UITextView在UITableViewCell中顺利自动调整大小

I have a UITextView in a UITableViewCell contentview and allow the cell to autoresize so that the entered text is fully shown - what I am trying to accomplish is an autoresizing cell like the native iOS4 Contacts app has, when you enter "notes" for contact - i.e. when the contentSize of the textView changes - I call reloadRowsAtIndexPaths and in the delegate's heightForRowAtIndexPath I provide the new height for row - this does the job, however it is not nice and smooth like the contact's app - I am almost sure Apple uses some undocumented trick in that app to make the cell's contentView expand smooth and animated without calling reloadRowsAtIndexPaths. My question is how would you suggest to implement such functionality? I hope I didn't miss any details in explanation.

我在UITableViewCell内容视图中有一个UITextView，允许单元格自动调整，以便输入的文本完全显示 - 我想要完成的是一个自动调整单元格，如本机iOS4联系人应用程序，当您输入“注释”进行联系时 - 即当textView的contentSize发生变化时 - 我调用reloadRowsAtIndexPaths并在委托的heightForRowAtIndexPath中为行提供新的高度 - 这可以完成工作，但是它不像联系人的应用程序那样好看和平滑 - 我几乎可以肯定Apple使用了一些未记录的在该应用程序中的技巧，使单元格的contentView展开平滑和动画，而无需调用reloadRowsAtIndexPaths。我的问题是你如何建议实现这样的功能？我希望我没有错过任何解释细节。

2 个解决方案

#1

Try this code below, it will be help. You don't have to use any reload functions like reloadRowsAtIndexPaths.

试试下面的代码，这将有所帮助。您不必使用任何重装函数，如reloadRowsAtIndexPaths。

// textview delegate

// textview委托

- (void)textViewDidChange:(UITextView *)textView {
    if (contentView.contentSize.height > contentRowHeight) {

    contentRowHeight = contentView.contentSize.height;

    [theTableView beginUpdates];
    [theTableView endUpdates];

    [contentView setFrame:CGRectMake(0, 0, 300.0, contentView.contentSize.height)];
    }
}

// tableview delegate

// tableview委托

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
    CGFloat height;

    if (indexPath.row == 0)
        height = kTitleRowHeight;
    else 
        height = contentRowHeight;

    return height;
}

#2

I found the best way to solve this.

我找到了解决这个问题的最佳方法。

First off, of course, you're going to want to create your UITextView and add it to your cell's contentView. I created an instance variable of UITextView called "cellTextView" Here is the code that I used:

首先，当然，您将要创建UITextView并将其添加到单元格的contentView中。我创建了一个名为“cellTextView”的UITextView实例变量。这是我使用的代码：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];

    if (!cellTextView) {
        cellTextView = [[UITextView alloc] initWithFrame:CGRectMake(5.0, 5.0, cell.bounds.size.width - 30.0, cell.bounds.size.height - 10.0)]; // I use these x and y values plus the height value for padding purposes.
    }
    [cellTextView setBackgroundColor:[UIColor clearColor]];
    [cellTextView setScrollEnabled:FALSE];
    [cellTextView setFont:[UIFont boldSystemFontOfSize:13.0]];
    [cellTextView setDelegate:self];
    [cellTextView setTextColor:[UIColor blackColor]];
    [cellTextView setContentInset:UIEdgeInsetsZero];
    [cell.contentView addSubview:cellTextView];

    return cell;
}

Then, create an int variable called numberOfLines and set the variable to 1 in your init method. Afterwards, in your textViewDelegate's textViewDidChange method, use this code:

然后，创建一个名为numberOfLines的int变量，并在init方法中将该变量设置为1。然后，在textViewDelegate的textViewDidChange方法中，使用以下代码：

- (void)textViewDidChange:(UITextView *)textView
{
    numberOfLines = (textView.contentSize.height / textView.font.lineHeight) - 1;

    float height = 44.0;
    height += (textView.font.lineHeight * (numberOfLines - 1));

    CGRect textViewFrame = [textView frame];
    textViewFrame.size.height = height - 10.0; //The 10 value is to retrieve the same height padding I inputed earlier when I initialized the UITextView
    [textView setFrame:textViewFrame];

    [self.tableView beginUpdates];
    [self.tableView endUpdates];

    [cellTextView setContentInset:UIEdgeInsetsZero];
}

Finally, paste this code into your heightForRowAtIndexPath method:

最后，将此代码粘贴到heightForRowAtIndexPath方法中：

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    float height = 44.0;
    if (cellTextView) {
        height += (cellTextView.font.lineHeight * (numberOfLines - 1));
    }
    return height;
}

#1