android – 什么是versionCodeMajor？和versionCode有什么区别？

我刚刚发现在Android Pie中不推荐使用PackageInfo.versionCode.他们指出你使用PackageInfo.getLongVersionCode().这种新方法的JavaDoc是：

Return 07002 and 07003 combined together as a single long value. The 07003 is placed in the upper 32 bits.

但是什么是versionCodeMajor？我该如何使用它？ versionCodeMajor和旧的versionCode有什么区别？

它的文档几乎没有说：

Internal major version code. This is essentially additional high bits for the base version code; it has no other meaning than that higher numbers are more recent. This is not a version number generally shown to the user, that is usually supplied with R.attr.versionName.

解决方法:

到目前为止,我发现使用Android Studio 3.2.1设置versionCodeMajor的唯一方法是通过AndroidManifest.xml并禁用InstantRun.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:versionCodeMajor="8" [...]

‘因为你在build.gradle文件中设置它

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.xxx.myapplicationp"
        minSdkVersion 'P'
        targetSdkVersion 'P'
        versionCode 127
        //versionCodeMajor 8
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

Could not find method versionCodeMajor() for arguments

因此,在AndroidManifest.xml中设置您选择的主要版本代码并禁用InstantRun后,您可以通过以下方式获取它：

static long getAppVersionCode(Context context) throws PackageManager.NameNotFoundException {
        PackageInfo pinfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
        long returnValue = Long.MAX_VALUE;
        //if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P
                && !"P".equals(Build.VERSION.CODENAME) /* This 'cause the dev preview */) {
            returnValue = pinfo.versionCode;
        } else {
            returnValue = pinfo.getLongVersionCode();
            Log.d("AAA", "Full long value: " + returnValue);
            Log.d("AAA", "Major Version Code (your chosen one) " + (returnValue >> 32)); // 8 in this scenario
            Log.d("AAA", "Version Code (your chosen one) " + (int)(returnValue & 0x00000000ffffffff)); // 127 in this scenario
        }
        return returnValue;
    }

或者你可以像这样使用PackageInfoCompat：

static long getAppVersionCode(Context context) throws PackageManager.NameNotFoundException {
        PackageInfo pinfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
        long returnValue = Long.MAX_VALUE;
        returnValue = PackageInfoCompat.getLongVersionCode(pinfo);
        if (BuildConfig.DEBUG) {
            int majorCode = (int)(returnValue >> 32);
            int versionCode = (int)(returnValue & 0x00000000ffffffff); // or simply returnValue

            Log.d("AAA", "Full long value: " + returnValue);
            Log.d("AAA", "Major Version Code (your chosen one) " + majorCode); // 8 in this scenario
            Log.d("AAA", "Version Code (your chosen one) " + versionCode); // 127 in this scenario
        }
        return returnValue;
    }

这应该回答如何使用它或一种方式.

关于何时以及为何使用它……我想这取决于你…正如你所指出的那样,文档会告诉你为什么要使用它.什么文档说你应该向你的用户呈现众所周知的versionNumber.

我猜他们会向versionCode添加更多位,因为他们需要更多的版本来进行版本化^^’

也就是说,如果你没有在AndroidManifest.xml或build.gradle文件中设置versionCodeMajor(当它处理它时),或者你将它设置为0,那么这个值与旧的versionNumber弃用字段相同.

标签：android-9-0-pie,android
来源： https://codeday.me/bug/20190823/1697213.html