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Line 45:
Line 45: − + − NPC villager = null;+ + + − // crash: 'System.NullReferenceException' in Netcode.dll+ − + + + + − // this is okay+ − if (villager != null && villager.name == "Abigail") − </source></li>
Modding:Migrate to Stardew Valley 1.3 (view source)
Revision as of 23:53, 30 March 2018
, 23:53, 30 March 2018→Net types: update null behaviour
crop.dead.Set(true);
crop.dead.Set(true);
</source></li>
</source></li>
<li>Net types can't handle implicit casting on null net fields. Always check for null before comparing or implicitly casting to a value type:
<li>Quirk: when using [https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/null-conditional-operators null-conditional operators] with [https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/value-types value-type] net fields (like <tt>NetBool</tt> and <tt>NetInt</tt>), '''missing values will be equal to both null and <tt>default(T)</tt>''':
<source lang="c#">
<source lang="c#">
Item item = null;
if (item?.category == null && item?.category == 0) // both true
</source>
When comparing to the default value, check for null first to avoid that issue:
if (villager?.name == "Abigail")
<source lang="c#">
Item item = null;
if (item != null && item.category == 0)
</source>
</li>
</ul>
</ul>