设计支持库中不同模块的Android SDK兼容性

Question

I would like to create a bottom navigation in my application and I found an easy way with Bottom Navigation provided from Material Design .

My only problem is that I want the application to run on Android SDK 23 and I can see that Bottom Navigation from Material requires compile 'com.android.support:design:25.0.0' which requires 'com.android.support:appcompat-v7:25.0.0' . Currently I'm using 23.4.0 and I'm assuming that changing this will make my application to work on Android SDK 25 and up only.

Is this correct?

Answer 1

No. That is not correct. There's a big important difference between compile version and minimum version. This change is only in compile version.

• Compile version is the version your compiler will look at the moment it's compiling your code. That is only for the compiler to know which methods are available on the device. For example, to know that an Activity has a findViewById and that a ViewGroup have a addView . As long you don't use a method that is higher that your minimum it makes no difference.

• Minimum version that is the one you're telling the Google Play and the Android system the minimum where your app can be installed and that it should work fine. That's the one that limits which version to it can be installed.

For more on that I suggest you to read the official training materials here https://developer.android.com/training/material/compatibility.html and more specific the section "Check the System Version" https://developer.android.com/training/material/compatibility.html#CheckVersion

Answer 2

Don't worry, you refer to compile 'com.android.support:design:25.0.0 that´s just your dependency, so first at all

1.- If you want to use 'com.android.support:design:25.0.0 you should use at least building version 25:

compileSdkVersion 25
buildToolsVersion '25.0.0'

2.- Your app works with 'com.android.support:design:25.0.0 if you defined in your gradle a minimun SDK or target SDK less than 25:

minSdkVersion 15
targetSdkVersion 25

Now look this gradle, is from an app that works on API 19 and the Bottom Navigation View works fine

android {
    compileSdkVersion 25
    buildToolsVersion '25.0.0'
    defaultConfig {
        applicationId "**********"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        multiDexEnabled = true
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    dexOptions {
        jumboMode true
    }
    buildTypes {
        release {
            minifyEnabled false
            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-v7:25.3.0'
    compile 'com.android.support:support-v4:25.3.0'
    compile 'com.android.support:design:25.3.0'
    compile 'com.github.PhilJay:MPAndroidChart:v3.0.1'
    testCompile 'junit:junit:4.12'
}