我刚刚开始使用Ionic 4开发我的应用程序。目前为止，在启动项目时，我从未对原始代码进行任何修改（包括侧边菜单）。 在遇到其他许多错误后，我现在遇到了一个不知道如何解决的问题。 当我尝试执行以下命令时会出现该错误：
ionic cordova build android
FAILURE: Build completed with 2 failures.
1: Task failed with an exception.
-----------
* Where:
Build file 'D:\workspace\iganalytics\app\platforms\android\app\build.gradle' line: 148
* What went wrong:
A problem occurred evaluating project ':app'.
> Could not find method leftShift() for arguments [build_8ka4my3njl1nfn72j8pdlyfze$_run_closure6@5b9f348] on task ':app:cdvPrintProps' of type org.gradle.api.DefaultTask.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
==============================================================================
2: Task failed with an exception.
-----------
* What went wrong:
A problem occurred configuring project ':app'.
> compileSdkVersion is not specified.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
==============================================================================
* Get more help at https://help.gradle.org
BUILD FAILED in 1s
cmd: Command failed with exit code 1 Error output:
FAILURE: Build completed with 2 failures.
1: Task failed with an exception.
-----------
* Where:
Build file 'D:\workspace\iganalytics\app\platforms\android\app\build.gradle' line: 148
* What went wrong:
A problem occurred evaluating project ':app'.
> Could not find method leftShift() for arguments [build_8ka4my3njl1nfn72j8pdlyfze$_run_closure6@5b9f348] on task ':app:cdvPrintProps' of type org.gradle.api.DefaultTask.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
==============================================================================
2: Task failed with an exception.
-----------
* What went wrong:
A problem occurred configuring project ':app'.
> compileSdkVersion is not specified.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
==============================================================================
* Get more help at https://help.gradle.org
BUILD FAILED in 1s
[ERROR] An error occurred while running subprocess cordova.
cordova build android exited with exit code 1.
Re-running this command with the --verbose flag may provide more information.
我在config.xml中添加了这行代码：
<preference name="android-targetSdkVersion" value="28" />
未能成功。
build.gradle文件的第148行起始位置为：
task cdvPrintProps << {
println('cdvCompileSdkVersion=' + cdvCompileSdkVersion)
println('cdvBuildToolsVersion=' + cdvBuildToolsVersion)
println('cdvVersionCode=' + cdvVersionCode)
println('cdvVersionCodeForceAbiDigit=' + cdvVersionCodeForceAbiDigit)
println('cdvMinSdkVersion=' + cdvMinSdkVersion)
println('cdvBuildMultipleApks=' + cdvBuildMultipleApks)
println('cdvReleaseSigningPropertiesFile=' + cdvReleaseSigningPropertiesFile)
println('cdvDebugSigningPropertiesFile=' + cdvDebugSigningPropertiesFile)
println('cdvBuildArch=' + cdvBuildArch)
println('computedVersionCode=' + android.defaultConfig.versionCode)
android.productFlavors.each { flavor ->
println('computed' + flavor.name.capitalize() + 'VersionCode=' + flavor.versionCode)
}
}