正则查出范围---根据文字字符串创建imge--创建属性字符串(带图片的atachment)---属性字符串替换原来的表情根据位置

进入房间--离开房间---名字变色

class func GenerateEnterOrLeaveRoom(_ isEnter : Bool, _ username : String) -> NSAttributedString {

// coderwhy 进入房间

// 1.拼接完整的消息

let message = username + (isEnter ? " 进入房间" : " 离开房间")

// 2.根据String创建NSMutableAttributedString

let attrMessage = NSMutableAttributedString(string: message)

// 3.修改名字的颜色

let nameRange = NSRange(location: 0, length: username.lengthOfBytes(using: .utf8))

attrMessage.setAttributes([NSForegroundColorAttributeName : UIColor.orange], range: nameRange)

return attrMessage

}

聊天消息---带图片

步骤:正则匹配[]-->匹配出数组--->遍历数组-->取出图片字符串位置--创建图片---替换字符串中的位置

class func generateChatMessage(_ username : String, _ message : String, _ font : UIFont) -> NSAttributedString {

// 1.拼接完整的消息

let chatMessage = username + ":" + message

// 2.根据string创建NSMutableAttributedString

let chatAttrString = NSMutableAttributedString(string: chatMessage)

// 3.将名字改成特殊的颜色

let nameRange = NSRange(location: 0, length: username.lengthOfBytes(using: .utf8))

chatAttrString.setAttributes([NSForegroundColorAttributeName : UIColor.orange], range: nameRange)

// 4.I [哈哈] my [嘿嘿]is [嘻嘻]why[呵呵]

// [哈哈] --> 图片名称 --> UIImage --> NSTextAttachment -> NSAttributedString

// 4.1.使用正则表达式, 将表情对应的文字匹配出来  [1379]

let pattern = "\\[.*?\\]"      .去除特殊字符  * 数量不同  ?遇到第一个就截止

guard let regex = try? NSRegularExpression(pattern: pattern, options: .caseInsensitive) else {

return chatAttrString

}

// 4.2.匹配结果

let range = NSRange(location: 0, length: chatMessage.characters.count)

let results = regex.matches(in: chatMessage, options: [], range: range)

// 4.3.遍历所有的结果---反转遍历--证遍历range就不对了--文字替换成表情字符数不同

for i in (0..<results.count).reversed() {

// 4.4.获取result对应的问题

let result = results[i]

let imageName = (chatMessage as NSString).substring(with: result.range)

// 4.5.根据imageName创建对应的UIImage对象

guard let image = UIImage(named: imageName) else {

continue

}

// 4.6.根据图片创建NSTextAttachment

let attachment = NSTextAttachment()

attachment.image = image

attachment.bounds = CGRect(x: 0, y: -4, width: font.lineHeight, height: font.lineHeight)

// 4.7.根据NSTextAttachment创建NSAttributedString

let imageAttrStr = NSAttributedString(attachment: attachment)

// 4.8.将之前的文字, 替换成当前imageAttrStr

chatAttrString.replaceCharacters(in: result.range, with: imageAttrStr)

}

return chatAttrString

}

送礼物 图文混排

class func generateGiftMessage(_ username : String, _ giftName : String, _ giftURL : String) -> NSAttributedString {

// 1.拼接完整的字符串

let giftMessage = username + " 赠送给主播 " + giftName

// 2.根据String创建NSMutableAttributedString

let giftAttrString = NSMutableAttributedString(string: giftMessage)

// 3.设置名字的颜色

let nameRange = NSRange(location: 0, length: username.lengthOfBytes(using: .utf8))

giftAttrString.setAttributes([NSForegroundColorAttributeName : UIColor.orange], range: nameRange)

// 4.将礼物的名称修改成特殊颜色

let giftNameRange = (giftMessage as NSString).range(of: giftName)

giftAttrString.setAttributes([NSForegroundColorAttributeName : UIColor.red], range: giftNameRange)

// 5.根据giftURL创建UIImage对象

guard let image = KingfisherManager.shared.cache.retrieveImageInMemoryCache(forKey: giftURL) else {

return giftAttrString

}

// 6.创建NSTextAttachment

let giftImageAttr = AttributeStrGenerator.getAttrStringWithImage(image, UIFont.systemFont(ofSize: 17.0))

// 7.将giftImageAttr拼接到giftAttrString

giftAttrString.append(giftImageAttr)

return giftAttrString

}

private class func getAttrStringWithImage(_ image : UIImage, _ font : UIFont) -> NSAttributedString {

let attachment = NSTextAttachment()

attachment.image = image

attachment.bounds = CGRect(x: 0, y: -4, width: font.lineHeight, height: font.lineHeight)

return NSAttributedString(attachment: attachment)

}