Android Proguard minifyEnable真的不行

Question

在我的项目中，我通过更改minifyEnable true启用proguard。当我反编译项目时，我看到我的代码没有模仿。 我的build.gradle文件在这里：

apply plugin: 'com.android.application'

android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
    applicationId "com.material.design.canvas"
    minSdkVersion 21
    targetSdkVersion 25
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    debug {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
    release {
        shrinkResources true
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
testCompile 'junit:junit:4.12'
compile 'com.jakewharton:butterknife:7.0.1'
}