Program type already present:android.support.v4.app.backstackrecord$Op
(程序类型已经存在:android.support.v4.app.backstackrecord$Op)
调试过程中如果出现上述错误
最好的解决办法是把build.gradle文件中的下面部分:
dependencies { implementation fileTree(include: ['*.jar'], dir: 'libs') implementation 'com.android.support:appcompat-v7:27.1.1' implementation 'com.android.support:recyclerview-v7:27.1.1' implementation 'com.android.support:design:27.1.1' implementation 'com.squareup.picasso:picasso:2.5.2' testCompile 'junit:junit:4.12' implementation 'com.google.code.gson:gson:2.2.4' implementation 'com.android.support.constraint:constraint-layout:1.1.1' testImplementation 'junit:junit:4.12' androidTestImplementation 'com.android.support.test:runner:1.0.2' androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2' implementation files('libs/okhttp-3.2.0.jar') }修改为一样 27.1.1
亲测可以解决这个异常!