使用 fromCString 从 DS 中读取时解包可选值时意外发现 nil [英] unexpectedly found nil while unwrapping an Optional value while reading from DS with fromCString

问题描述

我正在从 dbtable 中读取数据，但在表的特定位置出现错误.我的 sql 没问题，因为我已经可以从同一个表中读取，但是在特定行我收到一个错误，我想知道如何处理这个错误.我不是在寻找解决我的数据库问题的解决方案，我只是在寻找处理错误的方法，因此它不会崩溃.

I am reading from a dbtable and get an error at a specific position of the table. My sql is ok, because I could already read from the same table, but at a specific row I get an error and I would like to know howto handle this error. I am not looking for a solution to solve my db-issue, I am just looking for handling the error, so it doesn't crash.

我有以下代码:

let unsafepointer=UnsafePointer<CChar>(sqlite3_column_text(statement, 2));
if unsafepointer != nil {
    sText=String.fromCString(unsafepointer)! // <<<<<< ERROR
} else {
   sText="unsafe text pointer is nil !";
}

我收到一个错误:

致命错误:在展开可选值时意外发现 nil"

"fatal error: unexpectedly found nil while unwrapping an Optional value"

在用<<<<<<<<<<<<代码标记的行错误.

不安全指针的值不是nil:

pointerValue : 2068355072

我该如何处理这个错误，这样我的应用才不会崩溃?

How can I handle this error, so my app is not crashing ?

推荐答案

另一个可能的解决方案是:

Another possible solution is this:

let unsafepointer=UnsafePointer<CChar>(sqlite3_column_text(statement, 2));
var sText = "unsafe text pointer is nil !";
if unsafepointer != nil{
    if let text = String.fromCString(unsafepointer) as String?{
        sText = text;
    }    
}

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