OpenHarmony如何查询屏幕/窗口尺寸

如何查询屏幕/窗口尺寸

在应用开发过程中，为了在不同的设备上取得更好的显示效果，开发者可能需要查询屏幕尺寸或应用显示窗口尺寸。

• 通过display查询显示设备的属性（包括屏幕宽、高和屏幕密度等），详见屏幕属性。

// @ts-nocheck
/*
 * Copyright (c) 2021 JianGuo Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import deviceInfo from'@ohos.deviceInfo'
import parameter from '@ohos.systemParameter'
import display from '@ohos.display';

@Entry
@Component
struct GetDeviceTypeSample {
  @State deviceType: string = 'deviceType';
  @State device: string = 'device';
  @State displayInfo: string = 'displayInfo';

  aboutToAppear() {
    try {
      this.deviceType = parameter.getSync("const.build.characteristics");
    } catch(e) {
      console.log("getSync unexpected error: " + e);
    }
  }
  build() {
    Column() {
      Text("设备属性").fontSize(36)
      //通过js接口查询指定系统参数（const.build.characteristics）进而确定设备类型
      Text(this.deviceType).fontSize(28).onClick(() => {
        try {
          this.deviceType = parameter.getSync("const.build.characteristics");
          console.log("坚果"
          +
          this.deviceType);
        } catch (e) {
          console.log("getSync unexpected error: " + e);
        }

      })
      //通过deviceInfo查询设备类型
      Text(   this.device).fontSize(28).onClick(() => {
        this.device= deviceInfo.deviceType;
      })
      //通过display查询显示设备的属性（包括屏幕宽、高和屏幕密度等）
      Text(this.displayInfo).fontSize(28).onClick(() => {
        display.getDefaultDisplay()
          .then((displayInfo) => {
            console.info('Display width: ' + displayInfo.width);
            console.info('Display height: ' + displayInfo.height);
            console.info('Display density: ' + displayInfo.densityDPI);
            this.displayInfo=JSON.stringify(displayInfo);
            console.info('Display density: ' +   JSON.stringify(displayInfo));

          })
          .catch((error) => {
            console.error('Failed to obtain the default display size. Cause:  ' + JSON.stringify(error));
          })

      })
    }
    .width('100%')
    .height('100%').justifyContent(FlexAlign.Center).alignItems(HorizontalAlign.Center)
  }
}

运行之后，在控制台打印

{"alive":true,"densityDPI":560,"densityPixels":3.5,"height":2560,"id":0,"name":"内置屏幕","refreshRate":60.000004,"rotation":0,"scaledDensity":3.5,"state":2,"width":1440,"xDPI":560,"yDPI":560}

下面是参数描述

Display

描述display对象的属性。

系统能力： 以下各项对应的系统能力均为 SystemCapability.WindowManager.WindowManager.Core。