还在用老办法获取版本号或者签名信息吗？不如试试PackageInfoCompat吧！

前言

之前的很久时间，我们都是使用以下的方式获取应用的版本号，但在Android SDK 28中，谷歌弃用了该方式，推荐使用getLongVersionCode()

public int getSelfVersionCode(Context context){
        try {
            PackageManager packageManager = context.getPackageManager();
            PackageInfo info = packageManager.getPackageInfo(context.getPackageName(),0);
            return info.versionCode;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
            return -1;
        }
}

但 getLongVersionCode() 仅限API28及以上使用，所以我们需要判断版本号并做出对应处理。

那么，我们可以一步到位吗？

答案是可以的！

PackageInfoCompat

引入依赖

// Androidx
implementation 'androidx.appcompat:appcompat:1.3.0-rc01'

// Android Support
implementation 'com.android.support:appcompat-v7:28.0.0'

What is PackageInfoCompat？

PackageInfoCompat顾名思义，是用来代替PackageInfo部分功能的，里面仅包含三个静态方法

修饰符	方法参数	方法作用
static
Long	getLongVersionCode(
info: PackageInfo)	返回版本号
static MutableList<Signature!>
getSignatures(
packageManager: PackageManager, packageName: String)	获取签名数组
static
Boolean	hasSignatures(
packageManager: PackageManager, packageName: String,certificatesAndType: MutableMap<ByteArray!, Int!>, matchExact:
Boolean)	检查设备上的包是否包含一组证书。

使用

getLongVersionCode - 获取版本号，内部实现其实与上文提到的方法无异

public long getSelfVersionCode(Context context) {
    try {
        PackageManager packageManager = context.getPackageManager();
        PackageInfo info = packageManager.getPackageInfo(context.getPackageName(), 0);
        return PackageInfoCompat.getLongVersionCode(info);
        } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
        return -1;
    }
}

fun getSelfVersionCode(context: Context): Long {
    val packageManager = context.packageManager
    val info = packageManager.getPackageInfo(context.packageName, 0)
    return PackageInfoCompat.getLongVersionCode(info)
}

@SuppressWarnings("deprecation")
public static long getLongVersionCode(@NonNull PackageInfo info) {
    if (Build.VERSION.SDK_INT >= 28) {
        return info.getLongVersionCode();
    }
    return info.versionCode;
}

getSignatures - 获取应用签名， signatures 在SDK28中被 signingInfo 替代

Java
Kotlin

public String getSelfSignToSHA1(Context context) {
    try {
        PackageManager packageManager = context.getPackageManager();
        List<Signature> signatureList = PackageInfoCompat.getSignatures(packageManager,context.getPackageName());
        byte[] cert = signatureList.get(0).toByteArray();
        MessageDigest md = MessageDigest.getInstance("SHA1");
        byte[] publicKey = md.digest(cert);
        StringBuilder hexString = new StringBuilder();
        for (int i = 0; i < publicKey.length; i++) {
            String appendString = Integer.toHexString(0xFF & publicKey[i]).toUpperCase(Locale.US);
            if (appendString.length() == 1)hexString.append("0");
            hexString.append(appendString);
            if (i != publicKey.length - 1) hexString.append(":");
        }
        return hexString.toString();
    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }
}

fun getSelfSign(context: Context): String {
    val packageManager = context.packageManager
    val signatures = PackageInfoCompat.getSignatures(packageManager, context.packageName)
    val bytes = signatures[0].toByteArray()
    val messageDigest = MessageDigest.getInstance("SHA1")
    val publicKey: ByteArray = messageDigest.digest(bytes)
    val hexString = StringBuilder()
    for (i in publicKey.indices) {
        val appendString = Integer.toHexString(0xFF and publicKey[i].toInt())
            .toUpperCase(Locale.US)
        if (appendString.length == 1) hexString.append("0")
        hexString.append(appendString)
        if (i != publicKey.size - 1) hexString.append(":")
    }
    return hexString.toString()
}