iPhone sdk 如何在 UITableView 中添加具有第一个和最后一个数组计数的 UIButton？

Question

我只需要在我的 UITableView 中添加一个 UIButton 以及我的第一个和最后一个数组计数。我发现我们可以使用 tableFooterView，在我们的 tableview 下面添加取消按钮。但是我怎样才能在我的 tableview 上实现这个并且只使用第一个和最后一个数组值呢？这是我的代码，

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath   *)indexPath
{ 

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    //Adding a UIButton in last row

    NSInteger lastSectionIndex = [editTable numberOfSections] - 1;
    NSLog(@"lastSectionIndex:%d",lastSectionIndex);

    // Then grab the number of rows in the last section
    NSInteger lastRowIndex = [editTable numberOfRowsInSection:lastSectionIndex] - 1;
    NSLog(@"lastRowIndex:%d",lastRowIndex);

    // Now just construct the index path
    NSIndexPath *pathToLastRow = [NSIndexPath indexPathForRow:lastRowIndex inSection:lastSectionIndex];
    NSLog(@"last index:%@",pathToLastRow);

    if (pathToLastRow.row == lastRowIndex) 
    {
        NSLog(@"row enters");

        checkButton1 = [UIButton buttonWithType:UIButtonTypeCustom];
        [checkButton1 setFrame:CGRectMake(200, 0, 168, 168)];
        [checkButton1 addTarget:self
                         action:@selector(customActionPressed:)
               forControlEvents:UIControlEventTouchDown];
        [checkButton1 setBackgroundImage:[[UIImage imageNamed:@"Up Arrow.jpg"] stretchableImageWithLeftCapWidth:0.0 topCapHeight:0.0] forState:UIControlStateNormal];
        editTable.tableFooterView = checkButton1;
        [cell addSubview:checkButton1]; 
    }

现在我在 tableview 的每个单元格中都收到了按钮。如何仅将按钮提供给我的第一行和最后一行数组值？提前致谢。

Answer 1

将您的 if 条件更改为，

if ((lastSectionIndex == indexPath.section && lastRowIndex == indexPath.row ) || (indexPath.section == 0 && indexPath.row == 0 ))
{

看起来像这样

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
        UIButton *checkButton1 = [UIButton buttonWithType:UIButtonTypeCustom];
        checkButton1.tag = 100;//not recommended, I would suggest to use custom UITableViewCell class and add this button as subview inside its init method
        [checkButton1 setFrame:CGRectMake(200, 0, 168, 168)];
        [checkButton1 addTarget:self
                     action:@selector(customActionPressed:)
           forControlEvents:UIControlEventTouchDown];
        [checkButton1 setBackgroundImage:[[UIImage imageNamed:@"Up Arrow.jpg"] stretchableImageWithLeftCapWidth:0.0 topCapHeight:0.0] forState:UIControlStateNormal];
        [cell addSubview:checkButton1]; 
    }

   //Adding a UIButton in last row
   NSInteger lastSectionIndex = [editTable numberOfSections] - 1;
   NSLog(@"lastSectionIndex:%d",lastSectionIndex);

   // Then grab the number of rows in the last section
   NSInteger lastRowIndex = [editTable numberOfRowsInSection:lastSectionIndex] - 1;
   NSLog(@"lastRowIndex:%d",lastRowIndex);

   // Now just construct the index path
   NSIndexPath *pathToLastRow = [NSIndexPath indexPathForRow:lastRowIndex inSection:lastSectionIndex];
   NSLog(@"last index:%@",pathToLastRow);

   UIButton *checkButton1 = (UIButton *)[cell viewWithTag:100];//not recommended, I would suggest to use custom UITableViewCell class and add this button as subview inside its init method
   if ((lastSectionIndex == indexPath.section && lastRowIndex == indexPath.row ) || (indexPath.section == 0 && indexPath.row == 0 ))
    {
       checkButton1.hidden = NO;
    } else {
       checkButton1.hidden = YES;
    }

您不必在 .h 文件中声明 checkButton1。使它成为局部变量，如上所示。然后您可以设置隐藏属性以在不同单元格中隐藏/显示。除了执行上述操作，您还可以在自定义 UITableViewCell 类中创建此按钮并将隐藏属性设置为 cell.checkButton1.hidden = YES。为此，您需要子类化 UITableViewCell。