就写这个。

XML代码

<TextView
        android:id="@+id/appversion"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />

初始化textview的变量

TextView appversion;

将textview id设置为变量

appversion = findViewById(R.id.appversion);

这是显示应用程序版本BuildConfig.version_NAME的主要代码，仅将其用作字符串值

textview.setText("v"+BuildConfig.VERSION_NAME);

第一：

import android.content.pm.PackageManager.NameNotFoundException;

然后使用这个：

PackageInfo pInfo = null;
try {
     pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
} 
catch (NameNotFoundException e) {
     e.printStackTrace();
}

String versionName = pInfo.versionName;

package com.sqisland.android.versionview;

import android.app.Activity;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity {
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TextView textViewversionName = (TextView) findViewById(R.id.text);

    try {
        PackageInfo packageInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
        textViewversionName.setText(packageInfo.versionName);

    }
    catch (PackageManager.NameNotFoundException e) {

    }
  }
}

由于我只需要获取版本代码并检查应用程序是否更新，如果是，我必须启动play商店以获取更新的应用程序。我是这样做的。

public class CheckForUpdate {

    public static final String ACTION_APP_VERSION_CHECK = "app-version-check";

    public static void launchPlayStoreApp(Context context)
    {
        // getPackageName() from Context or Activity object
        final String appPackageName = context.getPackageName();
        try {
            context.startActivity(new Intent(Intent.ACTION_VIEW,
                                  Uri.parse("market://details?id=" + appPackageName)));
        }
        catch (android.content.ActivityNotFoundException anfe) {
            context.startActivity(new Intent(Intent.ACTION_VIEW,
                                  Uri.parse("https://play.google.com/store/apps/details?id=" +
                                             appPackageName)));
        }
    }

    public static int getRemoteVersionNumber(Context context)
    {
        int versionCode = 0;
        try {
            PackageInfo pInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
            String version = pInfo.versionName;
            versionCode = pInfo.versionCode;
        }
        catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return versionCode;
    }
}

然后，我通过创建一个util类，使用共享首选项保存了版本代码。

public class PreferenceUtils {

    // This is for version code
    private  final String APP_VERSION_CODE = "APP_VERSION_CODE";
    private  SharedPreferences sharedPreferencesAppVersionCode;
    private SharedPreferences.Editor editorAppVersionCode;
    private static Context mContext;

    public PreferenceUtils(Context context)
    {
        this.mContext = context;
        // This is for the app versioncode
        sharedPreferencesAppVersionCode = mContext.getSharedPreferences(APP_VERSION_CODE,MODE_PRIVATE);
        editorAppVersionCode = sharedPreferencesAppVersionCode.edit();
    }

    public void createAppVersionCode(int versionCode) {

        editorAppVersionCode.putInt(APP_VERSION_CODE, versionCode);
        editorAppVersionCode.apply();
    }

    public int getAppVersionCode()
    {
        return sharedPreferencesAppVersionCode.getInt(APP_VERSION_CODE,0); // As the default version code is 0
    }
}

这是一个干净的解决方案，基于scottyab（由哈维编辑）的解决方案。它显示了如果方法没有提供上下文，如何首先获取上下文。此外，它使用多行而不是每行调用多个方法。这使您在调试应用程序时更容易。

Context context = getApplicationContext(); // or activity.getApplicationContext()
PackageManager packageManager = context.getPackageManager();
String packageName = context.getPackageName();

String myVersionName = "not available"; // initialize String

try {
    myVersionName = packageManager.getPackageInfo(packageName, 0).versionName;
} catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
}

现在您在StringmyVersionName中收到了版本名，您可以将其设置为TextView或任何您喜欢的内容。。

// Set the version name to a TextView
TextView tvVersionName = (TextView) findViewById(R.id.tv_versionName);
tvVersionName.setText(myVersionName);

try {
    PackageInfo packageInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
    String versionName = packageInfo.versionName;
    int versionCode = packageInfo.versionCode;
    //binding.tvVersionCode.setText("v" + packageInfo.versionName);
}
catch (PackageManager.NameNotFoundException e) {
    e.printStackTrace();
}