问题：

A problem occurred evaluating root project 'amap_core_fluttify'.

> Cannot convert a null value to an object of type Dependency.

? The following types/formats are supported:

? ? - Instances of Dependency.

? ? - String or CharSequence values, for example 'org.gradle:gradle-core:1.0'.

? ? - Maps, for example [group: 'org.gradle', name: 'gradle-core', version: '1.0'].

? ? - FileCollections, for example files('some.jar', 'someOther.jar').

? ? - Projects, for example project(':some:project:path').

? ? - ClassPathNotation, for example gradleApi().

解决方案：

在 android/build.gradle中添加
subprojects{

? ? afterEvaluate{project->

? ? ? ? if (project.hasProperty("android")) {

????????????????android{

? ? ? ? ? ? ? ? compileSdkVersion29

? ? ? ? ? ? }

? ? ? ? }

????????}

}