Query RestEndPoint and Get values

jaykapalczynski

I am simply trying to query a rest endpoint (Feature Service) and get values from Specific fields

I dont think I need all the SDKs etc....I just want to read the result of a JSON string after querying a Rest EndPoint with a WHERE Clause.

Thoughts? Examples?

<SPAN class="keyword token">private</SPAN> <SPAN class="keyword token">void</SPAN> <SPAN class="token function">button1_Click</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">object</SPAN> sender<SPAN class="punctuation token">,</SPAN> EventArgs e<SPAN class="punctuation token">)</SPAN>

    <SPAN class="comment token">// Query a specific Rest EndPoint WHERE ID = ????</SPAN>

    <SPAN class="comment token">// Write Field 1, Field 2, Field 6 to variables</SPAN>

    <SPAN class="comment token">// Set variables to Textbox on Form</SPAN>

<SPAN class="punctuation token">{</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

jaykapalczynski

I think I got it working with this...Still testing

I added a section in there to specific outfields....this seems to be working as well....going to close this

            <SPAN class="keyword token">try</SPAN>
            <SPAN class="punctuation token">{</SPAN>
            <SPAN class="keyword token">string</SPAN> gpUrl <SPAN class="operator token">=</SPAN> <SPAN class="string token">"https://xyz.xyz.xyz.xyz/arcgis/rest/services/N/F/MapServer/0"</SPAN><SPAN class="punctuation token">;</SPAN>
            <SPAN class="keyword token">string</SPAN> whereClause <SPAN class="operator token">=</SPAN> <SPAN class="string token">"OBJECTID>1"</SPAN><SPAN class="punctuation token">;</SPAN>
            <SPAN class="keyword token">string</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN> outfieldsParam <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">string</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="number token">2</SPAN><SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">;</SPAN>
                outfieldsParam<SPAN class="punctuation token">[</SPAN><SPAN class="number token">0</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> <SPAN class="string token">"Address"</SPAN><SPAN class="punctuation token">;</SPAN>
                outfieldsParam<SPAN class="punctuation token">[</SPAN><SPAN class="number token">1</SPAN><SPAN class="punctuation token">]</SPAN> <SPAN class="operator token">=</SPAN> <SPAN class="string token">"State"</SPAN><SPAN class="punctuation token">;</SPAN>
            <SPAN class="keyword token">string</SPAN> outfieldsParam2 <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">string</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="token function">Join</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">","</SPAN><SPAN class="punctuation token">,</SPAN> outfieldsParam<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN> 
            <SPAN class="comment token">//string requestUrl = gpUrl + "/query?where=" + whereClause ;</SPAN>
            <SPAN class="keyword token">string</SPAN> requestUrl <SPAN class="operator token">=</SPAN> gpUrl <SPAN class="operator token">+</SPAN> <SPAN class="string token">"/query?where="</SPAN> <SPAN class="operator token">+</SPAN> whereClause <SPAN class="operator token">+</SPAN> <SPAN class="string token">"&outfields="</SPAN> <SPAN class="operator token">+</SPAN> outfieldsParam2<SPAN class="punctuation token">;</SPAN>

            HttpWebRequest request <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>HttpWebRequest<SPAN class="punctuation token">)</SPAN>WebRequest<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Create</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">Uri</SPAN><SPAN class="punctuation token">(</SPAN>requestUrl<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

            request<SPAN class="punctuation token">.</SPAN>KeepAlive <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">true</SPAN><SPAN class="punctuation token">;</SPAN>
            request<SPAN class="punctuation token">.</SPAN>Method <SPAN class="operator token">=</SPAN> <SPAN class="string token">"POST"</SPAN><SPAN class="punctuation token">;</SPAN>
            request<SPAN class="punctuation token">.</SPAN>AllowAutoRedirect <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">true</SPAN><SPAN class="punctuation token">;</SPAN>
            request<SPAN class="punctuation token">.</SPAN>CookieContainer <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">System<SPAN class="punctuation token">.</SPAN>Net<SPAN class="punctuation token">.</SPAN>CookieContainer</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            request<SPAN class="punctuation token">.</SPAN>ContentType <SPAN class="operator token">=</SPAN> <SPAN class="string token">"application/x-www-form-urlencoded"</SPAN><SPAN class="punctuation token">;</SPAN>

            StringBuilder paramString <SPAN class="operator token">=</SPAN> <SPAN class="keyword token">new</SPAN> <SPAN class="token class-name">StringBuilder</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            paramString<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Append</SPAN><SPAN class="punctuation token">(</SPAN>$<SPAN class="string token">"&f=json"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

            <SPAN class="keyword token">byte</SPAN><SPAN class="punctuation token">[</SPAN><SPAN class="punctuation token">]</SPAN> data <SPAN class="operator token">=</SPAN> Encoding<SPAN class="punctuation token">.</SPAN>ASCII<SPAN class="punctuation token">.</SPAN><SPAN class="token function">GetBytes</SPAN><SPAN class="punctuation token">(</SPAN>paramString<SPAN class="punctuation token">.</SPAN><SPAN class="token function">ToString</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            request<SPAN class="punctuation token">.</SPAN>ContentLength <SPAN class="operator token">=</SPAN> data<SPAN class="punctuation token">.</SPAN>Length<SPAN class="punctuation token">;</SPAN>

            Stream requestStream <SPAN class="operator token">=</SPAN> request<SPAN class="punctuation token">.</SPAN><SPAN class="token function">GetRequestStream</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            requestStream<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Write</SPAN><SPAN class="punctuation token">(</SPAN>data<SPAN class="punctuation token">,</SPAN> <SPAN class="number token">0</SPAN><SPAN class="punctuation token">,</SPAN> data<SPAN class="punctuation token">.</SPAN>Length<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            requestStream<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Close</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

            HttpWebResponse response <SPAN class="operator token">=</SPAN> <SPAN class="punctuation token">(</SPAN>HttpWebResponse<SPAN class="punctuation token">)</SPAN>request<SPAN class="punctuation token">.</SPAN><SPAN class="token function">GetResponse</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>

            <SPAN class="keyword token">string</SPAN> responseStr <SPAN class="operator token">=</SPAN> <SPAN class="token function">getStringFromWebResponse</SPAN><SPAN class="punctuation token">(</SPAN>response<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            Response <SPAN class="operator token">=</SPAN> responseStr<SPAN class="punctuation token">;</SPAN>
            <SPAN class="keyword token">return</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="operator token">!</SPAN><SPAN class="punctuation token">(</SPAN>responseStr<SPAN class="punctuation token">.</SPAN><SPAN class="token function">Contains</SPAN><SPAN class="punctuation token">(</SPAN><SPAN class="string token">"error"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
            <SPAN class="punctuation token">}</SPAN>

            <SPAN class="keyword token">catch</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="token class-name">Exception</SPAN> ex<SPAN class="punctuation token">)</SPAN>
            <SPAN class="punctuation token">{</SPAN>
                Console<SPAN class="punctuation token">.</SPAN><SPAN class="token function">WriteLine</SPAN><SPAN class="punctuation token">(</SPAN>ex<SPAN class="punctuation token">.</SPAN>Message<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">;</SPAN>
                <SPAN class="keyword token">return</SPAN> <SPAN class="keyword token">false</SPAN><SPAN class="punctuation token">;</SPAN>
            <SPAN class="punctuation token">}</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>