(in promise) MiniProgramError
Cannot read properties of null (reading 'length')
TypeError: Cannot read properties of null (reading 'length')
at _class2._callee$ (app-service.js:10139:26)
at s (app-service.js:3411:738)
at Generator.<anonymous> (app-service.js:3411:2075)
at Generator.next (app-service.js:3411:1101)
at asyncGeneratorStep (app-service.js:3381:58)
at c (app-service.js:3381:277)
请检查值，值为null的时候，是没有length属性的。