Ionic3 error 'ion-header' is not a known element:

using ionic, I want to write a tab switch, which can be regarded as secondary navigation. I got a component and wrote
< ion-header >

.

< ion-navbar >

<button ion-button icon-only menuToggle>
  <ion-icon name="menu"></ion-icon>
</button>

<ion-title>
  Page Title
</ion-title>

< / ion-navbar >

< / ion-header >
copy it directly on the Internet, and then you will see the error

.

clipboard.png

clipboard.png

clipboard.png
it"s been a day. I don"t know what went wrong. What plug-ins are missing? Or what"s the problem? Ask God to take a look, thank you!


try npm ion-icon. If you haven't used ion-icon


ng4, just replace it with ng5,

.
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e43cb3-26f9e.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e43cb3-26f9e.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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