objective-c里的方法指针IMP的用法

SGPopSelectView.h

@interface SGPopSelectView : UIView

@property (nonatomic, assign) SEL selector;

@property (nonatomic, assign) IMP functionIMP;

@end

 

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SGPopSelectView.m

@interface SGPopSelectView () <UITableViewDelegate, UITableViewDataSource>

@property (nonatomic, strong) UITableView *tableView;

@end 

@implementation SGPopSelectView

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

{  

    _selectedIndex = indexPath.row;

    [tableView reloadData];    

    self.functionIMP(self, _selector, indexPath.row);//当选择菜单的某一项时，调用方法指针指向的方法

}

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UIHotWordViewController.h

#import <UIKit/UIKit.h>

#import "REMenu.h"

#import "SGPopSelectView.h"

 

@interface UIHotWordViewController : UIViewController

@property (strong,nonatomic) REMenu *menu;

@property (retain, nonatomic) IBOutlet UIButton *btnHotWord;

@property (nonatomic, strong) SGPopSelectView *popView;

@property (nonatomic, strong) NSArray *selections;

@property (nonatomic, retain)  NSString *r;

 @end

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UIHotWordViewController.m

- (void)viewDidLoad {

    [super viewDidLoad];    

    self.selections = @[@"句子",@"作品",@"作者"];

    self.popView = [[SGPopSelectView alloc] init];

    self.popView.selector = @selector(rows_selected:);//指定selector

    self.popView.functionIMP = [self methodForSelector:@selector(rows_selected:)];//指定函数指针

}

-(void) rows_selected:(NSInteger) idx {

    NSLog(@"选择了项%d", idx);//选择菜单后会调用此方法

}