ios - 如何为具有动态宽度的 UIButtons 设置背景？

Question

我有 3 个按钮图像，分别名为 edit_category_left_up、edit_category_middle_up 和 edit_category_right_up

我已经编写了代码来创建具有动态宽度的按钮，现在我需要使用上面的 3 张图片设置这些按钮的背景，如下图所示

这是我当前创建动态按钮的代码

-(void) addDynamicButtonsForCategories
{
    _adcImage.hidden=YES;
    _makeADCLabel.hidden=YES;

    float x=0; float y=0; float frameHeight=_subADCView.frame.size.height;
    NSString *titleString=@"";
    for(int i = 0; i < 15; i++)
    {
      UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];

        if (i<1)
        {
            [btn setFrame:CGRectMake(0, 0, 39, 39)];
            [btn setImage:[UIImage imageNamed:@"addcategory_up.png"] forState:UIControlStateNormal];
            [btn setImage:[UIImage imageNamed:@"addcategory_down.png"] forState:UIControlStateHighlighted];

            x = x + btn.frame.size.width+10; y=y+btn.frame.origin.y;
            [btn setTitle:titleString forState: UIControlStateNormal];

            [btn setTag:i];

        }
       else
       {
        titleString = [titleString stringByAppendingString:[NSString stringWithFormat:@"%d",i]]; // get button title

        CGSize fontSize = [titleString sizeWithFont:[UIFont systemFontOfSize:12.0]];
        CGRect currentFrame = btn.frame;

        CGRect buttonFrame = CGRectMake(x, y, fontSize.width + 22.0, 40);

        if ((buttonFrame.origin.x+buttonFrame.size.width) >_subADCView.frame.size.width)
        {
            x=0;y=_subADCView.frame.size.height;

            _subADCView.frame=CGRectMake(_subADCView.frame.origin.x, _subADCView.frame.origin.y, _subADCView.frame.size.width, _subADCView.frame.size.height+frameHeight);
             buttonFrame = CGRectMake(x, y, fontSize.width+ 22.0, 40);

        }

        x = x + fontSize.width + 35.0; y=y+currentFrame.origin.y;
        [btn setFrame:buttonFrame];

//I need to set the button image here
      [btn setImage:[[UIImage imageNamed:@"edit_category_middle_up.png"] stretchableImageWithLeftCapWidth:10 topCapHeight:0] forState:UIControlStateNormal];
      [btn setImage:[[UIImage imageNamed:@"edit_category_middle_down.png"] stretchableImageWithLeftCapWidth:10 topCapHeight:0] forState:UIControlStateHighlighted];

            [btn setTitle:titleString forState: UIControlStateNormal];

            [btn setTag:i];
            lastButtonPosition=btn.frame.origin.y+btn.frame.size.height;
           }
            [self.subADCView addSubview:btn];

        }
         [self readjustSubviews];
    }

Answer 1

如果您使用以下技术，则只需要单个图像中的背景。

UIImage *backgroundImage = [[UIImage imageNamed:@"MyImageTitle"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, leftInset, 0, rightInset)];

其中 leftInset 是图像左侧不可拉伸(stretch)内容的宽度，rightInset 是图像右侧不可拉伸(stretch)内容的宽度。

这将创建一个仅在定义的插图内拉伸(stretch)内容的图像。这是解决这个问题的最好方法。

或者，如果您无法组合图像，那么您可以这样做。

UIImage *leftImage = [UIImage imageNamed:@"edit_category_left_up"];
UIImage *middleImage = [UIImage imageNamed:@"edit_category_middle_up"];
UIImage *rightImage = [UIImage imageNamed:@"edit_category_right_up"];

UIImageView *leftImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, leftImage.size.width, btn.frame.size.height)];
[leftImageView setImage:leftImage];

UIImageView *middleImageView = [[UIImageView alloc] initWithFrame:CGRectMake(leftImageView.frame.size.width, 0, btn.frame.size.width - (leftImage.size.width + rightImage.size.width), btn.frame.size.height)];
[middleImageView setImage:middleImage];

UIImageView *rightImageView = [[UIImageView alloc] initWithFrame:CGRectMake(middleImageView.frame.origin.x + middleImageView.frame.size.width, 0, rightImage.size.width, btn.frame.size.height)];
[rightImageView setImage:rightImage];

[btn addSubview:leftImageView];
[btn addSubview:middleImageView];
[btn addSubview:rightImageView];

您可能需要尝试插入 subview 的图层。为此，您可以使用以下方法之一:

[btn insertSubview:view aboveSubview:otherView];

[btn insertSubview:view atIndex:someIndex];

[btn insertSubview:view belowSubview:otherView];