operation_wx/miniprogram_npm/tdesign-miniprogram/mixins/theme-change.js

const themeChangeBehavior = Behavior({
    data: {
        theme: 'light',
    },
    attached() {
        this._initTheme();
    },
    methods: {
        _initTheme() {
            const that = this;
            wx.getSystemInfo({
                success(res) {
                    that.setData({
                        theme: res.theme,
                    });
                },
            });
            wx.onThemeChange((res) => {
                that.setData({
                    theme: res.theme,
                });
            });
        },
    },
});
export default themeChangeBehavior;