所有com.android.support库必须使用与25.3.1版完全相同的版本规范

这个问题已经回答了很多次，但我仍然不知道如何解决它。我在build.gradle

编译'com.android.support:appcompat-v7:25.3.1'

中的这一行中遇到错误。我不知道我需要在build.gradle中添加什么才能使其工作。我有一个完整的依赖关系树，但我不知道我需要更改什么或如何更改

compile - Classpath for compiling the main sources.
    +--- com.android.support:appcompat-v7:25.3.1
    |    +--- com.android.support:support-annotations:25.3.1
    |    +--- com.android.support:support-v4:25.3.1
    |    |    +--- com.android.support:support-compat:25.3.1
    |    |    |    \--- com.android.support:support-annotations:25.3.1
    |    |    +--- com.android.support:support-media-compat:25.3.1
    |    |    |    +--- com.android.support:support-annotations:25.3.1
    |    |    |    \--- com.android.support:support-compat:25.3.1 (*)
    |    |    +--- com.android.support:support-core-utils:25.3.1
    |    |    |    +--- com.android.support:support-annotations:25.3.1
    |    |    |    \--- com.android.support:support-compat:25.3.1 (*)
    |    |    +--- com.android.support:support-core-ui:25.3.1
    |    |    |    +--- com.android.support:support-annotations:25.3.1
    |    |    |    \--- com.android.support:support-compat:25.3.1 (*)
    |    |    \--- com.android.support:support-fragment:25.3.1
    |    |         +--- com.android.support:support-compat:25.3.1 (*)
    |    |         +--- com.android.support:support-media-compat:25.3.1 (*)
    |    |         +--- com.android.support:support-core-ui:25.3.1 (*)
    |    |         \--- com.android.support:support-core-utils:25.3.1 (*)
    |    +--- com.android.support:support-vector-drawable:25.3.1
    |    |    +--- com.android.support:support-annotations:25.3.1
    |    |    \--- com.android.support:support-compat:25.3.1 (*)
    |    \--- com.android.support:animated-vector-drawable:25.3.1
    |         \--- com.android.support:support-vector-drawable:25.3.1 (*)
    +--- com.android.support:support-v4:25.3.1 (*)
    +--- com.google.firebase:firebase-database:10.2.0
    |    +--- com.google.android.gms:play-services-basement:10.2.0
    |    |    \--- com.android.support:support-v4:24.0.0 -> 25.3.1 (*)
    |    +--- com.google.firebase:firebase-database-connection:10.2.0
    |    |    +--- com.google.android.gms:play-services-basement:10.2.0 (*)
    |    |    \--- com.google.firebase:firebase-common:10.2.0
    |    |         +--- com.google.android.gms:play-services-basement:10.2.0 (*)
    |    |         \--- com.google.android.gms:play-services-tasks:10.2.0
    |    |              \--- com.google.android.gms:play-services-basement:10.2.0 (*)
    |    +--- com.google.firebase:firebase-common:10.2.0 (*)
    |    \--- com.google.android.gms:play-services-tasks:10.2.0 (*)
    +--- com.sromku:simple-storage:1.2.0
    +--- com.squareup.picasso:picasso:2.5.2
    +--- com.android.support:recyclerview-v7:25.3.1
    |    +--- com.android.support:support-annotations:25.3.1
    |    +--- com.android.support:support-compat:25.3.1 (*)
    |    \--- com.android.support:support-core-ui:25.3.1 (*)
    +--- at.blogc:expandabletextview:1.0.3
    +--- it.neokree:MaterialTabs:0.11
    |    +--- com.github.markushi:android-ui:1.2
    |    \--- com.android.support:appcompat-v7:21.0.3 -> 25.3.1 (*)
    +--- project :android-pdf-viewer
    |    \--- com.github.barteksc:pdfium-android:1.5.0
    |         \--- com.android.support:support-v4:21.0.3 -> 25.3.1 (*)
    \--- com.google.firebase:firebase-core:10.2.0
         \--- com.google.firebase:firebase-analytics:10.2.0
              +--- com.google.android.gms:play-services-basement:10.2.0 (*)
              +--- com.google.firebase:firebase-common:10.2.0 (*)
              \--- com.google.firebase:firebase-analytics-impl:10.2.0
                   +--- com.google.android.gms:play-services-basement:10.2.0 (*)
                   +--- com.google.firebase:firebase-iid:10.2.0
                   |    +--- com.google.android.gms:play-services-basement:10.2.0 (*)
                   |    \--- com.google.firebase:firebase-common:10.2.0 (*)
                   +--- com.google.firebase:firebase-common:10.2.0 (*)
                   \--- com.google.android.gms:play-services-tasks:10.2.0 (*)

---

可能是您的pdf库的问题

+--- project :android-pdf-viewer
|    \--- com.github.barteksc:pdfium-android:1.5.0
|         \--- com.android.support:support-v4:21.0.3 -> 25.3.1 (*)

它仍然使用支持库v4版本21.0.3

您可以尝试将pdf库升级到1.7.0

\--- com.github.barteksc:pdfium-android:1.7.0
 \--- com.android.support:support-v4:25.3.1 (*)

或者在

build.gradle

中手动将support v4版本指定为

25.3.1

compile 'com.github.barteksc:pdfium-android:1.5.0'
compile 'com.android.support:support-v4:25.3.1'

---

您使用的最大api级别是多少？minSdkVersion 15 targetSdkVersion 25请编辑您的问题并提供您收到的确切错误消息。它应该比你问题标题中的内容更多。