blocks|key|2825936|text|Request.QueryString是一个NameValueCollection，但是只有当查询字符串采用通常的[name=value]*格式时，才会向其中添加项。如果不是，则为空。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2825937|如果您的QueryString的格式是?test=value，那么Request.QueryString.AllKeys.Contains("test")将执行您想要的操作。否则，您只能在Request.Url.Query上执行字符串操作。|2825938|entityMap^0|0|J|M|J|1L|D|0|4|B|J|B|X|18|2M|H|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|I|$]]

<code>Request.QueryString</code> is a <code>NameValueCollection</code>, but items are only added to it if the query string is in the usual <code>[name=value]*</code> format. If not, it is empty. 

If your <code>QueryString</code> was of the form <code>?test=value</code>, then <code>Request.QueryString.AllKeys.Contains("test")</code> would do what you want. Otherwise, you're stuck doing string operations on <code>Request.Url.Query</code>.

blocks|key|2825970|text|Request.QueryString.GetValues(null)将获得一个没有值的键列表|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2825971|Request.QueryString.GetValues(null).Contains("test")将返回true|2825972|entityMap^0|0|Z|0|0|1G|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

<code>Request.QueryString.GetValues(null)</code> will get a list of keys with no values

<code>Request.QueryString.GetValues(null).Contains("test")</code> will return true

blocks|key|197556|text|我写了一个扩展方法来解决这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|197557|public+static+bool+ContainsKey(this+NameValueCollection+collection,+string+key)
{
++++if+(collection.AllKeys.Contains(key))+
++++++++return+true;

+++++//+ReSharper+disable+once+AssignNullToNotNullAttribute
++++var+keysWithoutValues+=+collection.GetValues(null);
++++return+keysWithoutValues+!=+null+&&+keysWithoutValues.Contains(key);
}|code-block|syntax|javascript|197558|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I wrote an extension method to solve this task:

<pre><code>public static bool ContainsKey(this NameValueCollection collection, string key)
{
 if (collection.AllKeys.Contains(key)) 
 return true;

 // ReSharper disable once AssignNullToNotNullAttribute
 var keysWithoutValues = collection.GetValues(null);
 return keysWithoutValues != null &amp;&amp; keysWithoutValues.Contains(key);
}
</code></pre>

blocks|key|198340|text|Request.QueryString.ToString().Contains("test")|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|198341|这在寻找单个查询字符串参数的特殊情况下有效，例如MyFile.aspx?test|unstyled|offset|length|style|CODE|198342|对于更复杂、更普遍的情况，其他解决方案会更好。|198343|entityMap^0|0|O|G|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|P|8|@$G|Q|H|R|I|J]]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|F|7|T|8|@]|9|@]|A|$]]]|N|$]]

<pre><code>Request.QueryString.ToString().Contains("test")
</code></pre>

This works in the special case where you're looking for a single querystring parameter, e.g. <code>MyFile.aspx?test</code>

For more complex, general, cases then other solutions would be better.

blocks|key|3038899|text|我用这个。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3038900|if+(Request.Params["test"]+!=+null)
{
++++//Is+Set
}
else+if(Request.QueryString.GetValues(null)+!=+null+&&+
+++++++Array.IndexOf(Request.QueryString.GetValues(null),"test")+>+-1)
{
++++//Not+set
}
else
{
++++//Does+not+exist
}|code-block|syntax|javascript|3038901|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I use this.

<pre><code>if (Request.Params["test"] != null)
{
 //Is Set
}
else if(Request.QueryString.GetValues(null) != null &amp;&amp; 
 Array.IndexOf(Request.QueryString.GetValues(null),"test") &gt; -1)
{
 //Not set
}
else
{
 //Does not exist
}
</code></pre>

blocks|key|195765|text|试试这个，它解决了我的问题！它将计算查询字符串是否为值或为空，然后您可以使用键检查所需的查询字符串值。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|195766|++if+(!Page.IsPostBack)
++++++++{
+++++++++++if+(Request.QueryString.Count+>+0)
++++++++++++{
++++++++++++++++if+(Request.QueryString["departmentId"]+!=+null)
++++++++++++++++{
++++++++++++++++++++GetSurveyByDeptAndStatus(departmentId:+Request.QueryString["departmentId"],+status:+"Not+Surveyed");
++++++++++++++++++++rbListEmpsSurvey.Items[1].Selected+=+true;
++++++++++++++++}

++++++++++++++++else+if+(Request.QueryString["SurveyStatus"]+!=+null)
++++++++++++++++{
++++++++++++++++++++SatisfactionStatus+=+Request.QueryString["SurveyStatus"]+"";
++++++++++++++++++++GetSurveyByDeptAndStatus(status:+SatisfactionStatus);
++++++++++++++++++++GetDepartments();
++++++++++++++++}}}|code-block|syntax|javascript|195767|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

TRY this one, it solved my issue!
It will count either the query string has a value or empty and then you can check the required query string value with the Key.
<pre><code> if (!Page.IsPostBack)
 {
 if (Request.QueryString.Count &gt; 0)
 {
 if (Request.QueryString[&quot;departmentId&quot;] != null)
 {
 GetSurveyByDeptAndStatus(departmentId: Request.QueryString[&quot;departmentId&quot;], status: &quot;Not Surveyed&quot;);
 rbListEmpsSurvey.Items[1].Selected = true;
 }

 else if (Request.QueryString[&quot;SurveyStatus&quot;] != null)
 {
 SatisfactionStatus = Request.QueryString[&quot;SurveyStatus&quot;] &quot;&quot;;
 GetSurveyByDeptAndStatus(status: SatisfactionStatus);
 GetDepartments();
 }}}
</code></pre>

Within the context of an ASP.NET page, I can use Request.QueryString to get a collection of the key/value pairs in the query string portion of the URI.

For example, if I load my page using <code>http://local/Default.aspx?test=value</code>, then I can call the following code:

<pre><code>//http://local/Default.aspx?test=value

protected void Page_Load(object sender, EventArgs e)
{
 string value = Request.QueryString["test"]; // == "value"
}
</code></pre>

Ideally what I want to do is check to see if test exists at all, so I can call the page using <code>http://local/Default.aspx?test</code> and get a boolean telling me whether test exists in the query string. Something like this:

<pre><code>//http://local/Default.aspx?test

protected void Page_Load(object sender, EventArgs e)
{
 bool testExists = Request.QueryString.HasKey("test"); // == True
}
</code></pre>

So ideally what I want is a boolean value that tell me whether the test variable is present in the string or not.

I suppose I could just use regex to check the string, but I was curious if anybody had a more elegant solution.

I've tried the following:

<pre><code>//http://local/Default.aspx?test

Request.QueryString.AllKeys.Contains("test"); // == False (Should be true)
Request.QueryString.Keys[0]; // == null (Should be "test")
Request.QueryString.GetKey(0); // == null (Should be "test")
</code></pre>

This behavior is different than PHP, for example, where I can just use

<pre class="lang-php prettyprint-override"><code>$testExists = isset($_REQUEST['test']); // == True
</code></pre>

Check if unassigned variable exists in Request.QueryString

在ASP.NET页面的上下文中，我可以使用Request.QueryString来获取URI的查询字符串部分中的键/值对的集合。例如，如果我使用http://local/Default.aspx?test=value加载我的页面，那么我可以调用以下代码：//http://local/Default.aspx?test=...

问检查Request.QueryString中是否存在未赋值的变量
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问检查Request.QueryString中是否存在未赋值的变量EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问检查Request.QueryString中是否存在未赋值的变量
EN