关闭 UIViewController 后如何重新加载 tableView

Posted 2023-02-27

【中文标题】关闭 UIViewController 后如何重新加载 tableView

【英文标题】：How to reload tableView after dismissing a UIViewController

【发布时间】：2012-04-07 16:10:47

【问题描述】：

我使用下面的方法来呈现一个名为 DictAddSubSecondCell 的 UIViewController：

// UIViewControler 1
- (IBAction)addWord:(id)sender
dictAddSubSecondCellController = [[DictAddSubSecondCell alloc] initWithNibName:@"DictAddSubSecondCell" bundle:nil];
[self presentModalViewController:dictAddSubSecondCellController animated:YES];
[dictAddSubSecondCellController release];

当我点击 DictAddSubSecondCell 中的按钮时：

- (IBAction)dismissAction:(id)sender 
[self dismissModalViewControllerAnimated:YES];

UIViewControler 1 的 tableView 没有重新加载它的数据，但是我在 viewWillApear 方法中添加了一个方法：

[self.table reloadData];

但它仍然无法正常工作。我对此一无所知。对我有什么建议吗？谢谢。

这里是 UIViewcontroller 1 的完整源代码：

//
//  DictAddSubSecond.m
//
//  Created by Samuel Armstrong on 4/8/12.
//  Copyright 2012 __MyCompanyName__. All rights reserved.
//

#import "DictAddSubSecond.h"
#import "DictionaryList.h"

@implementation DictAddSubSecond
@synthesize dictList, table, editButton;
@synthesize dictAddSubSecondCellController;

- (IBAction)addWord:(id)sender

    dictAddSubSecondCellController = [[DictAddSubSecondCell alloc] initWithNibName:@"DictAddSubSecondCell" bundle:nil];
    [self presentModalViewController:dictAddSubSecondCellController animated:YES];
    [dictAddSubSecondCellController release];


- (IBAction)toggleEdit 
    [self.table setEditing:!self.table.editing animated:YES];

    if (self.table.editing) 
        [editButton setTitle:@"Done"];
        [editButton setStyle:UIBarButtonItemStyleDone];
    
    else 
        [editButton setTitle:@"Edit"];
        [editButton setStyle:UIBarButtonItemStyleBordered];

    


- (IBAction)dismissAction:(id)sender

    [self dismissModalViewControllerAnimated:NO];


- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) 
        // Custom initialization
    
    return self;


- (void)didReceiveMemoryWarning

    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.


#pragma mark - View lifecycle

- (void)refreshTableData

    NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *file = [path stringByAppendingPathComponent:@"dictWithWords.tmp"];
    if (dictList == nil) 
        NSMutableArray *array = [[NSMutableArray alloc] initWithContentsOfFile:file];
        if ([array objectAtIndex:0] != nil) 
            dictList = [[NSMutableArray alloc] initWithCapacity:1];
            self.dictList = array;
            [array release];
        
        else
        
            dictList = [[NSMutableArray alloc] initWithCapacity:1];
        
    
    [self.table reloadData];



- (void)viewWillAppear:(BOOL)animated

    [super viewWillAppear:animated];

    [self refreshTableData];


- (void)someMethodToReloadTable:(NSNotification *)notification 

    [table reloadData];  



- (void)viewDidLoad

    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(someMethodToReloadTable) name:@"reloadTable" object:nil];




- (void)viewDidUnload

    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"reloadTable" object:nil];




- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);





#pragma mark -
#pragma mark Table View Data Source Methods

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

    return [dictList count];



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

    static NSString *MoveMeCellIdentifier = @"MoveMeCellIdentifier";
    UITableViewCell *cell = [self.table dequeueReusableCellWithIdentifier:MoveMeCellIdentifier];

    if (cell == nil) 
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:MoveMeCellIdentifier] autorelease];

        //A Boolean value that determines whether the cell shows the reordering control.
        cell.showsReorderControl = YES;

    
    NSUInteger row = [indexPath row];

    cell.textLabel.text = [dictList objectAtIndex:row];
    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    return cell;


#pragma mark -
#pragma mark Table View Delegate Methods
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath

    NSUInteger row = [indexPath row];
    [self.dictList removeObjectAtIndex:row];
    [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] 
                     withRowAnimation:UITableViewRowAnimationMiddle];



- (UITableViewCellEditingStyle)tableView:(UITableView *)tableView editingStyleForRowAtIndexPath:(NSIndexPath *)indexPath

    return UITableViewCellEditingStyleDelete;





// Asks the data source whether a given row can be moved to another location in the table view.
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath

    return YES;



//Tells the data source to move a row at a specific location in the table view to another location.
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath

    NSUInteger fromRow = [fromIndexPath row];
    NSUInteger toRow = [toIndexPath row];

    id object = [[dictList objectAtIndex:fromRow] retain];
    [dictList removeObjectAtIndex:fromRow];
    [dictList insertObject:object atIndex:toRow];
    [object release];



@end

【问题讨论】：

逻辑似乎是合理的。您是否可以使用日志消息或调试器来检查两件事：[self.table reloadData] 是否真的在那里被调用，如果是，您是否看到此后对您的委托方法的任何调用（例如numberOfRowsInSection:）？

我在 DictAddSubSecondCell 的 Documents/ 文件夹中修改了一个文件（使用 writeTOfile 方法的 NSArray 实例），我想在 UIViewControler 1 中显示修改后的结果。我只能通过重新加载 UIViewControler 1 才能看到新结果现在。

这意味着 TableView 在 modalview 关闭后没有重新加载

【参考方案1】：

尝试在viewDidAppear: 中调用它而不是viewWillAppear:。

【讨论】：

你确定 viewDidAppear: 被调用了吗？将 NSLog 语句放入其中以确保。委托方法很容易打错，调用时必须准确。

- (void)viewWillAppear:(BOOL)animated 在我关闭时被调用。

那么可能新数据没有正确添加到您的模型中。返回第一个视图控制器时使用日志语句检查数据。

问题解决了！虽然我将委托和数据源链接到它的文件所有者，但它看起来不起作用，所以我添加了 self.table.delegate = self; && self.table.datasource = self;在 viewDidLoad 方法中，它会正常工作。！