鸿蒙中调整应用内文字大小

1、ui

       Stack() {Row() {ForEach([1, 2, 3, 4], (item: number) => {Text().width(3).height(20).backgroundColor(Color.Black).margin(item === 2 ? { left: 8 } : item === 3 ? { left: 7 } : { left: 0 })})}.width('97%').justifyContent(FlexAlign.SpaceBetween).padding({ right: 2 })Slider({value: this.changeFontSize === CommonConstants.SET_SIZE_HUGE? CommonConstants.SET_SLIDER_MAX : this.changeFontSize === 16 ? this.changeFontSize = 16.700000762939453 :this.changeFontSize === 19 ? this.changeFontSize = 19.399999618530273 : this.changeFontSize,min: CommonConstants.SET_SLIDER_MIN,max: CommonConstants.SET_SLIDER_MAX,step: CommonConstants.SET_SLIDER_STEP,style: SliderStyle.OutSet}).blockColor(Color.White).trackColor(Color.Black).selectedColor(Color.Black).showSteps(true).onChange(async (value: number) => {if (this.changeFontSize === 0) {this.changeFontSize = await PreferencesUtil.getChangeFontSize();return;}this.changeFontSize =(Math.floor(value) === CommonConstants.SET_SLIDER_MAX ? CommonConstants.SET_SIZE_HUGE :Math.floor(value));PreferencesUtil.saveChangeFontSize(this.changeFontSize);})}

2、工具类

        1.

/** Copyright (c) 2022 Huawei 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.*//*** Common constants for all features.*/
export default class CommonConstants {/*** Small font size.*/static readonly SET_SIZE_SMALL: number = 14;/*** Normal font size.*/static readonly SET_SIZE_NORMAL: number = 16.7;/*** Large font size.*/static readonly SET_SIZE_LARGE: number = 19.4;/*** Extra large font size.*/static readonly SET_SIZE_EXTRA_LARGE: number = 20;/*** Huge font size.*/static readonly SET_SIZE_HUGE: number = 24;/*** Slider min value.*/static readonly SET_SLIDER_MIN: number = 14;/*** Slider max value.*/static readonly SET_SLIDER_MAX: number = 22;/*** Slider step length.*/static readonly SET_SLIDER_STEP: number = 2.7;/*** The setting list display index.*/static readonly DISPLAY_INDEX: number = 0;/*** The setting list voice index.*/static readonly VOICE_INDEX: number = 1;/*** The setting list slice start index.*/static readonly START_INDEX: number = 2;/*** The setting list slice font index.*/static readonly SET_FONT_INDEX: number = 3;/*** The setting list slice end index.*/static readonly END_INDEX: number = 6;/*** The set font size url.*/static readonly SET_URL: string = 'pages/SetFontSizePage';
}

        2.

/** Copyright (c) 2023 Huawei 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.*/export class GlobalContext {private constructor() { }private static instance: GlobalContext;private _objects = new Map<string, Object>();public static getContext(): GlobalContext {if (!GlobalContext.instance) {GlobalContext.instance = new GlobalContext();}return GlobalContext.instance;}getObject(value: string): Object | undefined {return this._objects.get(value);}setObject(key: string, objectClass: Object): void {this._objects.set(key, objectClass);}
}

        3.

/** Copyright (c) 2022 Huawei 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 { preferences } from '@kit.ArkData';
import { GlobalContext } from '../utils/GlobalContext';const TAG = '[PreferencesUtil]';
const PREFERENCES_NAME = 'myPreferences';
const KEY_APP_FONT_SIZE = 'appFontSize';/*** The PreferencesUtil provides preferences of create, save and query.*/
export class PreferencesUtil {createFontPreferences(context: Context) {let fontPreferences: Function = (() => {let preference: Promise<preferences.Preferences> = preferences.getPreferences(context, PREFERENCES_NAME);return preference;});GlobalContext.getContext().setObject('getFontPreferences', fontPreferences);}saveDefaultFontSize(fontSize: number) {let getFontPreferences: Function = GlobalContext.getContext().getObject('getFontPreferences') as Function;getFontPreferences().then((preferences: preferences.Preferences) => {preferences.has(KEY_APP_FONT_SIZE).then(async (isExist: boolean) => {if (!isExist) {await preferences.put(KEY_APP_FONT_SIZE, fontSize);preferences.flush();}}).catch((err: Error) => {});}).catch((err: Error) => {});}saveChangeFontSize(fontSize: number) {let getFontPreferences: Function = GlobalContext.getContext().getObject('getFontPreferences') as Function;getFontPreferences().then(async (preferences: preferences.Preferences) => {await preferences.put(KEY_APP_FONT_SIZE, fontSize);preferences.flush();}).catch((err: Error) => {});}async getChangeFontSize() {let fontSize: number = 0;let getFontPreferences: Function = GlobalContext.getContext().getObject('getFontPreferences') as Function;// const preferences: dataPreferences.Preferences = await getFontPreferences();fontSize = await (await getFontPreferences()).get(KEY_APP_FONT_SIZE, fontSize);return fontSize;}async deleteChangeFontSize() {let getFontPreferences: Function = GlobalContext.getContext().getObject('getFontPreferences') as Function;const preferences: preferences.Preferences = await getFontPreferences();let deleteValue = preferences.delete(KEY_APP_FONT_SIZE);deleteValue.then(() => {}).catch((err: Error) => {});}
}export default new PreferencesUtil();

4.

/** Copyright (c) 2022 Huawei 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.*//*** Style constants for all features.*/
export default class StyleConstants {/*** The head aspect ratio.*/static readonly HEAD_ASPECT_RATIO: number = 1;/*** Weight to fill.*/static readonly WEIGHT_FULL: number = 1;/*** Minimum height of two lines of text.*/static readonly DOUBLE_ROW_MIN: number = 28;/*** Unit of fp.*/static readonly UNIT_FP: string = 'fp';/*** Full the width.*/static readonly FULL_WIDTH: string = '100%';/*** Full the height.*/static readonly FULL_HEIGHT: string = '100%';/*** The percentage of 7.2.*/static readonly TITLE_BAR_HEIGHT_PERCENT: string = '7.2%';/*** The percentage of 93.3.*/static readonly BLOCK_WIDTH_PERCENT: string = '93.3%';/*** The percentage of 0.5.*/static readonly BLOCK_TOP_MARGIN_FIRST_PERCENT: string = '0.5%';/*** The percentage of 1.5.*/static readonly BLOCK_TOP_MARGIN_SECOND_PERCENT: string = '1.5%';/*** The percentage of 23.8.*/static readonly DIVIDER_END_MARGIN_PERCENT: string = '23.8%';/*** The percentage of 6.7.*/static readonly HEAD_RIGHT_PERCENT: string = '6.7%';/*** The percentage of 2.2.*/static readonly HEAD_LEFT_PERCENT: string = '2.2%';/*** The percentage of 64.4.*/static readonly MAX_CHAT_WIDTH_PERCENT: string = '64.4%';/*** The percentage of 3.1.*/static readonly CHAT_TOP_MARGIN_PERCENT: string = '3.1%';/*** The percentage of 6.5.*/static readonly SLIDER_LAYOUT_LEFT_PERCENT: string = '6.5%';/*** The percentage of 3.2.*/static readonly SLIDER_LAYOUT_TOP_PERCENT: string = '3.2%';/*** The percentage of 8.9.*/static readonly SET_CHAT_HEAD_SIZE_PERCENT: string = '8.9%';/*** The percentage of 12.5.*/static readonly A_WIDTH_PERCENT: string = '12.5%';/*** The percentage of 75.*/static readonly SLIDER_WIDTH_PERCENT: string = '75%';/*** The percentage of 3.3.*/static readonly SLIDER_HORIZONTAL_MARGIN_PERCENT: string = '3.3%';/*** The percentage of 1.*/static readonly SLIDER_TOP_MARGIN_PERCENT: string = '1%';/*** The percentage of 6.2.*/static readonly SLIDER_BOTTOM_MARGIN_PERCENT: string = '6.2%';
}

3、使用

  @State changeFontSize: number = CommonConstants.SET_SIZE_NORMAL;onPageShow() {PreferencesUtil.getChangeFontSize().then((value) => {this.changeFontSize = value;});}Text('字体大小').fontSize(this.changeFontSize)

4.配置文件（api13，不需要配置，api13以下需要）

详情文档中心

AppScope/resources/base/profile/configuration.json中

{"configuration": {"fontSizeScale": "nonFollowSystem"}
}

app.json5中

    "configuration": "$profile:configuration",