Objective c 替换NSMutableArray中的指定词典
我正在尝试替换可变数组中的字典。 第1步到第4步应该很好,但是第5步到第6步我遇到了一些问题。您能告诉我如何使该功能正常工作:Objective c 替换NSMutableArray中的指定词典,objective-c,cocoa,Objective C,Cocoa,我正在尝试替换可变数组中的字典。 第1步到第4步应该很好,但是第5步到第6步我遇到了一些问题。您能告诉我如何使该功能正常工作: - (void) updatePlist { // 1: String with plist path: NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDom
- (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];
}
-(无效)更新列表{
//1:具有plist路径的字符串:
NSArray*Path=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask,是);
NSString*documentsDirectory=[paths objectAtIndex:0];
NSString*path=[documentsDirectory
stringByAppendingPathComponent:@“Object.plist”];
//2:创建包含当前对象的可变字典并写入
//“收藏夹”字符串的“是”:
NSMutableDictionary*mutDict=[NSMutableDictionary]
dictionaryWithDictionary:[DetailsDataSourceObjectAtIndex:detailIndex]];
[mutDict setObject:@“是”forKey:@“收藏”];
//3:生成包含当前对象名称的字符串:
NSString*nameString=[[detailsDataSource对象索引:detailIndex]
valueForKey:@“名称”];
//4:创建包含所有对象的可变数组:
NSArray*allObjectsArray=[[NSArray alloc]initWithContentsOfFile:path];
NSMUTABLEARRY*tmpMutArr=[NSMUTABLEARRY arrayWithArray:allObjectsArray];
//5:在tmpMutArr中搜索“Name”值与nameString匹配的字典:
int*索引;
对于(int i=0;i替换该行:
if([tempDict valueForKey:@"Name" == [NSString stringWithFormat:@"", nameString];)
这一行:
if([[tempDict valueForKey:@"Name"] isEqualToString: [NSString stringWithFormat:@"%@", nameString]])
因为这里使用的是字符串比较。正如Martin R在评论中指出的那样,您正在尝试将一个int值保存到int指针变量中
int index; //instead of 'int *index;'
这种改变应该会奏效
如果您先编写了int*index;
,然后编写了index=&i;
,这本可以工作的,因为您正在以这种方式保存指向整数的指针。但这似乎不是您想要做的
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]];
但将索引声明为整数已经解决了这两个错误。if(int i=0;我知道这不是应该的,我使用了一些示例代码将其组合在一起,这就是为什么我需要一些帮助来纠正它,因为这已经超过了我的经验水平。“i”甚至没有声明。但我想我应该是某种“for”循环,是的。字面上用“for”int*index
应该替换“if”e> 整数索引
。
[tmpMutArr replaceObjectAtIndex:index withObject:
[NSDictionary dictionaryWithDictionary:mutDict]];