ios - 为什么删除而不是添加。plist

Question

每当我保存数据时，我都有一个代码可以将数据添加到 plist 文件对象中。他们暗恋的更早了!

除了更多我还想要它们!这怎么可能？

我保存数据的代码:

// get paths from root direcory
    NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
    // get documents path
    NSString *documentsPath = [paths objectAtIndex:0];
    // get the path to our Data/plist file
    NSString *plistPath = [documentsPath stringByAppendingPathComponent:@"Data.plist"];

    // set the variables to the values in the text fields
    self.personName = nameEntered.text;
    self.phoneNumbers = [[NSMutableArray alloc] initWithCapacity:3];
    [phoneNumbers addObject:homePhone.text];
    [phoneNumbers addObject:workPhone.text];
    [phoneNumbers addObject:cellPhone.text];


    // create dictionary with values in UITextFields
    NSDictionary *plistDict = [NSDictionary dictionaryWithObjects: [NSArray arrayWithObjects: personName, phoneNumbers, nil] forKeys:[NSArray arrayWithObjects: @"Name", @"Phones", nil]];

    NSString *error = nil;
    // create NSData from dictionary
    NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 errorDescription:&error];

    // check is plistData exists
    if(plistData) 
    {
        // write plistData to our Data.plist file
        [plistData writeToFile:plistPath atomically:YES];
    }
    else 
    {
        NSLog(@"Error in saveData: %@", error);
        [error release];
    }

Answer 1

您每次都在用新数据覆盖 plist 文件。如果要追加，则需要先从 plist 文件加载现有数据，然后将新数据添加到该字典，然后写出更新后的字典。