UITableView 从 NSArray 动态创建部分 [英] UITableView Dynamically Create Sections from NSArray

问题描述

我有以下数据结构，我无法更改(可能是这个问题最重要的部分):

I have the following data structure, which I cannot change (probably the most important part of this question):

<?xml version="1.0" encoding="us-ascii"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <array>
    <dict>
      <key>FirstName</key>
      <string>John</string>
      <key>LastName</key>
      <string>Adams</string>
    </dict>
    <dict>
      <key>FirstName</key>
      <string>Henry</string>
      <key>LastName</key>
      <string>Ford</string>
    </dict>
  </array>
</plist>

我可以成功地将其读入 Person(我创建的)类类型的 NSArray 并在 UITableView 中显示此列表>.

I can successfully read this into an NSArray of class type of Person (which I created) and well as show this list in a UITableView.

我现在想对这些数据做的是按部分显示，按姓氏的第一个字母显示，并显示SectionIndexList.

What I would like to do with this data now is show it in sections, by the first letter in their last name as well as show the SectionIndexList.

我如何转换这些数据(不是数据源)，或者保持原样并直接在我的 DataSource 中为 UITableView 查询它，以便我可以通过他们姓氏的第一个字母?

How can I transform this data (not the data source), or leave it intact and query it directly in my DataSource for UITableView so I can section it off by the first letter in their last name?

提前致谢.

推荐答案

你应该这样做:

NSString *filePath = [[NSBundle mainBundle] pathForResource:@"name_of_plist" ofType:@"plist"];
NSArray *personsFileArray = [NSArray arrayWithContentsOfFile:filePath];
// At this point what you have inside personsFileArray are NSDictionaries as defined in your plist file. You have a NSArray<NSDictionary*>.
NSMutableDictionary *indexedPersons = [[NSMutableDictionary alloc] init];
// I am assuming you have a class called Person
for each (NSDictionary *d in personsFileArray) {
   Person *p = [[Person alloc] initWithDictionary:d];
   NSString *firstLetter = [p.lastName substringToIndex:1];
   NSMutableArray *persons = indexedPersons[firstLetter];
   if (!persons) {
      persons = [[NSMutableArray alloc] init];
   }
   [persons addObject:p];
   [indexedPersons setObject:persons forKey:firstLetter];
}
// After this, you have a dictionary indexed by the first letter, and as key an array of persons. 
// Now you need to implement UITableViewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    NSString *firstLetter = [self.indexedPersons allKeys][section];
    return self.indexedPersons[firstLetter].count;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView 
{
    return [self.indexedPersons allKeys].count;
}

并为章节索引标题实现此方法；

And implement this methods for the section index titles;

- (nullable NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section;
- (nullable NSArray<NSString *> *)sectionIndexTitlesForTableView:(UITableView *)tableView;
- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index;

如果您有任何疑问，这里有很多教程:

If you have any doubts, there are plenty of tutorials:

http://www.appcoda.com/ios-programming-index-list-uitableview/

希望能帮到你！！

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