    Dim input As Integer = InputBox("Insert Number "+ii+"value", "Data Insertion", , , )
    NumArray.Add(input)
    ListBox1.Items.Add(input)
Next

和

ListBox1.Items.AddRange(Enumerable.Range(0, 10).Select(Function(i) InputBox("Insert Number " + i + "value", "Data Insertion", , , )).ToArray())