如何获取以'a'开头的组合框项目的计数 [英] How to get the count of the items of a combo box that starts with 'a'

问题描述

HI全部，



我有一个组合框，其值为a，a1，a2，b，b2。我如何获得以'a'开头的组合框的项目数。



请帮忙。



谢谢。

HI All,

I have a combo box with values like "a,a1,a2,b,b2". How do i get the count of the items of a combo box that starts with 'a'.

Please help.

Thanks.

推荐答案

在下面试试

try below

Dim mylines() As String = ComboBox1.Items.Cast(Of String).ToArray
Dim count As integer = mylines.Where(Function(s) s.StartsWith("a")).Count()

或者不使用LINQ

Or without using LINQ

Dim count As integer =0
For each item As String in myComboBox.Items
  If item.StartsWith("a") Then
    count += 1
  End If
Next

您可以使用 foreach 循环...或者Linq：

Well you could use a foreach loop...or Linq:

string[] items = new string[myComboBox.Items.Count];
myComboBox.Items.CopyTo(items, 0);
int count = items.Where(i => i.StartsWith("a")).Count();

我建​​议使用 Linq [ ^ ]与 StartsWith [ ^ ]字符串方法。



看看这里： LINQ查询示例 [ ^ ]



这类似于：

I'd suggest to use Linq[^] query together with StartsWith[^] string method.

Have a look here: LINQ query examples[^]

It would be something similar to:

Dim itmscnt As Integer = (From itm As Object In ComboBox1.Items
                          Where (itm.ToString.StartsWith("a"))).Count

MsgBox("Count of items starting with 'a': " & itmscnt.ToString)

注意： 未经测试！

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