我正在使用React Native(聊天),在这个应用程序中,我有一个表情符号选择器,但是当用户按下虚拟退格按钮时,表情符号只会删除其最后一个unicode字节。
如何确定最后一个“聊天”(一组unicode)是否是独立的表情符号unicode? p>
将其拆分的代码:
inputValue.substring(0, inputValue.length - 1)
我还尝试使用Array.from(),然后使用slice(0,-1)并在控制台记录日志时出现针对所有情况的正确解决方案。但!当我将SAME变量设置为TextInput时出现:321331231221。
一些例子:
"Hello".length
7
"Hello".slice(0,-1)
'Hello�'
Array.from("Hello")
[ 'H', 'e', 'l', 'l', 'o', '' ]
Array.from("Hello").slice(0,-1)
[ 'H', 'e', 'l', 'l', 'o' ]
Array.from("Hello").slice(0,-1).join('')
'Hello'
但是,如果我在React Native TextInput组件中设置了最后一个解决方案,则会看到类似以下内容的内容:312412412411(可能全部为十六进制)。如果该值没有表情符号,我也会看到相同的结果。
当我使用表情符号选择器设置表情符号时,${inputValue}${newEmoji}
之类的东西都可以解决。
我不知道该怎么想:/
答案 0 :(得分:1)
尝试切片:
/**
* Directory where uploaded files will be saved, its relative to
* the web application directory.
*/
private static final String UPLOAD_DIR = "uploads";
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
// gets absolute path of the web application
String applicationPath = request.getServletContext().getRealPath("");
// constructs path of the directory to save uploaded file
String uploadFilePath = applicationPath + File.separator + UPLOAD_DIR;
// creates the save directory if it does not exists
File fileSaveDir = new File(uploadFilePath);
if (!fileSaveDir.exists()) {
fileSaveDir.mkdirs();
}
System.out.println("Upload File Directory="+fileSaveDir.getAbsolutePath());
String fileName = null;
//Get all the parts from request and write it to the file on server
for (Part part : request.getParts()) {
fileName = getFileName(part);
part.write(uploadFilePath + File.separator + fileName);
}
request.setAttribute("message", fileName + " File uploaded successfully!");
getServletContext().getRequestDispatcher("/response.jsp").forward(
request, response);
}
/**
* Utility method to get file name from HTTP header content-disposition
*/
private String getFileName(Part part) {
String contentDisp = part.getHeader("content-disposition");
System.out.println("content-disposition header= "+contentDisp);
String[] tokens = contentDisp.split(";");
for (String token : tokens) {
if (token.trim().startsWith("filename")) {
return token.substring(token.indexOf("=") + 2, token.length()-1);
}
}
return "";
}
更新:
此软件包可能会帮助您:runes
您的需求示例:
inputValue.slice(0, -1);