objective-c - 将对象从数组添加到字典

Question

我正在从 SQLite 数据库中获取行并尝试将它们插入到字典中。除了我不断收到错误!我收到错误消息“ARC 不允许将 Objective-C 指针隐式转换为‘const id *’”，我知道这意味着我在向字典中添加对象时无法使用指针。那么我该如何修复它以便将这些数组添加到字典中呢？

    NSArray *keyArray = [[NSMutableArray alloc] init ];
    NSArray *valueArray = [[NSMutableArray alloc ] init ];
    NSDictionary* dic;
    NSInteger dataCount = sqlite3_data_count(statement);
    while (sqlite3_step(statement) == SQLITE_ROW) {
        @try {
            for (int i = 0; i < dataCount; i ++)
            {
                NSString* key = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, i)];  
                NSString *value = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, i)];

                if ([value length] == 0)
                {
                    value = @"";
                }

                keyArray = [keyArray arrayByAddingObject:key];
                valueArray = [valueArray arrayByAddingObject:value];

            }

        }
        @catch (NSException *ex)
        {
            NSLog(@"%@,%@", [ex name], [ex reason]);
        }

        dic= [NSDictionary dictionaryWithObjects:valueArray forKeys:keyArray count:[keyArray count]];

Answer 1

dictionaryWithObjects:forKeys:count: 采用 C 风格的数组，而不是 NSArray 对象。 dictionaryWithObjects:forKeys: 可能会起作用，但您最好还是构建一个可变字典，完全绕过 NSArray。

NSDictionary* dic;
NSMutableDictionary *tmp = [NSMutableDictionary dictionary];

for (int i = 0; i < dataCount; i ++)
{
    NSString* key = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, i)];  
    NSString *value = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, i)];
    [tmp setObject:value forKey:key];
}
dict = tmp;