Question

我正在尝试为我的应用添加一个按钮。如果用户按下它，它应该显示警告。

我想将按钮添加到tableview.的部分标题中这是tableView:viewForHeaderInSection:

中的代码

UIImageView *headerView = [[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, 20)] autorelease];
...
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setFrame:CGRectMake(180, 4, 15, 15)];
UIImage *img=[UIImage imageNamed:@"myimg"];
[button setImage:img forState:UIControlStateNormal];
[button addTarget:self action:@selector(showMyAlert) forControlEvents:UIControlEventTouchUpInside];
[headerView addSubview:button];
return headerView;

在同一个班级，我有方法：

-(void)showMyAlert{
    NSLog(@"HERE SHOW ALERT");
    ...
}

按钮正确显示但是当我按下它时从不调用showMyAlert方法。有没有人知道我的代码有什么问题？谢谢，如果你能帮助我:)。

Answer 1

确保img不是零。如果为零，则按钮将没有图像，您将看不到任何内容。

Answer 2

修改下面的代码行，试试这样： -

[button addTarget:self action:@selector(showMyAlert:) forControlEvents:UIControlEventTouchUpInside];

-(IBAction)showMyAlert:(id)sender{
    NSLog(@"HERE SHOW ALERT");
    ...
}

Answer 3

在viewDidLoad中尝试这个，

-(void)viewDidLoad
{
UIView *headerView = [[UIView alloc] initWithFrame:CGRectMake(XXX, YYY, XXX, YYY)];
UIImageView *imageView = [[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, 20)] autorelease];
[headerView addSubview:imageView];
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setFrame:CGRectMake(180, 4, 15, 15)];
UIImage *img=[UIImage imageNamed:@"myimg"];
[button setImage:img forState:UIControlStateNormal];
[button addTarget:self action:@selector(showMyAlert) forControlEvents:UIControlEventTouchUpInside];
[headerView addSubview:button];
self.tableView.tableHeaderView = headerView;
}

Answer 4

将UIImageView更改为UIView并将其作为标题视图返回。

UIView *headerView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, 20)] autorelease];

Objective-c：action：@selector（xxxxxx）未调用

4 个答案: