如何使用字符串以不同順序顯示名稱？

Question

我遇到了我分配給Visual Basic 2012課程的問題。說明如下。到目前爲止，我只顯示輸入的名字，沒有別的。我怎樣才能讓它顯示所請求的序列中的名字和姓氏？

String問題：在文本框中輸入您的名字和姓氏。取名稱並將其顯示在顯示姓氏，名字的標籤框中。

文本框輸入：李四

標籤框：DOE，簡

我到目前爲止的代碼如下。謝謝你的幫助！

Private Sub btndisplay_Click(sender As Object, e As EventArgs) Handles btndisplay.Click 
    Dim fullname As String 
    Dim firstname As String 
    Dim indexnum As Integer 
    Dim lastname As String 

    fullname = fulltextbox.Text 

    indexnum = fullname.IndexOf(" ") 

    firstname = fullname.Substring(0, indexnum) 

    firstlabel.Text = firstname 
    fulltextbox.Focus() 
End Sub 

Private Sub fulltextbox_TextChanged(sender As Object, e As EventArgs) 
    firstlabel.Text = String.Empty 

    fulltextbox.SelectAll() 
End Sub 

Private Sub btnexit_Click(sender As Object, e As EventArgs) Handles btnexit.Click 
    Me.Close() 
End Sub 

Answer 1

你是在正確的軌道上，首先確定在空間位於：

indexnum = fullname.IndexOf(" ") 

現在基於該指標，可以將字符串分割成兩個字符串，firstname和lastname：

firstname = fullname.Substring(0, indexnum) 
lastname = fullname.Substring(indexnum+1) 

您需要使用indexnum+1而不是indexnum，否則您將包含間距字符。

最後，你組在一起再次使用string concatenation operator (&)：

firstlabel.Text = lastname & ", " & firstname 

---

的最後一個方法因而看起來像：

Private Sub btndisplay_Click(sender As Object, e As EventArgs) Handles btndisplay.Click 
    Dim fullname As String 
    Dim firstname As String 
    Dim indexnum As Integer 
    Dim lastname As String 

    fullname = fulltextbox.Text 

    indexnum = fullname.IndexOf(" ") 

    firstname = fullname.Substring(0, indexnum) 
    lastname = fullname.Substring(indexnum+1) 

    firstlabel.Text = lastname & ", " & firstname 
    fulltextbox.Focus() 
End Sub 

Answer 2

注意，這也不會，如果你的使用中工作縮寫。此外，我會從刪除fulltextbox.SelectAll()

Private Sub btndisplay_Click(sender As Object, e As EventArgs) Handles btndisplay.Click 

    Dim Names() As String = fulltextbox.Text.Split(" "c) 

    If Names.Count = 2 Then 
     firstlabel.Text = Names(1) + ", " + Names(0) 
    ElseIf Names.Count = 0 Then 
     MessageBox.Show("Please enter name.") 
    Else 
     MessageBox.Show("Invalid Nmae entered.") 
    End If 

    fulltextbox.Text = "" 

End Sub