Question

我正在尝试替换可变数组中的字典。步骤1到4应该是好的，但是我在步骤5 - 6中遇到了一些麻烦。你能否告诉我要使这个功能发挥作用需要做些什么：

- (void) updatePlist {
     // 1: String with plist path:
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
                                         NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory
             stringByAppendingPathComponent:@"Object.plist"];
    // 2: Create a mutable dictionary containing current object and write 
    // "Yes" to the "Favorite" string:
     NSMutableDictionary *mutDict = [NSMutableDictionary
      dictionaryWithDictionary:[detailsDataSource objectAtIndex:detailIndex]];
     [mutDict setObject:@"Yes" forKey:@"Favorite"];
     // 3: Make a string containing current object name:
     NSString *nameString = [[detailsDataSource objectAtIndex:detailIndex]
                                 valueForKey:@"Name"];
    // 4: Make a mutable array containing all objects:          
     NSArray *allObjectsArray = [[NSArray alloc] initWithContentsOfFile:path];
     NSMutableArray *tmpMutArr = [NSMutableArray arrayWithArray:allObjectsArray];
    // 5: Search for the dictionary in tmpMutArr with "Name" value matching nameString:
     int *index;        
     for(int i=0;i<[tmpMutArr count];i++) 
     {
         if([[tmpMutArr  objectAtIndex:i] isKindOfClass:[NSDictionary class]])
         {
             NSMutableDictionary *tempDict = [tmpMutArr  objectAtIndex:i];
             if([[tempDict valueForKey:@"Name"] isEqualToString:[NSString
                           stringWithFormat:@"%@", nameString]])nameString];)
             {
                 index = i;
             }
         }
     }
    // 6: Replace the old dictionary with the new one and write array to plist:
     [tmpMutArr replaceObjectAtIndex:index withObject:
                 [NSDictionary dictionaryWithDictionary:mutDict]];
     allObjectsArray = nil;
     allObjectsArray = [[NSArray alloc] initWithArray:tmpMutArr];
     [allObjectsArray writeToFile:path atomically:YES];
     }

编辑：

现在的问题是：

 for(int i=0;i<[tmpMutArr count];i++) 
 {
     if([[tmpMutArr  objectAtIndex:i] isKindOfClass:[NSDictionary class]])
     {
         NSMutableDictionary *tempDict = [tmpMutArr  objectAtIndex:i];
         if([[tempDict valueForKey:@"Name"] isEqualToString:
         [NSString stringWithFormat:@"%@", nameString]])nameString];)
         {
             index = i;   // Here 1
         }
     }
 }
 // ---------------------------- v And here 2
 [tmpMutArr replaceObjectAtIndex:index withObject:
              [NSDictionary dictionaryWithDictionary:mutDict]];

1：不兼容的整数到指针转换从'int'分配给'int';用＆amp;

取得地址

2：指向整数转换的不兼容指针将'int *'发送到NSUInteger类型的参数'（又名'unsigned int'）

Answer 1

替换行：

if([tempDict valueForKey:@"Name" == [NSString stringWithFormat:@"", nameString];)

这一行：

if([[tempDict valueForKey:@"Name"] isEqualToString: [NSString stringWithFormat:@"%@", nameString]])

因为你在这里使用字符串比较。

Answer 2

正如Martin R的评论中所指出的，您正在尝试将int值保存到int指针变量中。

int index; //instead of 'int *index;'

这种改变应该可以解决问题。

如果您编写了int *index;然后index = &i;，那可能会有效，因为您正在以这种方式保存指向整数的指针。但它似乎并不是你想要做的。

第二个错误是由于您为此方法提供了int指针而不是整数：

[tmpMutArr replaceObjectAtIndex:index withObject:
              [NSDictionary dictionaryWithDictionary:mutDict]];

但是将索引声明为整数可以解决这两个错误。

替换NSMutableArray中的指定字典

2 个答案: