Question

Ionic4项目中我们可以使用Ionic4组件ion-textarea对项目进行布局。

ion-textarea官方文档地址:https://ionicframework.com/docs/api/textarea

The textarea component is used for multi-line text input. A native textarea element is rendered inside of the component. The user experience and interactivity of the textarea component is improved by having control over the native textarea.

Unlike the native textarea element, the Ionic textarea does not support loading its value from the inner content. The textarea value should be set in the value attribute.

The textarea component accepts the native textarea attributes in addition to the Ionic properties.

ion-textarea　用法(Usage)

angularjavascriptreactvue

  




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</ion-item>

  




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</ion-item>

import React from 'react';

import { IonTextarea, IonItem, IonLabel } from '@ionic/react';

const Example: React.SFC = () => (
  
    {/*-- Default textarea --*/}
    

    {/*-- Textarea in an item with a placeholder --*/}
    
      
    

    {/*-- Textarea in an item with a floating label --*/}
    
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    {/*-- Disabled and readonly textarea in an item with a stacked label --*/}
    
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    {/*-- Textarea that clears the value on edit --*/}
    
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    {/*-- Textarea with custom number of rows and cols --*/}
    
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);

export default Example;

  
  

  
  
    
  

  
  
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</template>

ion-textarea　属性(Properties)

autoGrow
Description	If true, the element height will increase based on the value.
Attribute	auto-grow
Type	boolean
Default	false
autocapitalize
Description	Indicates whether and how the text value should be automatically capitalized as it is entered/edited by the user.
Attribute	autocapitalize
Type	string
Default	'none'
autofocus
Description	This Boolean attribute lets you specify that a form control should have input focus when the page loads.
Attribute	autofocus
Type	boolean
Default	false
clearOnEdit
Description	If true, the value will be cleared after focus upon edit. Defaults to true when type is "password", false for all other types.
Attribute	clear-on-edit
Type	boolean
Default	false
color
Description	The color to use from your application's color palette. Default options are: "primary", "secondary", "tertiary", "success", "warning", "danger", "light", "medium", and "dark". For more information on colors, see theming.
Attribute	color
Type	string | undefined
cols
Description	The visible width of the text control, in average character widths. If it is specified, it must be a positive integer.
Attribute	cols
Type	number | undefined
debounce
Description	Set the amount of time, in milliseconds, to wait to trigger the ionChange event after each keystroke.
Attribute	debounce
Type	number
Default	0
disabled
Description	If true, the user cannot interact with the textarea.
Attribute	disabled
Type	boolean
Default	false
maxlength
Description	If the value of the type attribute is text, email, search, password, tel, or url, this attribute specifies the maximum number of characters that the user can enter.
Attribute	maxlength
Type	number | undefined
minlength
Description	If the value of the type attribute is text, email, search, password, tel, or url, this attribute specifies the minimum number of characters that the user can enter.
Attribute	minlength
Type	number | undefined
mode
Description	The mode determines which platform styles to use.
Attribute	mode
Type	"ios" | "md"
name
Description	The name of the control, which is submitted with the form data.
Attribute	name
Type	string
Default	this.inputId
placeholder
Description	Instructional text that shows before the input has a value.
Attribute	placeholder
Type	null | string | undefined
readonly
Description	If true, the user cannot modify the value.
Attribute	readonly
Type	boolean
Default	false
required
Description	If true, the user must fill in a value before submitting a form.
Attribute	required
Type	boolean
Default	false
rows
Description	The number of visible text lines for the control.
Attribute	rows
Type	number | undefined
spellcheck
Description	If true, the element will have its spelling and grammar checked.
Attribute	spellcheck
Type	boolean
Default	false
value
Description	The value of the textarea.
Attribute	value
Type	null | string | undefined
Default	''
wrap
Description	Indicates how the control wraps text.
Attribute	wrap
Type	"hard" | "off" | "soft" | undefined

ion-textarea　事件(Events)

Name	Description
ionBlur	Emitted when the input loses focus.
ionChange	Emitted when the input value has changed.
ionFocus	Emitted when the input has focus.
ionInput	Emitted when a keyboard input ocurred.

ion-textarea　内置方法(Methods)

getInputElement
Description	Returns the native <textarea> element used under the hood.
Signature	getInputElement() => Promise<HTMLTextAreaElement>
setFocus
Description	Sets focus on the specified ion-textarea. Use this method instead of the global input.focus().
Signature	setFocus() => void

ion-textarea中的CSS 自定义属性

Name	Description
--background	Background of the textarea
--border-radius	Border radius of the textarea
--color	Color of the text
--padding-bottom	Bottom padding of the textarea
--padding-end	End padding of the textarea
--padding-start	Start padding of the textarea
--padding-top	Top padding of the textarea
--placeholder-color	Color of the placeholder text
--placeholder-font-style	Style of the placeholder text
--placeholder-font-weight	Weight of the placeholder text
--placeholder-opacity	Opacity of the placeholder text