如何为具有动态宽度的 UIButtons 设置背景？答案

【问题标题】：How to set background for UIButtons with dynamic width?如何为具有动态宽度的 UIButtons 设置背景？
【发布时间】：2013-12-02 07:50:06
【问题描述】：

我有 3 个按钮图像，分别命名为 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];
    }

【问题讨论】：

类似这个1..stackoverflow.com/questions/12002908/…
方法 stretchableImageWithLeftCapWidth:topCapHeight: 已弃用。使用 resizableImageWithCapInsets: 代替，指定 cap insets 使得内部是 1x1 区域。

标签： ios iphone objective-c uibutton uiimage

【解决方案1】：

如果您使用以下技术，您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 是图片左侧不可拉伸内容的宽度，rightInset 是图片右侧不可拉伸内容的宽度。

这将创建一个仅在定义的插图内拉伸内容的图像。这是解决此问题的最佳方法。

或者，如果您无法合并图像，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];

您可能需要使用插入子视图的层。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];

【讨论】：

【解决方案2】：

试试这段代码合并三张图片

-(UIImage*)combineImages
{
    UIImage *image1 = [UIImage imageNamed:@"test.png"];
    UIImage *image2 = [UIImage imageNamed:@"yyu.png"];
    UIImage *image3=[UIImage imageNamed:@"test.png"];
    //self.imageView.image=image3;
    CGSize size = CGSizeMake(image1.size.width+image2.size.width+image3.size.width, image1.size.height );

    UIGraphicsBeginImageContext(size);

    [image1 drawInRect:CGRectMake(0,0,image1.size.width, size.height)];
    [image2 drawInRect:CGRectMake(image1.size.width,0,image2.size.width, size.height)];
    [image3 drawInRect:CGRectMake(image1.size.width+image2.size.width, 0,image3.size.width,size.height)];

    UIImage *finalImage =UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return finalImage;

}

【讨论】：

【解决方案3】：

你是只为 iOS7 写的吗？

如果是这样，制作一个“可拉伸”图像并使用资产目录将其导入项目中。

然后，您可以在此处指定目录中可拉伸图像的属性（即帽插图等...）。

然后要正确设置背景图像，您只需使用...

[button setBackgroundImage:[UIImage imageNamed:@"BackgroundImage"] forState:UIControlStateNormal];

这将从资产目录中获取可调整大小/可拉伸的属性。

【讨论】：

【解决方案4】：

只需查看此线程一次。可能这不适合您正在寻找的东西，但我希望它可能对您或其他人有所帮助。

Build a UIImage with multiple stretchable images

【讨论】：