小编use*_*909的帖子

我正在使用下面的gradle配置构建android项目:Android Studio 2.1.2

项目gradle文件:

dependencies {
    classpath 'com.android.tools.build:gradle:2.2.0-alpha4'
}

应用程序gradle文件:

android {
    compileSdkVersion 24
    buildToolsVersion '24.0.0'

    defaultConfig {
        applicationId "<my_app_id>"
        minSdkVersion 17
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"

        jackOptions {
            enabled true
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

应用程序始终构建失败并显示错误:

2016-06-26 22:26:52,282 [1868500]   WARN - nal.AbstractExternalSystemTask - Cause: com/android/build/gradle/internal/model/DefaultAndroidProject : Unsupported major.minor version 52.0 
com.intellij.openapi.externalSystem.model.ExternalSystemException: Cause: com/android/build/gradle/internal/model/DefaultAndroidProject : Unsupported major.minor version 52.0
    at org.jetbrains.plugins.gradle.service.project.AbstractProjectImportErrorHandler.createUserFriendlyError(AbstractProjectImportErrorHandler.java:106)
    at org.jetbrains.plugins.gradle.service.project.BaseProjectImportErrorHandler.getUserFriendlyError(BaseProjectImportErrorHandler.java:158)
    at org.jetbrains.plugins.gradle.service.project.BaseGradleProjectResolverExtension.getUserFriendlyError(BaseGradleProjectResolverExtension.java:457)
    at org.jetbrains.plugins.gradle.service.project.AbstractProjectResolverExtension.getUserFriendlyError(AbstractProjectResolverExtension.java:158)
    at com.android.tools.idea.gradle.project.AndroidGradleProjectResolver.getUserFriendlyError(AndroidGradleProjectResolver.java:350)
    at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver$ProjectConnectionDataNodeFunction.fun(GradleProjectResolver.java:373)
    at org.jetbrains.plugins.gradle.service.project.GradleProjectResolver$ProjectConnectionDataNodeFunction.fun(GradleProjectResolver.java:339)
    at …

我在Swift上有这个代码:

let items = doSomethingFuncToGetDataWithOptionalResults()
if let items = items {
    for item in items {
        // so something...
    }
} 

if let ...在这种情况下,任何人都可以帮助我避免.如果我们if let在这种情况下可以忽略它会更好.每次写这些陈述时我都很生气.

问候,