获取单元格或文本字段在此单元格中的位置 [英] Get position of cell or text field in this cell

问题描述

我有一个拆分视图控制器:view &表视图.在这个表格视图中，我有带有文本字段的自定义单元格.我不知道我会有多少个单元格，所以它会自动生成.现在我正在尝试滚动到文本字段，当它成为FirstResponder 时.我试过这样的事情:

I have a split view controller: view & tableview. In this table view I have custom cells with text field. I don't know how many cells will I have, so it generate automatically. And now I'm trying scroll to textfield, when it becomeFirstResponder. I've tried something like this:

-(void) textFieldDidBeginEditing:(UITextField *)textField {
    CGPoint focusOnTextField = CGPointMake(0, 300 + textField.frame.origin.y);
    [scroller setContentOffset: focusOnTextField animated: YES];
}

300px - 我的 TableView 的起始位置.一切似乎都很好，但 textField.frame.origin.y 总是等于 0(就像 bounds.origin.y 顺便说一句).

300px - start position of my TableView. All seems alright, but textField.frame.origin.y always equal to 0 (like and bounds.origin.y btw).

我想如果获取单元格的位置，哪个文本字段处于活动状态，然后在 cell.frame.origin.y<上替换 textField.frame.origin.y ，我想我可以解决问题/code> 或类似的东西.

I thought I can solve a problem if get position of cell, which textfield is active, and then replace textField.frame.origin.y on cell.frame.origin.y or something like this.

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我忘了说我的 tableviews 滚动已禁用.我按照你的建议和代码示例并像这样解决它:

I forgot say that my tableviews scroll is disabled. I follow your advices and code examples and solve it like that:

- (UITableViewCell *)cellWithSubview:(UIView *)subview {

    while (subview && ![subview isKindOfClass:[UITableViewCell self]])
        subview = subview.superview;
    return (UITableViewCell *)subview;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField {
    UITableViewCell *activeCell = [self cellWithSubview:textField];

    float offsetValueY = 200 + activeCell.origin.y;
    CGPoint focusOnTextField = CGPointMake(0, offsetValueY);
    [scroller setContentOffset:focusOnTextField animated:YES];
}

知道吗?它正在工作！:-) 但它产生了一个新问题.当我开始编辑文本字段时，滚动条首先跳到顶部，然后才转到正确的位置.当我写 [scroller setContentOffset:focusOnTextField animation:NO]; 时，这个问题消失了，但滚动条没有平滑移动.这对我来说很糟糕:-) 那么我们如何解决它?

And know what? It's working! :-) But it create a new problem. When I begin editing textfield, scroller at first jump on top, and only then going to it correct position. When I write [scroller setContentOffset:focusOnTextField animated:NO]; and this problem disappear, but there is no smooth move of scroller. And this is bad to me :-) So how we can solve it?

推荐答案

这里是如何滚动到包含文本字段的单元格...

Here's how to scroll to a cell containing a text field ...

// find the cell containing a subview.  this works independently of how cells
// have been constructed.

- (UITableViewCell *)cellWithSubview:(UIView *)subview {

    while (subview && ![subview isKindOfClass:[UITableViewCell self]])
        subview = subview.superview;
    return (UITableViewCell *)subview;
}

您的想法是在编辑开始时触发该操作是正确的.只需使用单元格即可...

Your idea is correct to trigger that action when editing begins. Just do it using the cell...

- (void)textFieldDidBeginEditing:(UITextField *)textField {

    // find the cell containing this text field
    UITableViewCell *cell = [self cellWithSubview:textField];

    // now scroll using that cell's index path as the target
    NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];
    [self.tableView scrollToRowAtIndexPath:indexPath atScrollPosition:UITableViewScrollPositionTop animated:YES];
}

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