ios - 尝试访问核心数据时出错
<p><p>我正在尝试获取我保存在一个核心数据对象中的值，但是我不断收到此错误</p>
<pre><code> *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+entityForName: nil is not a legal NSManagedObjectContext parameter searching for entity name 'Man''
</code></pre>
<p>结果错误发生在我编写的代码中，它尝试访问核心数据对象然后记录其内容，如下所示。</p>
<pre><code>if () {
// READ FROM CORE DATA
// WRITE TO CORE DATA
NSManagedObjectContext *context = ;
NSLog(@"%@", context);
// Test listing all FailedBankInfos from the store
NSFetchRequest *fetchRequest = [ init];
NSEntityDescription *entity = ; // This is where the error is happening.
;
NSError *error;
NSMutableArray *manufacturerDictionaryArray = [ init];
NSArray *fetchedObjects = ;
for (Manuf *manuf in fetchedObjects) {
NSLog(@"MANA: %@", man.mana);
NSLog(@"SURGE: %@", man.surge);
NSLog(@"HEALTH: %@", manuf.health);
etc//....
</code></pre>
<p>这就是我合成 managedObjectContext 和 fetchedResultsController 的方式</p>
<pre><code>// Core-Data variables used for fetching and managing the object
@synthesize fetchedResultsController = __fetchedResultsController;
@synthesize managedObjectContext = __managedObjectContext;
</code></pre>
<p>任何帮助将不胜感激。</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>你这样做:</p>
<pre><code>NSManagedObjectContext *context = ;
</code></pre>
<p>然后你访问这个:</p>
<pre><code>self.managedObjectContext
</code></pre>
<p>假设你的 <code>NSLog(@"%@", context);</code> 显示一个有效的 NSManagedObjectContext，那么我会这样做:</p>
<pre><code>NSEntityDescription *entity = ;
</code></pre>
<p>或者，将您的原始声明更改为:</p>
<pre><code>self.managedObjectContext = ;
</code></pre></p>
<p style="font-size: 20px;">关于ios - 尝试访问核心数据时出错，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/12666919/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/12666919/
</a>
</p>
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