所以找到答案后回答我自己的问题我来这里是为了帮助别人
是否是第一次。当您在应用程序上单击运行时，您会收到X gradle构建错误如果您的错误中包含以下任何行，甚至只有一行，请尝试此解决方案
Launching lib\main.dart on sdk gphone x86 in debug mode...
FAILURE: Build Failed with an exception.
* What went wrong:
A problem occurred configuring root project 'android'.
> Could not resolve all artifacts for configuration ':classpath'.
> Could not download builder.jar (com.android.tools.build:builder:3.5.0)
> Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/builder/3.5.0/builder-3.5.0.jar'.
> Premature end of Content-Length delimited message body (expected: 8174407; received: 4456416
> Could not download bundletool.jar (com.android.tools.build:bundletool:0.9.0)
> Could not get resource 'https://dl.google.com/dl/android/maven2/com/android/tools/build/bundletool/0.9.0/bundletool-0.9.0.jar'.
> Premature end of Content-Length delimited message body (expected: 5248142; received: 4456416
转到此位置：-.Flutter/packages/Flutter_tools/gradle/Flutter.gradle
它应该像这样出现（或类似，不要担心您有备份文件） 并覆盖此代码
buildscript { repositories { jcenter() } dependencies { classpath ‘com.android.tools.build:gradle:3.1.2’ } }
With this
buildscript {
repositories {
maven {
url 'https://dl.google.com/dl/android/maven2'
}
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.1.2'
}
}
还是，您的问题没有解决？如果解决了，请不要尝试下一个，否则请尝试。（即使这不起作用，也将备份文件放到原 处，看看它是否起作用）
然后在你的android文件夹去到build.gradle（在你的项目文件去到android/build.gradle），并改变buildscript这个（不必担心对代码不是100％这样的。只需添加指定的行中所示的位置，这就是它）
buildscript {
repositories {
google()
mavenCentral() //add this line
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:3.2.1' // Doesn't matter what you have here
}
}
602392714
清零编程群