iphone - Index like iOS 联系人应用

Question

我想创建一个 View ，例如 iOS 联系人应用，

Basically i want is, Vertical ABCDEFG.... which is located on right side of this image, when user clicks on character M i want to get character M How should i achieve this ? is there any iOS control which gives me this `ABCDEF...?

提前致谢。

编辑

- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView
{
    return [[NSArray arrayWithObject:UITableViewIndexSearch] arrayByAddingObjectsFromArray:
            [[UILocalizedIndexedCollation currentCollation] sectionIndexTitles]];
}

- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index
{
    if (title == UITableViewIndexSearch)
    {
        CGRect searchBarFrame = self.searchDisplayController.searchBar.frame;
        [tableView scrollRectToVisible:searchBarFrame animated:YES];

        return -1;
    }
    else {
        UILocalizedIndexedCollation *currentCollation = [UILocalizedIndexedCollation currentCollation];
        NSLog(@"selected charecter=%ld",(long)[currentCollation sectionForSectionIndexTitleAtIndex:index]);
        return [currentCollation sectionForSectionIndexTitleAtIndex:index-1];
    }
}

Answer 1

你需要实现这两个方法:

// return list of section titles to display in section index view (e.g. "ABCD...Z#")
- (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView;                                                    
// tell table which section corresponds to section title/index (e.g. "B",1))
- (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index;

与对应的数据源:

例如，如果你有一个数组

`@"Cat", @"Mouse", @"Dog", @"Horse", @"Duck", @"Monkey"`

然后您将返回并为 sectionIndexTitlesForTableView 排列如下:

`@[@"C", @"D", @"H", @"M"]`

因为 @"Dog" 和 @"Duck" 对应 @"D"，@"Mouse" 和 @"Monkey" 代表 @"M" 等等。

当然，对于 sectionForSectionIndexTitle，您返回该索引的相应索引。 (1 个用于 @"D"，3 个用于 @"M" 等)