const time = new Date()
时间: 2023-11-17 20:37:18 浏览: 41
这行代码也是 JavaScript 代码,它的作用是创建一个 Date 对象并将其赋值给变量 time。这个 Date 对象表示的是当前的日期和时间,可以通过调用它的各种方法来获取具体的年、月、日、时、分、秒等信息。如果将这个变量直接输出,会得到一个表示时间的字符串,例如:"Fri Aug 20 2021 14:30:00 GMT+0800 (中国标准时间)"。需要注意的是,这个时间是根据服务器所在的时区来显示的。
相关问题
<script setup> import useGetUrl from "@/hooks/useGetUrl"; import { reactive ,onMounted} from "vue"; const state = reactive({ inputText: "", isKeyboardVisible: false, messages: [ { content: "施主你好,很高兴为您服务!", msg: { time:"" } }, ], sendMessage: () => { const content = state.inputText.trim(); if (content) { const time = new Date(); const message = { id: state.messages.length + 1, content, time, isUser: true, }; state.messages.push(message); state.inputText = ""; state.replyMessage(); } }, replyMessage: () => { const content = "尊敬的施主,您好。我们已收到您的咨询,请稍后。"; const time = new Date(); const message = { id: state.messages.length + 1, content, time, isUser: false, }; setTimeout(() => { state.messages.push(message); }, 1000); }, formatDate: (time) => { const date = time?new Date(time):new Date(); const hours = date.getHours().toString().padStart(2, "0"); const minutes = date.getMinutes().toString().padStart(2, "0"); return ${hours}:${minutes}; }, showKeyboard() { state.isKeyboardVisible = true; document.querySelector("input").focus(); }, hideKeyboard() { state.isKeyboardVisible = false; document.activeElement.focus(); }, // handleScroll() { // const chatList = this.$refs.chatList; // const scrollTop = chatList.scrollTop; // const scrollHeight = chatList.scrollHeight; // const clientHeight = chatList.clientHeight; // if (scrollTop === 0) { // // 聊天列表滚动到了顶部,需要加载更多聊天记录 // // TODO: 加载更多聊天记录 // // 滚动到之前的位置,避免列表跳动 // chatList.scrollTop = chatList.scrollHeight - scrollHeight; // } else if (scrollTop + clientHeight >= scrollHeight) { // // 聊天列表滚动到了底部,需要将列表自动上滑 // chatList.scrollTop = chatList.scrollHeight - clientHeight; // } // }, }); onMounted(() => { state.messages[0].msg.time = state.formatDate() }) </script>在该段代码中增加列表置底后上滑
可以在聊天列表上添加一个ref属性,用于获取聊天列表的dom节点,然后在sendMessage和replyMessage方法中,将聊天列表的scrollTop设置为聊天列表的scrollHeight,实现自动置底。在handleScroll方法中,可以判断scrollTop是否为0,如果为0则说明聊天列表已经滚动到了顶部,可以加载更多聊天记录;如果scrollTop加上clientHeight大于等于scrollHeight,则说明聊天列表已经滚动到了底部,需要将列表自动上滑。以下是修改后的代码:
```
<template>
<div class="chat-container">
<div class="chat-header">在线客服</div>
<div class="chat-list" ref="chatList">
<div class="chat-message" v-for="message in state.messages" :key="message.id">
<div class="chat-content" :class="{'user': message.isUser}">
<div class="chat-text">{{ message.content }}</div>
<div class="chat-time">{{ state.formatDate(message.time) }}</div>
</div>
</div>
</div>
<div class="chat-input">
<div class="chat-input-box" :class="{'show-keyboard': state.isKeyboardVisible}">
<input type="text" v-model="state.inputText" placeholder="请输入您的问题" />
<div class="chat-input-btn" @click="state.sendMessage">发送</div>
<div class="chat-input-keyboard" @click="state.showKeyboard">键盘</div>
<div class="chat-input-voice">语音</div>
</div>
<div class="chat-input-keyboard-box" v-show="state.isKeyboardVisible">
<div class="chat-input-keyboard-item" v-for="(item, index) in state.keyboard" :key="index" @click="state.inputText += item">{{ item }}</div>
<div class="chat-input-keyboard-item" @click="state.inputText = state.inputText.slice(0, -1)">删除</div>
<div class="chat-input-keyboard-item" @click="state.hideKeyboard">收起</div>
</div>
</div>
</div>
</template>
<script setup>
import { reactive, onMounted } from "vue";
import useGetUrl from "@/hooks/useGetUrl";
const state = reactive({
inputText: "",
isKeyboardVisible: false,
messages: [
{
content: "施主你好,很高兴为您服务!",
time: new Date(),
isUser: false,
},
],
keyboard: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "0"],
sendMessage: () => {
const content = state.inputText.trim();
if (content) {
const time = new Date();
const message = {
id: state.messages.length + 1,
content,
time,
isUser: true,
};
state.messages.push(message);
state.inputText = "";
state.replyMessage();
state.scrollToBottom();
}
},
replyMessage: () => {
const content = "尊敬的施主,您好。我们已收到您的咨询,请稍后。";
const time = new Date();
const message = {
id: state.messages.length + 1,
content,
time,
isUser: false,
};
setTimeout(() => {
state.messages.push(message);
state.scrollToBottom();
}, 1000);
},
formatDate: (time) => {
const date = time ? new Date(time) : new Date();
const hours = date.getHours().toString().padStart(2, "0");
const minutes = date.getMinutes().toString().padStart(2, "0");
return `${hours}:${minutes}`;
},
showKeyboard() {
state.isKeyboardVisible = true;
document.querySelector("input").focus();
},
hideKeyboard() {
state.isKeyboardVisible = false;
document.activeElement.focus();
},
scrollToBottom() {
const chatList = this.$refs.chatList;
chatList.scrollTop = chatList.scrollHeight;
},
});
onMounted(() => {
state.messages[0].time = state.formatDate();
});
</script>
<style scoped>
.chat-container {
width: 100%;
height: 100%;
display: flex;
flex-direction: column;
}
.chat-header {
height: 40px;
line-height: 40px;
background-color: #f5f5f5;
text-align: center;
}
.chat-list {
flex: 1;
overflow-y: auto;
padding: 10px;
}
.chat-message {
margin-bottom: 10px;
}
.chat-content {
display: inline-block;
padding: 5px 10px;
border-radius: 10px;
max-width: 80%;
word-wrap: break-word;
}
.chat-content.user {
text-align: right;
background-color: #e6f7ff;
}
.chat-content.user .chat-text {
display: inline-block;
text-align: left;
}
.chat-content:not(.user) {
text-align: left;
background-color: #fff;
}
.chat-time {
font-size: 12px;
color: #999;
text-align: right;
margin-top: 5px;
}
.chat-input {
height: 50px;
border-top: 1px solid #ddd;
display: flex;
align-items: center;
justify-content: center;
position: relative;
}
.chat-input-box {
width: 100%;
display: flex;
align-items: center;
justify-content: center;
position: absolute;
bottom: 0;
left: 0;
padding: 5px;
}
.chat-input-btn {
background-color: #409eff;
color: #fff;
padding: 5px 10px;
border-radius: 5px;
margin-left: 10px;
cursor: pointer;
}
.chat-input-keyboard {
font-size: 20px;
margin-left: 10px;
cursor: pointer;
}
.chat-input-voice {
font-size: 20px;
margin-left: 10px;
cursor: pointer;
}
.chat-input-keyboard-box {
width: 100%;
display: none;
position: absolute;
bottom: 50px;
left: 0;
background-color: #fff;
border-top: 1px solid #ddd;
}
.chat-input-keyboard-box.show {
display: block;
}
.chat-input-keyboard-item {
display: inline-block;
width: calc(100% / 3);
height: 40px;
line-height: 40px;
text-align: center;
cursor: pointer;
}
.chat-input-keyboard-item:nth-child(10) {
width: calc(100% / 3 * 2);
}
.show-keyboard .chat-input-keyboard-box {
display: block;
}
</style>
```
async function getServerTime() { console.log('获取时间'); const now = Date.now(); const cacheServerTimeTime = app.globalData.servertimetime || 0; const cacheServerTime = app.globalData.servertime || null; const date = new Date() const y = date.getFullYear() const m = date.getMonth() + 1 const d = date.getDate() const systemToday = y + '-' + (m < 10 ? '0' + m : m) + '-' + (d < 10 ? '0' + d : d) if (cacheServerTime && now - cacheServerTimeTime < 5 * 60 * 1000 && systemToday === cacheServerTime) { console.log('缓存servertime未过期,返回缓存servertime'); return cacheServerTime; } else { console.log('缓存servertime过期,重新获取服务器时间'); const today = await wx.cloud.callFunction({name: 'getServerTime'}); app.globalData.servertime = today.result; app.globalData.servertimetime = Date.now(); return today.result; } }这段代码在微信小程序中存在那些问题?你能指出问题,并修复问题吗?
这段代码存在以下问题:
1. 缺少`app`对象的定义,需要在代码中定义或者引入。
2. `wx.cloud.callFunction`是一个异步函数,在调用时需要使用`await`关键字。
3. 在判断缓存是否过期时,应该先判断缓存是否存在,否则会出现未定义错误。
修复后的代码如下:
```
async function getServerTime() {
const app = getApp();
console.log('获取时间');
const now = Date.now();
const cacheServerTimeTime = app.globalData.servertimetime || 0;
const cacheServerTime = app.globalData.servertime || null;
const date = new Date();
const y = date.getFullYear();
const m = date.getMonth() + 1;
const d = date.getDate();
const systemToday = y + '-' + (m < 10 ? '0' + m : m) + '-' + (d < 10 ? '0' + d : d);
if (cacheServerTime && now - cacheServerTimeTime < 5 * 60 * 1000 && systemToday === cacheServerTime) {
console.log('缓存servertime未过期,返回缓存servertime');
return cacheServerTime;
} else {
console.log('缓存servertime过期,重新获取服务器时间');
const { result } = await wx.cloud.callFunction({name: 'getServerTime'});
app.globalData.servertime = result;
app.globalData.servertimetime = Date.now();
return result;
}
}
```