**代码如下** 怎么提取最外层新创建的对象
UIView *addCard = ({
UIButton *addCard = UIButton.new;
[footer addSubview:addCard];
self.addProject = addCard;
[addCard makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(0);
make.top.equalTo(0);
make.right.equalTo(0);
make.bottom.equalTo(0);
}];
[addCard setTitle:@"添加任务" forState:UIControlStateNormal];
[addCard setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
// [addCard addTarget:self action:@selector(addCard:) forControlEvents:UIControlEventTouchUpInside];
//使用ReactiveCocoa处理点击事件，相当于上面的addTarget:方法
//addCard点击事件
[[addCard rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(id x) {
//隐藏addCard
addCard.alpha = 0;
//输入框
UITextView *textView = ({
self.viewText = [UITextView new];
[footer addSubview:self.viewText];
[self.viewText makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(10);
// make.top.equalTo(3);
make.right.equalTo(-10);
make.bottom.equalTo(-44+2);
}];
//因为footer变大，所以改变tableView的contentInset
listTableView.contentInset = UIEdgeInsetsMake(46, 0, 88, 0);
//立即刷新视图
[self layoutIfNeeded];
_viewText;
});
self.textView = textView;
//初始化add按钮
UIButton *add = ({
UIButton *view = [UIButton new];
view.contentHorizontalAlignment=UIControlContentHorizontalAlignmentRight;
[view setTitle:NSLocalizedString(@"add", nil) forState:UIControlStateNormal];
[view setTitleColor:Global_trelloBlue forState:UIControlStateNormal];
view.titleLabel.font = [UIFont systemFontOfSize:15];
[footer addSubview:view];
[view makeConstraints:^(MASConstraintMaker *make) {
make.right.equalTo(-20);
make.bottom.equalTo(-1);
make.width.equalTo(100);
}];
[view sizeToFit];
//初始化后隐藏(为了动画效果)
view.alpha = 0;
//立即刷新
[self layoutIfNeeded];
//add点击事件，创建新的tast
[[view rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(id x) {
//textView判空
if (![textView.text isEqualToString:@""]) {
AddTaskApi *api = AddTaskApi.new;
//如果在没有task的列添加新的task，t_sort传0
api.t_sort = @(0);
//都上传0
// if (listTableView.model.tasks.count == 0) {
// api.t_sort = @(0);
// }
// else { //否则传当前列最后一个task的t_sort，再加0.1
// TaskModel *model = listTableView.model.tasks[listTableView.model.tasks.count-1];
// api.t_sort = @(model.t_sort.doubleValue+0.1);
// }
api.t_taskContent = textView.text;
api.t_projectId = @(_project_id.integerValue);
//当前列的id
api.t_panel_id = @(listTableView.model.id.integerValue);
//发起请求
[api startWithCompletionBlockWithSuccess:^(YTKBaseRequest *request) {
NewTasklistModel *model = request.responseModel;
//存在即失败（接口定义，只在失败时才返回status值）
if (model.status) {
}
else { //添加成功
textView.text = nil;
//更新数据源
[listTableView.model.task addObject:model];
//插入行
[listTableView insertRow:(listTableView.model.task.count-1)inSection:0 withRowAnimation:
UITableViewRowAnimationBottom];
//计算rowHeight
CGFloat rowHeight = [self tableView:listTableView heightForRowAtIndexPath:[NSIndexPath indexPathForRow:listTableView.model.task.count-1 inSection:0]];
//根据当前列高度和rowHeight决定列高度是否增加
//updateConstraints:方法更新autolayout
[listView updateConstraints:^(MASConstraintMaker *make) {
//增加新的rowHeight后list超出允许最大高度，之前不满最大高度
if (listTableView.cellTotalHeight > (kTotalCellMaxHeight+NavAndStatusBarHeight-_keyboardHeight-44) && (listTableView.cellTotalHeight-rowHeight) < (kTotalCellMaxHeight+NavAndStatusBarHeight-_keyboardHeight-44)) {
make.height.equalTo(listView.yyHeight+((kTotalCellMaxHeight+NavAndStatusBarHeight-_keyboardHeight-44)-(listTableView.cellTotalHeight-rowHeight)));
}
//增加新的rowHeight后list没有超过允许最大高度
if (listTableView.cellTotalHeight <= (kTotalCellMaxHeight+NavAndStatusBarHeight-_keyboardHeight-44)) {
make.height.equalTo(listView.yyHeight+rowHeight);
}
}];
//autolayout动画
[UIView animateWithDuration:0.25 animations:^{
[self layoutIfNeeded];
}];
//tableView滚动到最底部，显示新添加行
[listTableView scrollToRow:listTableView.model.task.count-1 inSection:0 atScrollPosition:UITableViewScrollPositionBottom animated:NO];
//改变原列的标题数量
UITextField *sourceListTableHeaderTF=(UITextField *)[self viewWithTag:[listTableView.model.id integerValue]];
sourceListTableHeaderTF.text=[NSString stringWithFormat:@"%@ %ld",listTableView.model.name,(unsigned long)listTableView.model.task.count];
}
} failure:^(YTKBaseRequest *request) {
}];
}
}];
view;
});
self.addBtn = add;
//初始化cancel按钮
UIView *cancel = ({
UIButton *viewCancel = [UIButton new];
viewCancel.contentHorizontalAlignment=UIControlContentHorizontalAlignmentLeft;
[viewCancel setTitle:NSLocalizedString(@"cancel", nil) forState:UIControlStateNormal];
[viewCancel setTitleColor:Global_trelloBlue forState:UIControlStateNormal];
viewCancel.titleLabel.font = [UIFont systemFontOfSize:15];
[footer addSubview:viewCancel];
[viewCancel makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(20);
make.bottom.equalTo(-1);
make.width.equalTo(100);
}];
[viewCancel sizeToFit];
viewCancel.alpha = 0;
[self layoutIfNeeded];
//cancel点击事件
@weakify(self, viewCancel, textView, footer, listView, add, addCard)
[[viewCancel rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(id x) {
@strongify(self, viewCancel, textView, footer, listView, add, addCard)
//footer高度还原
[footer updateConstraints:^(MASConstraintMaker *make) {
make.height.equalTo(44);
}];
//list减去footer增加的高度(在这里做是为了动效)
[listView updateConstraints:^(MASConstraintMaker *make) {
make.height.equalTo(listView.yyHeight-44);
}];
//tableView的contentInset还原
listTableView.contentInset = UIEdgeInsetsMake(46, 0, 44, 0);
//隐藏textView
textView.alpha = 0;
[UIView animateWithDuration:0.25 animations:^{
//cancel隐藏
viewCancel.alpha = 0;
//add隐藏
add.alpha = 0;
//addCard显示
addCard.alpha = 1;
[self.viewController.navigationController setNavigationBarHidden:NO animated:YES];
[self layoutIfNeeded];
}];
[textView resignFirstResponder];
}];
viewCancel;
});
self.viewCancel = cancel;
//addCard点击后动效
[footer updateConstraints:^(MASConstraintMaker *make) {
make.height.equalTo(44+44);
}];
[textView updateConstraints:^(MASConstraintMaker *make) {
make.top.equalTo(2);
}];
[listView updateConstraints:^(MASConstraintMaker *make) {
make.height.equalTo(listView.yyHeight+44);
}];
[UIView animateWithDuration:0.25 animations:^{
[self.viewController.navigationController setNavigationBarHidden:YES animated:YES];
add.alpha = 1;
cancel.alpha = 1;
[self layoutIfNeeded];
}];
//弹出键盘
[textView becomeFirstResponder];
}];
addCard;
});
![[Web front-end] Permulaan pantas Node.js](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Jika anda menggunakan atribut rujukan lemah global, ia akan kelihatan secara global dan ia tidak ada kaitan dengan cara objek itu dicipta.