UITableViewCell系列之(一)让你的cell支持二次编辑

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self.tableView registerNib:[UINib nibWithNibName:NSStringFromClass([WSEnableEditCell class]) bundle:nil] forCellReuseIdentifier:@"enableEditCell"];
    
    // self-sizing
    self.tableView.estimatedRowHeight = 200.f;
    self.tableView.rowHeight = UITableViewAutomaticDimension;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    
    return self.contentTexts.count;;
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    WSEnableEditCell *cell = [tableView dequeueReusableCellWithIdentifier:@"enableEditCell"];
    
    [cell setContent:self.contentTexts[indexPath.row]];
    cell.selected = NO;
    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"选中:%ld行",indexPath.row);
    
    // 0.0. 如果，当前正处在编辑状态，那么再次点击cell就保存内容、结束编辑（退出键盘）
    //      否则，进入编辑状态
    if ([self endEditForIndexPath:indexPath]) return;
    
    // 0.1. 保存点击的那一行
    editingIndexPath = indexPath;
    // 1.1. 获取点击的那一行在view上的frame
    CGRect rectInView = [self getCellRectInView:self.view forIndexPath:indexPath];
    // 1.2. 根据frame获取cell
    WSEnableEditCell *cell = [self getCellInTableView:tableView ForRect:rectInView];
    // 1.3. 把textView添加到cell上
    [self addTextView:self.textView toCell:cell];
    
}

// 0. 如果，当前正处在编辑状态，那么再次点击cell就保存内容、结束编辑（退出键盘）；否则，进入编辑状态
- (BOOL)endEditForIndexPath:(NSIndexPath *)indexPath {
    
    isEditing = !isEditing;
    if (!isEditing) {
        
        if (![indexPath isEqual:editingIndexPath]) indexPath = editingIndexPath;
        
        [self.view endEditing:YES];
        [self.tableView setScrollEnabled:YES];
        self.contentTexts[indexPath.row] = self.textView.text;
        // [cell setContent:self.textView.text];
        [self.tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
        [self.textView removeFromSuperview];
        
        [self.tableView setScrollEnabled:YES];
        return YES;
    } else {
        [self.tableView setScrollEnabled:NO];
        return NO;
    }
}

// 1.获取cell 在 屏幕上的 frame
- (CGRect)getCellRectInView:(UIView *)view forIndexPath:(NSIndexPath *)indexPath {
    CGRect rectInTableView = [self.tableView rectForRowAtIndexPath:indexPath];
    CGRect rect = [self.tableView convertRect:rectInTableView toView:view];
    return rect;
}

// 2.获取显示的所有cell，遍历数组中每个cell的frame，找到点击的那个cell
- (WSEnableEditCell *)getCellInTableView:(UITableView *)tableView ForRect:(CGRect)rect {
    NSArray *visibleCells = [tableView visibleCells];
    for (WSEnableEditCell *cell in visibleCells) {
        CGRect frame = [tableView convertRect:cell.frame toView:self.view];
        if (CGRectEqualToRect(frame, rect)) {
            return cell;
        }
    }
    return nil;
}

// 3.给cell添加UITextView
- (void)addTextView:(UITextView *)textView toCell:(WSEnableEditCell *)cell {
    textView.frame = cell.ContentLabel.frame;
    textView.text = cell.ContentLabel.text;
    [cell.contentView addSubview:textView];
    [textView becomeFirstResponder];
}