小编Kus*_*wal的帖子

我的公司有一项任务，我必须显示用户名是否被占用，我使用 formik 和 yup 验证进行检查，所以暂时我在 yup 验证中添加了一个自定义测试功能，该功能显示用户名是否被使用单击提交按钮是否被采用，但是，我最初的任务是在用户输入用户名时动态显示错误消息，它应该告诉他用户名是否被采用。\n我明白我可能必须操作formik的默认handleChange，但我\xe2\x80\x99m无法这样做。\n非常感谢任何帮助！

         validationSchema: Yup.object({\n            name: Yup.string()\n                .min(2, "Mininum 2 characters")\n                .max(30, "Maximum 30 characters")\n                .required("Your name is required"),\n            email: Yup.string()\n                .email("Invalid email format")\n                .test("email", "This email has already been registered", function (email) {\n                        return checkAvailabilityEmail(email);\n                })\n                .required("Your email is required"),\n            username: Yup.string()\n                .min(1, "Mininum 1 characters")\n                .max(15, "Maximum 15 characters")\n                .test("username", "This username has already been taken", function (username) {\n                        return checkAvailabilityUsername(username);\n                })\n                .required("You must enter a username"),\n