在UITableView中按字母顺序显示.plist键值

Question

我在iOS .plist中有一系列字典,结构类似于以下内容:

<plist version="1.0">
<array>
<dict>
    <key>name</key>
    <string>Afghanistan</string>
    <key>government</key>
    <string>Islamic Republic</string>
    <key>population</key>
    <integer>29121286
    </integer>
</dict>
<dict>
    <key>name</key>
    <string>Albania</string>
    <key>government</key>
    <string>Emerging Democracy</string>
    <key>population</key>
    <integer>2986952</integer>
</dict>

我正在尝试将<key>name</key>每个字典加载 到NSTableViewCell中,然后在NSTableView中按字母顺序显示它们,类似于iOS中的Contacts App.

下面是我的ViewControllers .h和.m.排序正常,但我无法将结果加载到TableViewCells中？

FirstViewController.h

#import <UIKit/UIKit.h>

@interface FirstViewController : UIViewController  <UITableViewDelegate,UITableViewDataSource>

{   
NSArray *sortedCountries;       
}

@property (nonatomic, retain) NSArray *sortedCountries;

@end

FirstViewController.m

#import "FirstViewController.h"

@implementation FirstViewController

@synthesize sortedCountries;



-(void)viewDidLoad  {

NSString *path = [[NSBundle mainBundle] pathForResource:@"countries"ofType:@"plist"];   
NSArray *countries = [NSArray arrayWithContentsOfFile:path];
NSSortDescriptor *descriptor = [[[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES] autorelease];
NSArray *sortedCountries = [[countries sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]] retain];

}

-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}

-(NSInteger)tableView:(UITableView *)tableView
numberOfRowsInSection:(NSInteger)section {

return 2;   
}

-(UITableViewCell *)tableView:(UITableView *)tableView
        cellForRowAtIndexPath:(NSIndexPath *)indexPath {

NSDictionary *country = [sortedCountries objectAtIndex:indexPath.row];
    NSString *countryName = [country objectForKey:@"name"];

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell =
[tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil) {

    cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault
                                   reuseIdentifier:CellIdentifier] autorelease];

}

cell.textLabel.text = countryName;
return cell;        
} 

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

}

- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;

}


- (void)dealloc {

[sortedCountries release];

[super dealloc];
}

@end

编辑:这里有 另一个问题.

Answer 1

将ivar添加到头文件中视图控制器的@interface:

@interface MyViewController : UITableViewController
{
    ...
    NSArray *sortedCountries;
}

添加此代码(按国家名称读取和排序plist)到视图控制器的initWith...方法:

NSArray *countries = [NSArray arrayWithContentsOfFile: pathToPlist];
// Now the array holds NSDictionaries, sort 'em:
NSSortDescriptor *descriptor = [[[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES] autorelease];
sortedCountries = [[countries sortedArrayUsingDescriptors:[NSArray arrayWithObject:descriptor]] retain];

然后使用以下代码段提取值:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSDictionary *country = [sortedCountries objectAtIndex:indexPath.row];
    NSString *countryName = [country objectForKey:@"name"];
    NSString *governmentType = [country objectForKey:@"government"];
    NSSInteger population = [[country objectForKey:@"population"] integerValue];
    // ... do something with countryName, governmentType, population
}

不要忘记发布sortedCountries:

- (void)dealloc
{
    ...
    [sortedCountries release];
    [super dealloc];
}