build_android/assets/scripts/RichTextAutoResize.ts

import { _decorator, Component, RichText, Node, UITransform } from 'cc';
const { ccclass, property } = _decorator;

@ccclass('RichTextAutoFontSize')
export class RichTextAutoFontSize extends Component {

    @property({ type: RichText })
    richText: RichText = null;

    start() {
        this.adjustFontSize();
    }

    adjustFontSize() {
        if (!this.richText) {
            console.warn('RichText component not found!');
            return;
        }

        const parentTransform = this.node.parent.getComponent(UITransform);
        const richTextTransform = this.richText.node.getComponent(UITransform);

        if (!parentTransform || !richTextTransform) {
            console.warn('UITransform component not found!');
            return;
        }

        while (richTextTransform.width > parentTransform.width || richTextTransform.height > parentTransform.height) {
            this.richText.fontSize--;

            // 强制更新渲染
            this.richText.enabled = false;
            this.richText.enabled = true;

            // 重新获取更新后的宽高
            richTextTransform.width = this.richText.node.getComponent(UITransform).width;
            richTextTransform.height = this.richText.node.getComponent(UITransform).height;
        }
    }
}