RAZOR 语法

RAZOR 存在ASP.net 框架中，可以将服务器代码混合在html中使用。

文件名: *.cshtml, *.vbhtml

1.定义变量，使用变量（单行定义变量）

单行定义变量

@{var total=7;}
  @{var message = "欢迎到来";}
  @{var CurrentTime = DateTime.Now.ToString();}
  
<br /><br /><br /><br />
total 的value 是 @total     <br />
message value is @message<br />
当前时间是  @CurrentTime

多行定义变量

@{var total = 7;
var message = "欢迎到来";
var CurrentTime = DateTime.Now.ToString();
}

 

2.  转移字符   “

@{var myFilePath = @"c:MyFolder";}
@{var myQuote = "he said:"我非常高兴"";}
@{var myQuote2 = @"he said:""我非常高兴""";}

<p>

the path is  @myFilePath
</p>
<p>@myQuote</p>
<p>@myQuote2</p>

3. 对大小写敏感

@{
    var lastName = "Smith";
    var LastName = "Jones";
}

<p>

@lastName

@LastName
</p>

4. 使用request对象

<table border="1">
<tr>
    <td>Requested URL</td>
    <td>Relative Path</td>
    <td>Full Path</td>
    <td>HTTP Request Type</td>
</tr>
<tr>
    <td>@Request.Url</td>
    <td>@Request.FilePath</td>
    <td>@Request.MapPath(Request.FilePath)</td>
    <td>@Request.RequestType</td>
</tr>
</table>

5.  if..  else  代码结合，判断是get 还是post请求页面

@{
    
    var result = "";
    if(IsPost)
    {
        result = "post 请求";   
    }
    else
    {
        result = "get请求";   
    }
    
}

<form method="post" >
<input type="submit" name="Submit" value="Submit" />
<p>@result</p>
</form>

var result =0;  //必须初始化；然后编译器根据初始化的值 判断其类型

 

 

 

6. if.else 根据post的值实现相加计算出结果

@{
    
    var result =0;
    var reulstMessage = "";
    if(IsPost)
    {
        result = Request["text1"].AsInt() + Request["text2"].AsInt();
        reulstMessage = "相加的结果为:" + result;
    }

    
    
}
@*//action不填写也没事*@

<form method="post" action="">  
<p>
<label for="text1">数1</label>
<input type="text" name="text1"/>
</p>
<p>
<label for="text2">数2</label>
<input type="text" name="text2" />
</p>
<p>
<input type="submit" value="相加" name="Submit" />
</p>
<p>
@Html.Label("结果","result")
@Html.TextBox("result",@reulstMessage)   
</p>

</form>

7.  @: 输出字符串 ,以及 <text>…</text>输出多行

@{
    
   
    if(IsPost)
    {
       
    }
    else
    {
     @: The time is @DateTime.Now <br />
     @DateTime.Now  @: is the time   <br />
      <text>
    The time is: <br /> @DateTime.Now  <br /><br /></text>
    }

    
    
}

注意：@：后面有空格

8.  Whitespace 对定义变量的影响

@{var a=”345”;}    @{var a=   “345”;}  

@{var a

=”356”;}             

但是值不能换行 

@{var a=”34

5”;}   //错误的

9.注释

@{
    //注释1
    /*注释
     * 2*/
    
    @*注释3*@
    
    
}

10. var 变量类型，大多数时候都可以这样用。 有时候要强类型化比如 DateTime。 另外：@(total * 12)计算乘号

@{  
    Layout = "~/_SiteLayout.cshtml";
  
}

@{
    // Assigning a string to a variable.
    var greeting = "Welcome!";

    // Assigning a number to a variable.
    var theCount = 3;

    // Assigning an expression to a variable.
    var monthlyTotal = theCount + 5;

    // Assigning a date value to a variable.
    var today = DateTime.Today;

    // Assigning the current page's URL to a variable.
    var myPath = this.Request.Url;

    // Declaring variables using explicit data types.
    string name = "Joe";
    int count = 5;
    DateTime tomorrow = DateTime.Now.AddDays(1);
}

//下面使用变量
@{
    // Embedding the value of a variable into HTML markup.
    <p>@greeting, friends!</p>

    // Using variables as part of an inline expression.
    <p>The predicted annual total is: @( monthlyTotal * 12)</p>

    // Displaying the page URL with a variable.
    <p>The URL to this page is: @myPath</p>
}
@*//action不填写也没事*@

11.操作符，类型转化，类型检测

AsInt(),IsInt()

AsBool(),IsBool()

AsFloat(),IsFloat()

AsDecimal(),IsDecimal()

AsDateTime(),IsDateTime()

          ToString()

操作符，+ – */  == ,+=,-=,=,.,(),[],!,&& ||

@( 5+13)

@{var value1=150000;}

@{var value2=value1*2}

@(value2 / 2 )

12.  虚拟路径(  / )，物理路径( )

Server.MapPath 虚拟路径转换为物理路径   // ~标明虚拟路径

@{
    var dataFilePath = "~/dataFile.txt";
}
<!-- Displays a physical path C:WebsitesMyWebSitedatafile.txt  -->
<p>@Server.MapPath(dataFilePath)</p>

12.循环体

@for(var i = 10; i < 21; i++)
{
    <p>Line #: @i</p>
}

@{
    var countNum = 0;
    while (countNum < 50)
    {
        countNum += 1;
        <p>Line #@countNum: </p>
    }
}

 

<ul>
@foreach (var myItem in Request.ServerVariables)
{
    <li>@myItem</li>
}
</ul>

  集合对象（ARRAY 和DIcitory )

1）数组操作

@* Array block 1: Declaring a new array using braces. *@
@{
    <h3>Team Members</h3>
    string[] teamMembers = {"Matt", "Joanne", "Robert", "Nancy"};
    foreach (var person in teamMembers)
    {
        <p>@person</p>
    }
}

array indexof方法确定元素位置，反转数组输出

@{
    string[] teamMembers = {"Matt", "Joanne", "Robert", "Nancy"};
    <p>The number of names in the teamMembers array: @teamMembers.Length </p>
    <p>Robert is now in position: @Array.IndexOf(teamMembers, "Robert")</p>
    <p>The array item at position 2 (zero-based) is @teamMembers[2]</p>
    <h3>Current order of team members in the list</h3>
    foreach (var name in teamMembers)
    {
        <p>@name</p>
    }
    <h3>Reversed order of team members in the list</h3>
    Array.Reverse(teamMembers);
    foreach (var reversedItem in teamMembers)
    {
        <p>@reversedItem</p>
    }
}

2）字典操作

  字典存放分数，查看课程为test3的分数；并把课程为test4的分数设置为0

@{
    var myScores = new Dictionary<string, int>();
    myScores.Add("test1", 71);
    myScores.Add("test2",72);
    myScores.Add("test3",73);
    myScores.Add("test4", 74);
    
    
    }

  <p>test3 score is @myScores["test3"]</p>
  //给test4 赋值为0
  @(myScores["test4"]=0)

  <p>test4 score is @myScores["test4"]</p>

13。  try catch   (Handling Errors)

例子：读取的文件不存在，提示错误

@{
    var dataFilePath = "~/dataFile.txt";
    var fileContents = "";
    var physicalPath = Server.MapPath(dataFilePath);
    var userMessage = "Hello world, the time is " + DateTime.Now;
    var userErrMsg = "";
    var errMsg = "";

    if(IsPost)
    {
        // When the user clicks the "Open File" button and posts
        // the page, try to open the created file for reading.
        try {
            // This code fails because of faulty path to the file.
            fileContents = File.ReadAllText(@"c:atafile.txt");

            // This code works. To eliminate error on page,
            // comment the above line of code and uncomment this one.
            //fileContents = File.ReadAllText(physicalPath);
        }
        catch (FileNotFoundException ex) {
            // You can use the exception object for debugging, logging, etc.
            errMsg = ex.Message;
            // Create a friendly error message for users.
            userErrMsg = "A file could not be opened, please contact "
                + "your system administrator.";
        }
        catch (DirectoryNotFoundException ex) {
            // Similar to previous exception.
            errMsg = ex.Message;
            userErrMsg = "A directory was not found, please contact "
                + "your system administrator.";
        }
    }
    else
    {
        // The first time the page is requested, create the text file.
        File.WriteAllText(physicalPath, userMessage);
    }
}

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <title>Try-Catch Statements</title>
    </head>
    <body>
    <form method="POST" action="" >
      <input type="Submit" name="Submit" value="Open File"/>
    </form>

    <p>@fileContents</p>
    <p>@userErrMsg</p>

    </body>
</html>