我在GG中搜索千万找到UITableViewCell的解决方案更新数据但是所有人都向我展示了解决方案
UITableViewCell *cell=(UITableViewCell*)[self.tableView cellForRowAtIndexPath:indexPath];
但是对于所有可见的细胞，细胞都是零。我使用NSNotification将数据从一个方法发送到ViewController.m，而Reiever方法我希望通过indexPath将数据更新到单元格。但所有单元格都是零，无法更新。
这是我的代码 ViewController.h
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
@property(nonatomic, strong) IBOutlet UITableView *tableView;
@end
ViewController.m
@implementation ViewController
{
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(theReciever:) name:@"theSender" object:nil];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [recipes count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = @"SimpleTableCell";
UITableViewCell* cell = [self.tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
NSLog(@"cell nil");
}
NSString *idgame=@"Gamexyz";
cell.textLabel.text = idgame;
cell.tag=indexPath.row;
return cell;
}
-(void)theReciever:(NSNotification*)notif{
if([notif.object isKindOfClass:[packeData class]]){
packeData *data=[notif object];
NSString *key=data.key;
NSInteger *index=[key integerValue];
NSIndexPath *indexPath=[NSIndexPath indexPathWithIndex:index];
UITableViewCell *cell=(UITableViewCell*)[self.tableView cellForRowAtIndexPath:indexPath];
//UITableViewCell *cell=(UITableViewCell*)[self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:7 inSection:0]];
if(cell==nil)
{
NSLog(@"cell NULL");
}else{
cell.textLabel.text=data.process;
}
}else{
NSLog(@"ERR: object not recognised");
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
任何人都可以通过indexPath
帮助我或UITableViewCell更新数据的解决方案示例答案 0 :(得分：0)
注意：以下只是一个例子，您可以在新项目中执行此操作
您需要更改数据模型packeData，我们可以说key包含NSIntager，其中包含单元格的索引，process为{{1}将进度保存为字符串值，例如
NSString 中的
packeData.h并在#import <Foundation/Foundation.h>
@interface packeData : NSObject
@property (nonatomic, assign) NSInteger key; //holds index
@property (nonatomic, strong) NSString *process; //holds the progress info
@end
packeData.m@end
并在视图控制器中，你是tableview，
#import "packeData.h"
@implementation packeData
- (id)init //simply initialise it
{
self = [super init];
if(self)
{
}
return self;
}
中的
ViewController.h in #import <UIKit/UIKit.h>
#import "packeData.h"
@interface ViewController : UIViewController <UI TableViewDataSource,UITableViewDelegate>
@property (weak, nonatomic) IBOutlet UITableView *aTableView;
@property (strong,nonatomic) NSMutableArray *recipes; //array acts as datasource
@end
ViewController.m修改
替换以下方法
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(theReciever:) name:@"theSender" object:nil];
_recipes = [[NSMutableArray alloc]init]; //initilise your datasource
for(int j = 0 ;j< 20;j++)
{
// for my example i took some values
//initially put some initial values
packeData *data = [[packeData alloc] init];
data.key = j;
data.process = [NSString stringWithFormat:@"game_name_%d",j];
[_recipes addObject:data];
}
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[NSTimer scheduledTimerWithTimeInterval:0.8 target:self selector:@selector(PostNotification) userInfo:nil repeats:YES]; //just for testing
}
- (void)PostNotification
{
//i am simply posting the notification with some random values
packeData *data = [[packeData alloc]init];
data.key = arc4random()%15;
data.process = [NSString stringWithFormat:@"%ld",( data.key + 20)];
[[NSNotificationCenter defaultCenter] postNotificationName:@"theSender" object:data];
}
- (void)theReciever:(NSNotification *)notif
{
if([notif.object isKindOfClass:[packeData class]]){
packeData *data=[notif object];
NSInteger key=data.key;
NSInteger index= key;
//modify the datasource
packeData *recipes_data = [_recipes objectAtIndex:index]; //get the pocket present in array
recipes_data.process = data.process; //modify the recipes data
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:index inSection:0];
UITableViewCell *cell=(UITableViewCell*)[self.aTableView cellForRowAtIndexPath:indexPath];
if(cell==nil)
{
NSLog(@"cell NULL");
}else
{
[self.aTableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
// cell.textLabel.text=data.process; no need u already mofied the content in the datasource this will call the "cellForRowAtIndexPath" method and displays the process in place of game name
}
}else{
NSLog(@"ERR: object not recognised");
}
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [_recipes count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = @"SimpleTableCell";
UITableViewCell* cell = [self.aTableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
NSLog(@"cell nil");
}
packeData *idgame= [_recipes objectAtIndex:indexPath.row];
cell.textLabel.text = idgame.process; //initially contains game name
cell.tag=indexPath.row;
return cell;
}
@end
修改2
至于测试只是更改下面的方法，一旦模拟器启动应用程序滚动到下来，只有前5行只更新，等待5到10秒，滚动到顶部，你会看到所有的呼叫是更新用相同的过程5
- (void)PostNotification
{
//i am simply posting the notification with some random values
packeData *data = [[packeData alloc]init];
data.key = arc4random()%15; //15 change the number of rows
data.process = [NSString stringWithFormat:@"%ld",( data.key + arc4random() % 100)];
[[NSNotificationCenter defaultCenter] postNotificationName:@"theSender" object:data];
}
- (void)theReciever:(NSNotification *)notif
{
if([notif.object isKindOfClass:[packeData class]]){
packeData *data=[notif object];
NSInteger key=data.key;
NSInteger index= key;
//modify the datasource
packeData *recipes_data = [_recipes objectAtIndex:index]; //get the pocket present in array
recipes_data.process = data.process; //modify the recipes data
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:index inSection:0];
UITableViewCell *cell=(UITableViewCell*)[self.aTableView cellForRowAtIndexPath:indexPath];
if(cell==nil)
{
NSLog(@"cell NULL");
[self.aTableView reloadData]; //if cell is not visible then reload the whole table
}else
{
[self.aTableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
// cell.textLabel.text=data.process; no need u already mofied the content in the datasource this will call the "cellForRowAtIndexPath" method and displays the process in place of game name
}
}else{
NSLog(@"ERR: object not recognised");
}
}
形成上述测试你将看到前5个单元格即使不可见也会更新
答案 1 :(得分：0)
只需指定行的索引路径并重新加载...
NSIndexPath* path = [NSIndexPath indexPathForRow:3 inSection:0];
NSArray* rowsToReload = [NSArray arrayWithObjects:path, nil];
[tableView reloadRowsAtIndexPaths:rowsToReload withRowAnimation:UITableViewRowAnimationNone];