ios - 看不到属性错误

在某些属性上有错误消息。错误消息在以下代码中被注释掉。即使在其他文件中声明并合成了属性，也不明白为什么会收到此错误消息？

PlayersViewController.m

#import "PlayersViewController.h"
#import "Player.h"
#import "PlayerCell.h"


@implementation PlayersViewController

@synthesize players;


- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
#warning Potentially incomplete method implementation.
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
#warning Incomplete method implementation.
    // Return the number of rows in the section.
    return [self.players count];
}

- (UIImage *)imageForRating:(int)rating
{
    switch (rating) {
        case 1:return [UIImage imageNamed:@"1StarSmall.png"];
        case 2:return [UIImage imageNamed:@"2StarsSmall.png"];
        case 3:return [UIImage imageNamed:@"3StarsSmall.png"];
        case 4:return [UIImage imageNamed:@"4StarsSmall.png"];
        case 5:return [UIImage imageNamed:@"5StarsSmall.png"];

    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"PlayerCell"];
    Player *player = [self.players objectAtIndex:indexPath.row];
    cell.nameLabel.text = player.name; /*property 'nameLabel' not found on object of tupe "UITableViewCell" */
    cell.gameLabel.text = player.game; /*property 'gameLabel' not found on object of tupe "UITableViewCell" */
    cell.ratingImageView.image = [self imageForRating:player.rating]; /*property 'ratingImageView' not found on object of tupe "UITableViewCell" */
    return cell;
}

这些属性在以下两个文件中声明和实现：

PlayerCell.h

#import <Foundation/Foundation.h>

@interface Player : NSObject

@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *game;
@property (nonatomic, assign) int rating;

@end

PlayerCell.m

#import "Player.h"

@implementation Player

@synthesize name;
@synthesize game;
@synthesize rating;

@end

最佳答案

UITableViewCell没有名为nameLabel，gameLabel或ratingImageView的属性。如果您使用自己的自定义UITableViewCell子类，则需要告诉编译器您是在将消息发送到PlayerCell实例而不是UITableViewCell实例。

像这样做

PlayerCell *cell = (PlayerCell *) [tableView dequeueReusableCellWithIdentifier:@"PlayerCell"];

另外，您可以使用id，如果不使用点表示法，则编译器也不会出现问题，但是为了清楚起见，我将使用显式类版本。

id cell = [tableView dequeueReusableCellWithIdentifier:@"PlayerCell"];
[cell nameLabel].text = @""; //etc

顺便说一句-如果这是您的实际代码，那么您没有实例化UITableViewCells，这也可能会带来问题。

static NSString *CellIdentifier = @"Cell";

PlayerCell *cell = (PlayerCell *)[tableView dequeueReusableCellWithIdentifier:@"PlayerCell"];
if (nil == cell){
  cel = [[[PlayerCell alloc] yourInitMethodWithCellIdentifier:CellIdentifier] autorelease];
}
Player *player = [self.players objectAtIndex:indexPath.row];
cell.nameLabel.text = player.name;
cell.gameLabel.text = player.game;
cell.ratingImageView.image = [self imageForRating:player.rating];
return cell;