user26822: How can I get the bitcoin balance of a public key in C#?
E.g. for this public key: 1FqLoEpbQpMxow5bqEPpFbPVnBEbFcsg3J
How can I get its balance in C#?

user35760: Take a look at Blockparser: https://github.com/znort987/blockparser**
It will let you parse blockchain data to verify balances (among other things)

user6090: If you are ok with a third party service check out the Blockchain API.
They have a C# library and it's fairly easy to use.
If you need only the balance of an address you can use the code below as described on their BlockExplorer page:
 // calculate the balanace of an address by fetching a list of all its unspent outputs
 var outs = blockExplorer.GetUnspentOutputs("1EjmmDULiZT2GCbJSeXRbjbJVvAPYkSDBw");
 long totalUnspentValue = outs.Sum(x => x.Value);


26822: <p>How can I get the bitcoin balance of a public key in C#?</p>

<p>E.g. for this public key: 1FqLoEpbQpMxow5bqEPpFbPVnBEbFcsg3J</p>

<p>How can I get its balance in C#?</p>
 35760: <p>Take a look at Blockparser: <a href="https://github.com/znort987/blockparser" rel="nofollow">https://github.com/znort987/blockparser</a>**</p>

<p>It will let you parse blockchain data to verify balances (among other things)</p>
 6090: <p>If you are ok with a third party service check out the <a href="https://blockchain.info/api" rel="nofollow">Blockchain API</a>.</p>

<p>They have a C# library and it's fairly easy to use.</p>

<p>If you need only the balance of an address you can use the code below as described <a href="https://github.com/blockchain/api-v1-client-csharp/blob/master/docs/blockexplorer.md" rel="nofollow">on their BlockExplorer page</a>:</p>

<pre><code> // calculate the balanace of an address by fetching a list of all its unspent outputs
 var outs = blockExplorer.GetUnspentOutputs("1EjmmDULiZT2GCbJSeXRbjbJVvAPYkSDBw");
 long totalUnspentValue = outs.Sum(x =&gt; x.Value);
</code></pre>
