textbox_changed和button问题

Question

我有三个textbox和一个button，button是disable的。我想要当textbox1,2,和3不是空的（有输入数据），button1才enable.如何用timer检查又太浪费资源，用textbox1,2,3的textchanged检查代码又太长。有什么优秀的方法呢,最好是代码短，效率高?谢谢

Answer 1

請參考看看

 Private Sub TextBox_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged, TextBox2.TextChanged, TextBox3.TextChanged
  Button1.Enabled = (TextBox1.Text.Length > 0 And TextBox2.Text.Length > 0 And TextBox3.Text.Length > 0)
 End Sub

 

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Shadowと愉快なコード達

Answer 2

跑個迴圈也可以,但如果只有三個textbox的話,還是用Shadow大的方法比較快,但超過5個我覺得用以下方法會好寫一點

ASPX :

 <asp:Panel ID="P_table" runat="server">
        <asp:TextBox ID="TextBox1" runat="server" AutoPostBack="true"></asp:TextBox>
        <asp:TextBox ID="TextBox2" runat="server" AutoPostBack="true"></asp:TextBox>
        <asp:TextBox ID="TextBox3" runat="server" AutoPostBack="true"></asp:TextBox>
    </asp:Panel>
    <asp:Button ID="Button1" runat="server" Text="Button" Visible="false" />

.aspx.vb :

Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
 Dim final As Integer = 0

 For i As Integer = 1 To 3

 Dim tx As TextBox = CType(P_table.FindControl("TextBox" & i), TextBox)

 If tx.Text <> "" Then

 final += 1

 End If

 Next


 If final = 3 Then

 Me.Button1.Visible = True

 End If
 End Sub

 

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coding or not

Answer 3

这个代码，还可以这样写啊！长知识了!

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忧郁的蓝色天空