如何使带有类消息的 div 元素可滚动？溢出：自动不显示滚动条，div 无法滚动

Question

正如您在下面的代码中看到的，我有一个messages类的div元素，它包含许多message类的子div元素。每当这个div里面的messagediv太多时，我就试图让它可以滚动。问题是overflow: auto;没有显示滚动条，并且由于某些原因div无法滚动。

我不确定这是否相关，但messagesdiv的父级高度为100vh，而messagesdiv占用flex: 1空间。

*, *:after, *:before {
margin: 0;
padding: 0;
-webkit-box-sizing: border-box;
box-sizing: border-box;
text-decoration: none;
list-style-type: none;
}
.chat {
flex: 1;
display: flex;
flex-direction: column;
background-color: #36393f;
height: 100vh;
}
.chat-container {
display: flex;
flex-direction: column;
height: 100%;
}
.selected-room-name {
padding: 20px;
color: #ffffff;
font-weight: 500;
font-size: 16px;
border-bottom: 2px solid rgba(0, 0, 0, 0.2);
}
.messages {
display: flex;
flex-direction: column;
justify-content: flex-end;
flex: 1;
padding: 20px;
overflow: auto;
}
.message {
display: flex;
align-items: center;
background-color: #40444b;
padding: 15px;
border-radius: 10px;
margin-bottom: 20px;
color: #e0e0e0;
height: 50px;
}
.message:last-child {
margin-bottom: 0px;
}
.form-container {
display: flex;
justify-content: center;
align-items: center;
}
.send-message {
padding: 20px 0px 20px 20px;
flex: 1;
}
.message-input {
width: 100%;
padding: 15px;
outline: none;
border: none;
background-color: #40444b;
color: #dcddde;
font-size: 14px;
border-radius: 5px 0 0 5px;
}

<div class="chat">
<div class='chat-container'>
<p class='selected-room-name'>Server</p>
<div class="messages">
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
</div>
<div class="form-container">
<form class='send-message' >
<input class='message-input'  placeholder="Type a message">
</form>
</div>
</div>
</div>

Answer 1

在css中，您需要.messages{}上的overflow: overflow-y;。我还在房间名称上给了你一个免费的position: sticky;：(

*, *:after, *:before {
margin: 0;
padding: 0;
-webkit-box-sizing: border-box;
box-sizing: border-box;
text-decoration: none;
list-style-type: none;
}
.chat {
flex: 1;
display: flex;
flex-direction: column;
height: 100vh;
}
.chat-container {
position: relative;
display: flex;
flex-direction: column;
height: 100%;
}
.selected-room-name {
position: sticky;
top: 0px;
padding: 20px;
color: #ffffff;
font-weight: 500;
font-size: 16px;
border-bottom: 2px solid rgba(0, 0, 0, 0.2);
max-height:100%;
}
.messages {
display: flex;
flex-direction: column;
justify-content: flex-end;
flex: 1;
padding: 20px;
overflow: overflow-y;

}
.message {
display: flex;
align-items: center;
background-color: #40444b;
padding: 15px;
border-radius: 10px;
margin-bottom: 20px;
color: #e0e0e0;
height: 50px;
}
.message:last-child {
margin-bottom: 0px;
}
.form-container {
display: flex;
justify-content: center;
align-items: center;
}
.send-message {
padding: 20px 0px 20px 20px;
flex: 1;
}
.message-input {
width: 100%;
padding: 15px;
outline: none;
border: none;
background-color: #40444b;
color: #dcddde;
font-size: 14px;
border-radius: 5px 0 0 5px;
}

<div class="chat">
<div class='chat-container'>
<p class='selected-room-name'>Server</p>
<div class="messages">
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
<div class='message'></div>
</div>
<div class="form-container">
<form class='send-message' >
<input class='message-input'  placeholder="Type a message">
</form>
</div>
</div>
</div>