求大佬告知如何获取设备的dpi值

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)); 
}