iphone - 在 iOS 中实现搜索历史功能

Question

我现在有一个搜索页面，它将加载网络服务的结果列表，但是当我返回搜索页面时，我想“保存”无论输入什么(例如“resto italian”)，然后将该条目和之前的条目显示到下面的表格 View 中，如下图所示:

我的计划是使用属性列表序列化——如果还没有列表，创建一个名为 history.plist 的属性列表，并用每个搜索词填充它，并在 TableView 中显示最接近的十个像上面一样。

我尝试过的:

// should create history.plist
- (NSString *)dataFilePath {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    return [documentsDirectory stringByAppendingString:@"history.plist"];
}

/* This is the action for when 'search' is clicked - calls the method above to create 
a new plist if it's not already created. 
I then try to display the contents of the of the file in the textfield itself 
(for testing purposes) but it's not saving/displaying properly at the moment. */

- (IBAction)saveHistory:(id)sender {        
    NSString *filePath = [self dataFilePath];
    if([[NSFileManager defaultManager] fileExistsAtPath:filePath])
    {
       NSArray *array = [[NSArray alloc] initWithContentsOfFile:filePath];
       for (int i = 0; i < (sizeof(array)); i++) {
            UITextField *theField = self.searchHistory;
            theField.text = [NSString stringWithFormat:@"%@", array];
       }
    }        
    UIApplication *app = [UIApplication sharedApplication];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillResignActive:) name:UIApplicationWillResignActiveNotification object:app];        
}

任何指向尝试执行此操作的教程的链接、对我应该做什么的建议或对我现有内容的改进都将不胜感激。

Answer 1

这应该可以解决问题:

// This is inside viewDidLoad    
UIApplication *myApp = [UIApplication sharedApplication];
[[NSNotificationCenter defaultCenter] addObserver:self     
          selector:@selector(applicationDidEnterBackground:)                                                                
          name:UIApplicationDidEnterBackgroundNotification
          object:myApp];

// This is inside my table view - where I'm loading the file data to display in table cells
NSString *myPath = [self dataFilePath];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:myPath];
if (fileExists) {
   NSArray *values = [[NSArray alloc] initWithContentsOfFile:myPath];
      for (int i = 0; i < values.count; i++) {
         cell.historyDisplay.text = [NSString stringWithFormat:@"%@", [values objectAtIndex:i]];
      }
}

// This is the file path for history.plist
- (NSString *)dataFilePath {
    NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    return [[path objectAtIndex:0] stringByAppendingString:@"history.plist"];
}

// This is my search button - I want to save whatever was typed in the text field, into history.plist, to display in my tableview whenever a user goes to it.     
- (IBAction)saveHistory:(id)sender {
    NSMutableArray *values = [[NSMutableArray alloc]initWithContentsOfFile:[self dataFilePath]];
    if(searchInputTextField.text.length > 0)
         [values addObject:searchInputTextField.text];
    [values writeToFile:[self dataFilePath] atomically:YES];    
    [leTableView reloadData];
}