架构x86_64的未定义符号：“_ OBJC_CLASS _ $ _ MoreButton”

Question

我正在尝试构建要在我的UIButton中使用的自定义UITableView，但是当我尝试编译时，我收到以下错误：

Undefined symbols for architecture x86_64:
  "_OBJC_CLASS_$_MoreButton", referenced from:
      objc-class-ref in MatchCenterViewController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

我已经检查了我的构建设置，据我所知，所有内容都已正确关联，因此我不确定是什么原因引起的。

MatchCenterViewController.h：

#import <UIKit/UIKit.h>
#import <Parse/Parse.h>
#import "AsyncImageView.h"
#import "SearchViewController.h"
#import "WebViewController.h"
#import "SLExpandableTableView.h"

@interface MatchCenterViewController : UIViewController <UITableViewDataSource>

@property (strong, nonatomic) NSString *itemSearch;
@property (strong, nonatomic) NSString *itemPriority;
@property (nonatomic, strong) NSArray *imageURLs;
@property (strong, nonatomic) NSString *matchingCategoryCondition;
@property (strong, nonatomic) NSString *matchingCategoryLocation;
@property (strong, nonatomic) NSNumber *matchingCategoryMaxPrice;
@property (strong, nonatomic) NSNumber *matchingCategoryMinPrice;
@property (strong, nonatomic) NSArray *matchCenterArray;
@property (strong, nonatomic) NSString *searchTerm;
@property (strong, nonatomic) NSString *itemURL;
@property (assign) NSInteger expandedSection;
@property (weak, nonatomic) IBOutlet UIButton *moreButton;
@property (strong) NSMutableSet *expandedSections;

@end

MatchCenterViewController.m（省略了相关部分）：

#import "MatchCenterViewController.h"
#import <UIKit/UIKit.h>

@interface MatchCenterViewController () <UITableViewDataSource, UITableViewDelegate>

@property (assign) NSInteger sectionIndex;
@property (nonatomic, strong) UITableView *matchCenter;
@property (nonatomic, assign) BOOL matchCenterDone;
@property (nonatomic, assign) BOOL hasPressedShowMoreButton;
@end


@interface MoreButton : UIButton
@property (assign) NSInteger sectionIndex;
@end

@implementation MatchCenterViewController


- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section {
    UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
    view.backgroundColor = [UIColor whiteColor];

    self.moreButton = [UIButton buttonWithType:UIButtonTypeCustom];
    self.moreButton.frame = CGRectMake(0, 0, 320, 44);
    [self.moreButton setImage:[UIImage imageNamed:@"downarrow.png"] forState:UIControlStateNormal];
    [self.moreButton addTarget:self action:@selector(moreButtonSelected:) forControlEvents:UIControlEventTouchUpInside];
    [view addSubview:self.moreButton];

    MoreButton *moreButton = [MoreButton buttonWithType:UIButtonTypeCustom];
    self.moreButton.frame = CGRectMake(0, 0, 320, 44);
    moreButton.sectionIndex = section;
    [self.moreButton setImage:[UIImage imageNamed:@"downarrow.png"] forState:UIControlStateNormal];
    [moreButton addTarget:self action:@selector(moreButtonSelected:) forControlEvents:UIControlEventTouchUpInside];
    [view addSubview:moreButton];

    return view;
}

- (void)moreButtonSelected:(MoreButton *)button {
    self.expandedSection = button.sectionIndex;
    [self.matchCenter reloadData];
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == self.expandedSection || indexPath.row <= 3) {
        return 65;
    }
    return 0;
}