如何检查 zoom.us 和 Slack 应用程序是否安装在 Android 上？

Question

I'm trying to create an app in Android where a user can install zoom.us and Slack apps and run them but I need to check before installation if the app is already installed or not. The problem is I don't know the names of the packages so I can check against them, What would be the name of packages for zoom.us and slack and How would I run them by click of zoom and slack buttons?

public class MainActivity extends AppCompatActivity {

        ImageButton zoom, slack;
        Button installZoom, installSlack;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            // Install zoom
            installZoom = (Button) findViewById(R.id.inst_zoom);
            if (isZoomClientInstalled(getApplicationContext())) {
                installZoom.setEnabled(false);
            } else {
                installZoom.setEnabled(true);

                installZoom.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent();
                        intent.setAction(Intent.ACTION_VIEW);
                        intent.addCategory(Intent.CATEGORY_BROWSABLE);
                        intent.setData(Uri.parse("https://play.google.com/store/apps/details?id=us.zoom.videomeetings"));
                        startActivity(intent);
                    }
                });
            }
            // Run zoom
            zoom = (ImageButton) findViewById(R.id.app_zoom);
            zoom.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {               
                    Toast.makeText(getApplicationContext(), "About to run zoom", Toast.LENGTH_SHORT).show();
                }
            });

            // Install Slack
            installSlack = (Button) findViewById(R.id.inst_slack);
            if (isSlckClientInstalled(getApplicationContext())) {
                installSlack.setEnabled(false);
            } else {
                installSlack.setEnabled(true);

                installSlack.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent();
                        intent.setAction(Intent.ACTION_VIEW);
                        intent.addCategory(Intent.CATEGORY_BROWSABLE);
                        intent.setData(Uri.parse("https://slack.com/downloads/android"));
                        startActivity(intent);
                    }
                });
            }

            // Run Slack
            slack = (ImageButton) findViewById(R.id.app_slack);
            slack.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(getApplicationContext(), "About to run Slack", Toast.LENGTH_SHORT).show();
                }
            });

        }// End of Create();

        // Determine whether the zoom for Android client is installed on this device.
        public boolean isZoomClientInstalled(Context myContext) {
            PackageManager myPackageMgr = myContext.getPackageManager();
            try {
                myPackageMgr.getPackageInfo("???.???.??", PackageManager.GET_ACTIVITIES);
            } catch (PackageManager.NameNotFoundException e) {
                return (false);
            }
            return (true);
        }

        // Determine whether the Slack for Android client is installed on this device.
        public boolean isSlackClientInstalled(Context myContext) {
            PackageManager myPackageMgr = myContext.getPackageManager();
            try {
                myPackageMgr.getPackageInfo("???.???.??", PackageManager.GET_ACTIVITIES);
            } catch (PackageManager.NameNotFoundException e) {
                return (false);
            }
            return (true);
        }

}// End of class

Answer 1

you may find app package by looking into Google Play link

https://play.google.com/store/apps/details?id=com.Slack

com.Slack is package name here. us.zoom.videomeetings for Zoom. Then you just start it with Intent. Try it.

Answer 2

If you know the package name for the app, then you can check that if that app is installed on the device or not.

PACKAGE NAMES:

Zoom.Us : us.zoom.videomeetings Slack : com.Slack

You know the code for it as stated in the comments. By running it you will know if the app is installed on the device or not.

Answer 3

To check if app is installed or not, you need to know the package name of the app you want to check. You can find the package name of the app from Google play store, focus on URL. Id in URL is the package name.

For Example for Zoom.us it is: us.zoom.videomeetings

Since both apps are well established, it is highly unlikely they will update the package name.