iOS 7 TextKit - 如何插入与文本内联的图像？

Question

我正在尝试使用 UITextView 获得以下效果：

基本上我想在文本之间插入图像。图像只需占用 1 行空间，因此无需换行。

我尝试在子视图中添加一个 UIView：

UIView *pictureView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 25, 25)];
[pictureView setBackgroundColor:[UIColor redColor]];
[self.textView addSubview:pictureView];

但它似乎漂浮在文本上并覆盖它。

我对排除路径做了一些阅读，这似乎是实现这一点的一种方式。但是，我不想绝对定位图像 - 相反，它应该与文本一起流动（类似于 <span> 在 HTML 中的行为方式）。

Answer 1

您可以尝试使用 NSAttributedString 和 NSTextAttachment。查看以下链接，了解有关自定义 NSTextAttachment 以调整图像大小的更多详细信息。 http://ossh.com.au/design-and-technology/software-development/implementing-rich-text-with-images-on-os-x-and-ios/

在我的示例中，我调整了图像的大小以适应宽度，在您的情况下，您可能希望调整图像的大小以匹配行高。

Answer 2

您需要使用属性字符串并将图像添加为NSTextAttachment 的实例：

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:@"like after"];

NSTextAttachment *textAttachment = [[NSTextAttachment alloc] init];
textAttachment.image = [UIImage imageNamed:@"whatever.png"];

NSAttributedString *attrStringWithImage = [NSAttributedString attributedStringWithAttachment:textAttachment];

[attributedString replaceCharactersInRange:NSMakeRange(4, 1) withAttributedString:attrStringWithImage];

Answer 3

@bilobatum 的代码转换为 Swift 供有需要的人使用：

let attributedString = NSMutableAttributedString(string: "like after")

let textAttachment = NSTextAttachment()

textAttachment.image = UIImage(named: "whatever.png")

let attrStringWithImage = NSAttributedString(attachment: textAttachment)

attributedString.replaceCharacters(in: NSMakeRange(4, 1), with: attrStringWithImage)

Answer 4

扩展@bilobatum 的answer，并使用另一个问题的this category。我做了这个：

用法：

UILabel *labelWithImage = [UILabel new];
labelWithImage.text = @"Tap [new-button] to make a new thing!";
NSAttributedString *stringWithImage = [labelWithImage.attributedText attributedStringByReplacingOccurancesOfString:@"[new-button]" withImage:[UIImage imageNamed:@"MyNewThingButtonImage"] scale:0];
labelWithImage.attributedText = stringWithImage;

实施：

@interface NSMutableAttributedString (InlineImage)

- (void)replaceCharactersInRange:(NSRange)range withInlineImage:(UIImage *)inlineImage scale:(CGFloat)inlineImageScale;

@end

@interface NSAttributedString (InlineImages)

- (NSAttributedString *)attributedStringByReplacingOccurancesOfString:(NSString *)string withInlineImage:(UIImage *)inlineImage scale:(CGFloat)inlineImageScale;

@end

.

@implementation NSMutableAttributedString (InlineImages)

- (void)replaceCharactersInRange:(NSRange)range withInlineImage:(UIImage *)inlineImage scale:(CGFloat)inlineImageScale {

    if (floorf(inlineImageScale) == 0)
        inlineImageScale = 1.0f;

    // Create resized, tinted image matching font size and (text) color
    UIImage *imageMatchingFont = [inlineImage imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
    {
        // Font size
        NSDictionary *attributesForRange = [self attributesAtIndex:range.location effectiveRange:nil];
        UIFont *fontForRange = [attributesForRange valueForKey:NSFontAttributeName];
        CGSize imageSizeMatchingFontSize = CGSizeMake(inlineImage.size.width * (fontForRange.capHeight / inlineImage.size.height), fontForRange.capHeight);

        // Some scaling for prettiness
        CGFloat defaultScale = 1.4f;
        imageSizeMatchingFontSize = CGSizeMake(imageSizeMatchingFontSize.width * defaultScale,     imageSizeMatchingFontSize.height * defaultScale);
        imageSizeMatchingFontSize = CGSizeMake(imageSizeMatchingFontSize.width * inlineImageScale, imageSizeMatchingFontSize.height * inlineImageScale);
        imageSizeMatchingFontSize = CGSizeMake(ceilf(imageSizeMatchingFontSize.width), ceilf(imageSizeMatchingFontSize.height));

        // Text color
        UIColor *textColorForRange = [attributesForRange valueForKey:NSForegroundColorAttributeName];

        // Make the matching image
        UIGraphicsBeginImageContextWithOptions(imageSizeMatchingFontSize, NO, 0.0f);
        [textColorForRange set];
        [inlineImage drawInRect:CGRectMake(0 , 0, imageSizeMatchingFontSize.width, imageSizeMatchingFontSize.height)];
        imageMatchingFont = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }

    // Text attachment with image
    NSTextAttachment *textAttachment = [NSTextAttachment new];
    textAttachment.image = imageMatchingFont;
    NSAttributedString *imageString = [NSAttributedString attributedStringWithAttachment:textAttachment];

    [self replaceCharactersInRange:range withAttributedString:imageString];
}

@end

@implementation NSAttributedString (InlineImages)

- (NSAttributedString *)attributedStringByReplacingOccurancesOfString:(NSString *)string withInlineImage:(UIImage *)inlineImage scale:(CGFloat)inlineImageScale {

    NSMutableAttributedString *attributedStringWithImages = [self mutableCopy];

    [attributedStringWithImages.string enumerateOccurancesOfString:string usingBlock:^(NSRange substringRange, BOOL *stop) {
        [attributedStringWithImages replaceCharactersInRange:substringRange withInlineImage:inlineImage scale:inlineImageScale];

    }];

    return [attributedStringWithImages copy];
}

@end

Answer 5

简单示例中的问题解决方案是

let attachment = NSTextAttachment()
attachment.image = UIImage(named: "qrcode")

let iconString = NSAttributedString(attachment: attachment)
let firstString = NSMutableAttributedString(string: "scan the ")
let secondString = NSAttributedString(string: "QR code received on your phone.")

firstString.append(iconString)
firstString.append(secondString)

self.textLabel.attributedText = firstString