Display

NOTE

The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import display from '@ohos.display';

DisplayState

Provides the state of a display.

System capability: SystemCapability.WindowManager.WindowManager.Core

Name	Default Value	Description
STATE_UNKNOWN	0	Unknown.
STATE_OFF	1	The display is shut down.
STATE_ON	2	The display is powered on.
STATE_DOZE	3	The display is in sleep mode.
STATE_DOZE_SUSPEND	4	The display is in sleep mode, and the CPU is suspended.
STATE_VR	5	The display is in VR mode.
STATE_ON_SUSPEND	6	The display is powered on, and the CPU is suspended.

Display

Describes the attributes of a display.

System capability: SystemCapability.WindowManager.WindowManager.Core

Name	Type	Readable	Writable	Description
id	number	Yes	No	ID of the display.
name	string	Yes	No	Name of the display.
alive	boolean	Yes	No	Whether the display is alive.
state	DisplayState	Yes	No	State of the display.
refreshRate	number	Yes	No	Refresh rate of the display.
rotation	number	Yes	No	Screen rotation angle of the display.
width	number	Yes	No	Width of the display, in pixels.
height	number	Yes	No	Height of the display, in pixels.
densityDPI	number	Yes	No	Screen density of the display, in DPI.
densityPixels	number	Yes	No	Screen density of the display, in pixels.
scaledDensity	number	Yes	No	Scaling factor for fonts displayed on the display.
xDPI	number	Yes	No	Exact physical dots per inch of the screen in the horizontal direction.
yDPI	number	Yes	No	Exact physical dots per inch of the screen in the vertical direction.

display.getDefaultDisplay

getDefaultDisplay(callback: AsyncCallback<Display>): void

Obtains the default display object.

System capability: SystemCapability.WindowManager.WindowManager.Core

Parameters

Name	Type	Mandatory	Description
callback	AsyncCallback<Display>	Yes	Callback used to return the default display object.

Example

var displayClass = null;
display.getDefaultDisplay((err, data) => {
    if (err.code) {
        console.error('Failed to obtain the default display object. Code:  ' + JSON.stringify(err));
        return;
    }
    console.info('Succeeded in obtaining the default display object. Data:' + JSON.stringify(data));
    displayClass = data;
});

display.getDefaultDisplay

getDefaultDisplay(): Promise<Display>

Obtains the default display object.

System capability: SystemCapability.WindowManager.WindowManager.Core

Return value

Type	Description
Promise<Display>	Promise used to return the default display object.

Example

let promise = display.getDefaultDisplay();
promise.then(() => {
    console.log('getDefaultDisplay success');
}).catch((err) => {
    console.log('getDefaultDisplay fail: ' + JSON.stringify(err));
});

display.getAllDisplay

getAllDisplay(callback: AsyncCallback<Array<Display>>): void

Obtains all the display objects.

System capability: SystemCapability.WindowManager.WindowManager.Core

Parameters

Name	Type	Mandatory	Description
callback	AsyncCallback<Array<Display>>	Yes	Callback used to return all the display objects.

Example

display.getAllDisplay((err, data) => {
    if (err.code) {
        console.error('Failed to obtain all the display objects. Code: ' + JSON.stringify(err));
        return;
    }
    console.info('Succeeded in obtaining all the display objects. Data: ' + JSON.stringify(data))
});

display.getAllDisplay

getAllDisplay(): Promise<Array<Display>>

Obtains all the display objects.

System capability: SystemCapability.WindowManager.WindowManager.Core

Return value

Type	Description
Promise<Array<Display>>	Promise used to return an array containing all the display objects.

Example

let promise = display.getAllDisplay();
promise.then(() => {
    console.log('getAllDisplay success');
}).catch((err) => {
    console.log('getAllDisplay fail: ' + JSON.stringify(err));
});

display.on('add'|'remove'|'change')

on(type: 'add'|'remove'|'change', callback: Callback<number>): void

Enables listening.

System capability: SystemCapability.WindowManager.WindowManager.Core

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Listening type. The available values are as follows: - add: listening for whether a display is added - remove: listening for whether a display is removed - change: listening for whether a display is changed
callback	Callback<number>	Yes	Callback used to return the ID of the display.

Example

var type = "add";
var callback = (data) => {
    console.info('Listening enabled. Data: ' + JSON.stringify(data))
}
display.on(type, callback);

display.off('add'|'remove'|'change')

off(type: 'add'|'remove'|'change', callback?: Callback<number>): void

Disables listening.

System capability: SystemCapability.WindowManager.WindowManager.Core

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Listening type. The available values are as follows: - add: listening for whether a display is added - remove: listening for whether a display is removed - change: listening for whether a display is changed
callback	Callback<number>	No	Callback used to return the ID of the display.

Example

var type = "remove";
display.off(type);