Graphics Development

How do I obtain the DPI of a device?

Applicable to: OpenHarmony 3.2 Beta5 (API version 9, stage model)

Solution

Import the @ohos.display module and call the getDefaultDisplaySync() API.

Example

import display from '@ohos.display'; 
let displayClass = null;
try {
  displayClass = display.getDefaultDisplaySync();
  console.info('Test densityDPI:' + JSON.stringify(displayClass.densityDPI));
} catch (exception) {
  console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
}

How do I hide the status bar to get the immersive effect?

Applicable to: OpenHarmony 3.2 Beta5 (API version 9, stage model)

Solution

1. Use onWindowStageCreate to obtain a windowClass object.

   onWindowStageCreate(windowStage) {
     // When the main window is created, set the main page for this ability.
     console.log("[Demo] MainAbility onWindowStageCreate")
     windowStage.getMainWindow((err, data) => {
       if (err.code) {
         console.error('Failed to obtain the main window.')
         return;
       }
       // Obtain a windowClass object.
       globalThis.windowClass = data; 
     })
   }
   

2. Enable the full-screen mode for the window and hide the status bar.

    globalThis.windowClass.setFullScreen(isFullScreen, (err, data) => {
     if (err.code) {
       console.error('Failed to enable the full-screen mode. Cause:' + JSON.stringify(err));
       return;
     }
       console.info('Succeeded in enabling the full-screen mode. Data: ' + JSON.stringify(data));
     });
   

How do I obtain the window width and height?

Applicable to: OpenHarmony SDK 3.2 Beta5 (API version 9, stage model)

Solution

Import the @ohos.window module, obtain a Window object, and use getWindowProperties() of the object to obtain the window properties. The windowRect field in the properties specifies the window width and height.

Example

import window from '@ohos.window';
let windowClass = null;
try {    
    let promise = window.getLastWindow(this.context);
    promise.then((data)=> {
        // Obtain a Window object.
        windowClass = data;
        try {
            // Obtain the window properties.
            let properties = windowClass.getWindowProperties();
            let rect = properties.windowRect;
            // rect.width: window width; rect.height: window height.
        } catch (exception) {
             console.error('Failed to obtain the window properties. Cause: ' + JSON.stringify(exception));
        }
        console.info('Succeeded in obtaining the top window. Data: ' + JSON.stringify(data));
    }).catch((err)=>{
        console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(err));
    });} catch (exception) {
    console.error('Failed to obtain the top window. Cause: ' + JSON.stringify(exception));
}