ASP.Net/Language Basics/Function
Содержание
- 1 Call function (C#)
- 2 Define and call function (C#)
- 3 Define and call function in a page (VB.net)
- 4 Define function to change "HR" length (C#)
- 5 Function local variable (C#)
- 6 Function Parameter passed by Reference (C#)
- 7 Function Parameter passed by Value (C#)
- 8 Page level procedure (VB.net)
- 9 Simple function without parameters (C#)
- 10 Using out Parameters (C#)
Call function (C#)
<source lang="csharp">
<script Language="c#" runat="server">
void Page_Load() { DateTime DueDate; DateTime CheckOutDate; CheckOutDate = DateTime.Now; DueDate = FindDueDate(CheckOutDate); message1.Text = "
Checked OUT Date:" + CheckOutDate; message2.Text = "
Due date is " + DueDate.ToString("d"); } DateTime FindDueDate(DateTime CheckOutDate) { return CheckOutDate + TimeSpan.FromDays(14); }
</script> <html> <head> <title>Sample Function Page</title> </head> <body>
<asp:label id="message1" runat="server"/> <asp:label id="message2" runat="server"/>
</body> </html>
</source>
Define and call function (C#)
<source lang="csharp">
<script Language="c#" runat="server">
void Page_Load() { message1.Text=""; message1.Text+="
Calling Function 1..."; Function1(); message1.Text+="
Calling Function 2..."; Function2(); message1.Text+="
Calling Function 1..."; Function1(); } void Function1() { string Different = "in Function 1"; message1.Text+= Different; } void Function2() { string Different = "in Function 2"; message1.Text+= Different; }
</script> <html> <head> <title>Scope</title> </head> <body> <asp:label id="message1" runat="server"/> </body> </html>
</source>
Define and call function in a page (VB.net)
<source lang="csharp">
<%@ Page Language="VB" %> <html> <head>
<title>Simple ASP.NET Page</title> <script runat="server"> Sub SayHello() Response.Write("Hello, World!") End Sub </script>
</head> <body> <% SayHello %> </body> </html>
</source>
Define function to change "HR" length (C#)
<source lang="csharp">
<%@ Page Language="C#" Debug="true" %> <script runat="server">
void Page_Load() { if (IsPostBack) { lblMessage.Text = "First Line"; InsertLinebreak(Convert.ToInt32(NumberOptions.SelectedItem.Value), Convert.ToInt32(WidthOptions.SelectedItem.Value)); lblMessage.Text += "Second Line"; InsertLinebreak(Convert.ToInt32(NumberOptions.SelectedItem.Value), Convert.ToInt32(WidthOptions.SelectedItem.Value)); } } void InsertLinebreak(int NumLines, int Width) { for (int i=1; i<=NumLines; i++) {lblMessage.Text += "
";
} }
</script> <html> <head>
<title>Using Functions with Parameters</title>
</head> <body>
Choose the number and width of the linebreaks and then press submit <form runat="server"> <asp:RadioButtonList id="WidthOptions" runat="server"> <asp:ListItem value="100">100 pixels wide</asp:ListItem> <asp:ListItem value="300">300 pixels wide</asp:ListItem> <asp:ListItem value="600">600 pixels wide</asp:ListItem> </asp:RadioButtonList> <asp:DropDownList id="NumberOptions" runat="server"> <asp:ListItem value="1">1 Line</asp:ListItem> <asp:ListItem value="2">2 Lines</asp:ListItem> <asp:ListItem value="3">3 Lines</asp:ListItem> </asp:DropDownList> <asp:Button id="Button1" runat="server" text="Submit"></asp:Button>
<asp:Label id="lblMessage" runat="server"></asp:Label> </form>
</body> </html>
</source>
Function local variable (C#)
<source lang="csharp">
<script Language="c#" runat="server">
void Page_Load() { message1.Text=""; message1.Text+="
Calling Function 1..."; Function1(); message1.Text+="
Calling Function 2..."; Function2(); message1.Text+="
Calling Function 1..."; Function1(); } void Function1() { string Different = "Hello I"m the variable Different in Function 1"; message1.Text+= Different; } void Function2() { string Different = "Hello I"m the variable Different in Function 2"; message1.Text+= Different; }
</script> <html> <head> <title>Scope</title> </head> <body> <asp:label id="message1" runat="server"/> </body> </html>
</source>
Function Parameter passed by Reference (C#)
<source lang="csharp">
<%@ Page Language="C#" %> <script runat="server">
void Page_Load() { int a = 1; Increment(ref a); lblMessage.Text = a.ToString(); } void Increment(ref int Number) { Number += 1; }
</script> <html> <head>
<title>Demonstration of Passing a Parameter by Reference</title>
</head> <body>
<asp:Label id="lblMessage" runat="server"></asp:Label>
</body> </html>
</source>
Function Parameter passed by Value (C#)
<source lang="csharp">
<%@ Page Language="C#" %> <script runat="server">
void Page_Load() { int a = 1; Increment(a); lblMessage.Text = a.ToString(); } void Increment(int Number) { Number += 1; }
</script> <html> <head>
<title>Demonstration of Passing a Parameter by Value</title>
</head> <body>
<asp:Label id="lblMessage" runat="server"></asp:Label>
</body> </html>
</source>
Page level procedure (VB.net)
<source lang="csharp">
<%@ Page Language=VB Debug=true %> <script runat=server> Sub Page_Load(ByVal Sender as Object, ByVal E as EventArgs)
If IsPostBack Then DisplayInstructions("Final") Else DisplayInstructions("Initial") End If
End Sub Sub SubmitBtn_Click(Sender As Object, E As EventArgs)
lblResult.Text = "Result: " & AddNums( _ txtNumber1.Text, txtNumber2.Text)
End Sub Sub DisplayInstructions(Mode as String)
If Mode = "Initial" Then lblInstructions.Text = "Enter two numbers that " _ & "you want to add." Else lblInstructions.Text = "The results are " _ & "below." End If
End Sub Function AddNums(Num1 as Single, Num2 as Single) as Single
AddNums = Num1 + Num2
End Function </script> <HTML> <HEAD> <TITLE>Creating Your Own Procedures</TITLE> </HEAD> <Body LEFTMARGIN="40"> <form runat="server"> <asp:label
id="lblInstructions" runat="server"
/>
Enter a number:
<asp:textbox
id="txtNumber1" runat=server
/>
Enter a second number:
<asp:textbox
id="txtNumber2" runat=server
/>
<asp:button
id="butOK" text="Add" onclick="SubmitBtn_Click" runat="server"
/>
<asp:label
id="lblResult" runat="server"
/> </Form> </BODY> </HTML>
</source>
Simple function without parameters (C#)
<source lang="csharp">
<%@ Page Language="C#" Debug="true" %> <script runat="server">
void Page_Load() { lblMessage.Text = "First Line"; InsertLinebreak(); lblMessage.Text += "Second Line"; InsertLinebreak(); lblMessage.Text += "Third Line"; InsertLinebreak(); } void InsertLinebreak() {lblMessage.Text += "
";
}
</script> <html> <head>
<title>Simple Function Example</title>
</head> <body>
<form runat="server"> <asp:Label id="lblMessage" runat="server"></asp:Label> </form>
</body> </html>
</source>
Using out Parameters (C#)
<source lang="csharp">
<%@ Page Language="C#" %> <script runat="server">
void Page_Load() { int a = 1; int b; Increment(a, out b); lblMessage.Text = b.ToString(); } void Increment(int Number, out int Result) { Result = Number + 1; }
</script> <html> <head>
<title>Demonstration of using out Parameters</title>
</head> <body>
<asp:Label id="lblMessage" runat="server"></asp:Label>
</body> </html>
</source>