记录一种可以方便查看 dependency 的方法，经常遇到各种引用冲突导致的编译不通过的错误。
直接在Teminal 里面输入 gradlew app:dependencies 回车之后等一会儿就可以查看了
+--- com.google.android.wearable:wearable:2.3.0
+--- com.google.android.gms:play-services-cast-framework:15.0.0
| +--- com.android.support:mediarouter-v7:26.1.0
| | +--- com.android.support:appcompat-v7:26.1.0
| | | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | | +--- com.android.support:support-v4:26.1.0
| | | | +--- com.android.support:support-compat:26.1.0
| | | | | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | | | | \--- android.arch.lifecycle:runtime:1.0.0
| | | | | +--- android.arch.lifecycle:common:1.0.0
| | | | | \--- android.arch.core:common:1.0.0
| | | | +--- com.android.support:support-media-compat:26.1.0
| | | | | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | | | | \--- com.android.support:support-compat:26.1.0 (*)
| | | | +--- com.android.support:support-core-utils:26.1.0
| | | | | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | | | | \--- com.android.support:support-compat:26.1.0 (*)
| | | | +--- com.android.support:support-core-ui:26.1.0
| | | | | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | | | | \--- com.android.support:support-compat:26.1.0 (*)
| | | | \--- com.android.support:support-fragment:26.1.0
| | | | +--- com.android.support:support-compat:26.1.0 (*)
| | | | +--- com.android.support:support-core-ui:26.1.0 (*)
| | | | \--- com.android.support:support-core-utils:26.1.0 (*)
| | | +--- com.android.support:support-vector-drawable:26.1.0
| | | | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | | | \--- com.android.support:support-compat:26.1.0 (*)
| | | \--- com.android.support:animated-vector-drawable:26.1.0
| | | +--- com.android.support:support-vector-drawable:26.1.0 (*)
| | | \--- com.android.support:support-core-ui:26.1.0 (*)
| | \--- com.android.support:palette-v7:26.1.0
| | +--- com.android.support:support-compat:26.1.0 (*)
| | \--- com.android.support:support-core-utils:26.1.0 (*)
| +--- com.android.support:recyclerview-v7:26.1.0
| | +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| | +--- com.android.support:support-compat:26.1.0 (*)
| | \--- com.android.support:support-core-ui:26.1.0 (*)
| +--- com.google.android.gms:play-services-base:[15.0.0,16.0.0) -> 15.0.1
| | +--- com.google.android.gms:play-services-basement:[15.0.1] -> 15.0.1
| | | \--- com.android.support:support-v4:26.1.0 (*)
| | \--- com.google.android.gms:play-services-tasks:[15.0.1] -> 15.0.1
| | \--- com.google.android.gms:play-services-basement:[15.0.1] -> 15.0.1 (*)
| +--- com.google.android.gms:play-services-basement:[15.0.0,16.0.0) -> 15.0.1 (*)
| \--- com.google.android.gms:play-services-cast:[15.0.0] -> 15.0.0
| +--- com.android.support:mediarouter-v7:26.1.0 (*)
| +--- com.google.android.gms:play-services-base:[15.0.0,16.0.0) -> 15.0.1 (*)
| +--- com.google.android.gms:play-services-basement:[15.0.0,16.0.0) -> 15.0.1 (*)
| +--- com.google.android.gms:play-services-flags:[15.0.0,16.0.0) -> 15.0.1
| | +--- com.google.android.gms:play-services-base:[15.0.1] -> 15.0.1 (*)
| | \--- com.google.android.gms:play-services-basement:[15.0.1] -> 15.0.1 (*)
| \--- com.google.android.gms:play-services-tasks:[15.0.0,16.0.0) -> 15.0.1 (*)
+--- com.google.android.support:wearable:2.3.0
| +--- com.android.support:percent:26.0.2 -> 26.1.0
| | \--- com.android.support:support-compat:26.1.0 (*)
| +--- com.android.support:support-v4:26.0.2 -> 26.1.0 (*)
| +--- com.android.support:support-annotations:26.0.2 -> 27.0.0
| \--- com.android.support:recyclerview-v7:26.0.2 -> 26.1.0 (*)
+--- com.android.support:appcompat-v7:26.1.0 (*)
+--- com.android.support:cardview-v7:26.1.0
| \--- com.android.support:support-annotations:26.1.0 -> 27.0.0
+--- com.android.support:mediarouter-v7:26.1.0 (*)
+--- com.android.support:leanback-v17:26.1.0
| +--- com.android.support:support-compat:26.1.0 (*)
| +--- com.android.support:support-core-ui:26.1.0 (*)
| +--- com.android.support:support-media-compat:26.1.0 (*)
| +--- com.android.support:support-fragment:26.1.0 (*)
| \--- com.android.support:recyclerview-v7:26.1.0 (*)
+--- com.android.support:design:26.1.0
| +--- com.android.support:support-v4:26.1.0 (*)
| +--- com.android.support:appcompat-v7:26.1.0 (*)
| +--- com.android.support:recyclerview-v7:26.1.0 (*)
| \--- com.android.support:transition:26.1.0
| +--- com.android.support:support-annotations:26.1.0 -> 27.0.0
| \--- com.android.support:support-v4:26.1.0 (*)
+--- com.android.support:percent:26.1.0 (*)
\--- com.google.android.exoplayer:exoplayer:2.7.3
+--- com.google.android.exoplayer:exoplayer-core:2.7.3
| \--- com.android.support:support-annotations:27.0.0
+--- com.google.android.exoplayer:exoplayer-dash:2.7.3
| +--- com.google.android.exoplayer:exoplayer-core:2.7.3 (*)
| \--- com.android.support:support-annotations:27.0.0
+--- com.google.android.exoplayer:exoplayer-hls:2.7.3
| +--- com.android.support:support-annotations:27.0.0
| \--- com.google.android.exoplayer:exoplayer-core:2.7.3 (*)
+--- com.google.android.exoplayer:exoplayer-smoothstreaming:2.7.3
| +--- com.google.android.exoplayer:exoplayer-core:2.7.3 (*)
| \--- com.android.support:support-annotations:27.0.0
\--- com.google.android.exoplayer:exoplayer-ui:2.7.3
+--- com.google.android.exoplayer:exoplayer-core:2.7.3 (*)
\--- com.android.support:support-annotations:27.0.0
上面应该可以看出来
com.google.android.exoplayer:exoplayer:2.7.3
这个东西里面以用了
com.android.support:support-annotations:27.0.0
跟我的build 里面配置的编译版本不一致。