Runtime AssociatedObject

22 Feb 2017

AssociatedObject 类关联对象

像对象中添加、获取、删除关联值

方法：接收：objc_setAssociatedObject(id object, const void *key, id value, objc_AssociationPolicy policy) 获取：objc_getAssociatedObject(id object, const void *key) 移除：objc_removeAssociatedObjects(id object)

简单的应用

demo地址：RuntimeAssociated

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    return 50;
}

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

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    NSString *text = objc_getAssociatedObject(cell, @"kCellTextLabelKey");
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Alert"
                                                                             message:text
                                                                      preferredStyle:UIAlertControllerStyleAlert];
    UIAlertAction *okAlert = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        objc_removeAssociatedObjects(cell);
    }];
    [alertController addAction:okAlert];


    [self presentViewController:alertController animated:YES completion:^{

    }];
}