Question

我正在以编程方式打印标签，但我无法将其从屏幕上删除。我尝试了removeFromSuperview和lbl1.hidden = YES;以及lbl1= nil;，但没有使用它们。它始终保留在屏幕上，而我可以在调试中看到它从ELSE传递，如下面的代码所示。

我的问题在哪里？

-(void)reloadData
lbl1 = [[UILabel alloc] initWithFrame:CGRectMake(320, 530, 550, 200)];

if (result1 > result2 &&  al == YES)
{
    lbl1.userInteractionEnabled = YES;
    lbl1.text = @" Warning!! ";
    lbl1.tag = 30;
    lbl1.font = [UIFont fontWithName:@"Helvetica" size:18.0];
    lbl1.textColor = [UIColor redColor];
    lbl1.backgroundColor = [UIColor clearColor];
    lbl1.lineBreakMode = NSLineBreakByWordWrapping;
    lbl1.numberOfLines = 2;
    [self addSubview:lbl1];
    [lbl1 release];
}

else{

    //Non of them is removing the label.
    [lbl1 removeFromSuperview];
    lbl1= nil;
    lbl1.hidden = YES;
}

Answer 1

每次进入reloadData时，都会创建一个新标签，所以如果你重新加载并跳转到else，你就会创建一个标签，然后将其删除。

您需要将该标签保存为实例变量并将其删除/添加到reloadData中。

@property(nonatomic, strong) UILabel *lbl1;

在您的代码中，仅执行此操作：

self.lbl1 = [[[UILabel alloc] initWithFrame:CGRectMake(320, 530, 550, 200)] autorelease];

在你的reloadData中执行：

-(void)reloadData
lbl1 = [[UILabel alloc] initWithFrame:CGRectMake(320, 530, 550, 200)];

if (result1 > result2 &&  al == YES)
{
    self.lbl1.userInteractionEnabled = YES;
    //Etc...
}

else{

    [self.lbl1 removeFromSuperview];
}

Answer 2

试试这样：

-(void)reloadData
if(!lbl1)
lbl1 = [[UILabel alloc] initWithFrame:CGRectMake(320, 530, 550, 200)];

if (result1 > result2 &&  al == YES)
{
    lbl1.userInteractionEnabled = YES;
    lbl1.text = @" Warning!! ";
    lbl1.tag = 30;
    lbl1.font = [UIFont fontWithName:@"Helvetica" size:18.0];
    lbl1.textColor = [UIColor redColor];
    lbl1.backgroundColor = [UIColor clearColor];
    lbl1.lineBreakMode = NSLineBreakByWordWrapping;
    lbl1.numberOfLines = 2;
    [self addSubview:lbl1];
    [lbl1 release];
}

else{

    //Non of them is removing the label.
    [lbl1 removeFromSuperview];
    lbl1= nil;
    lbl1.hidden = YES;
}

Answer 3

尝试像这样删除....

if (result1 > result2 &&  al == YES)
{
    lbl1.userInteractionEnabled = YES;
    lbl1.text = @" Warning!! ";
    lbl1.tag = 30;
    lbl1.font = [UIFont fontWithName:@"Helvetica" size:18.0];
    lbl1.textColor = [UIColor redColor];
    lbl1.backgroundColor = [UIColor clearColor];
    lbl1.lineBreakMode = NSLineBreakByWordWrapping;
    lbl1.numberOfLines = 2;
    [self addSubview:lbl1];
    [lbl1 release];
}

else{

    //Non of them is removing the label.
    [[self.view viewWithTag:30] removeFromSuperview];
    lbl1= nil;
    lbl1.hidden = YES;
}

无法以编程方式删除标签

3 个答案: