如果未安装应用程序，如何检查是否已从我的应用程序安装了应用程序？

Question

I have an application... on button click in my application i need to check whether a particular app is installed in the phone or not..If the application is not installed it should redirect to play store.

How can i do that please help?

public class Example extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //Put the package name here...
        boolean installed  =   appInstalledOrNot("com.Ch.Example.pack");  
        if(installed) {
            //This intent will help you to launch if the package is already installed
            Intent LaunchIntent = getPackageManager()
                .getLaunchIntentForPackage("com.Ch.Example.pack");
            startActivity(LaunchIntent);

            System.out.println("App already installed on your phone");        
        }
        else {
            System.out.println("App is not installed on your phone");
        }
    }

    private boolean appInstalledOrNot(String uri) {
        PackageManager pm = getPackageManager();
        boolean app_installed = false;
        try {
            pm.getPackageInfo(uri, PackageManager.GET_ACTIVITIES);
            app_installed = true;
        }
        catch (PackageManager.NameNotFoundException e) {
            app_installed = false;
        }
        return app_installed ;
    }
}

Does the above example work for checking whether an app is installed or not my my application.

Answer 1

To check whether an app is installed in the device use following method and params GooglePlayStorePackageNameOld & GooglePlayStorePackageNameNew both holds the package names of apps

private static final String GooglePlayStorePackageNameOld = "com.google.market";
private static final String GooglePlayStorePackageNameNew = "com.android.vending";

use and modify the following method accordingly to check if the app is presently installed in the device or not

public boolean isAppInstalled() {
            PackageManager packageManager = getApplication().getPackageManager();
            List<PackageInfo> packages = packageManager
                    .getInstalledPackages(PackageManager.GET_UNINSTALLED_PACKAGES);
            for (PackageInfo packageInfo : packages) {
                if (packageInfo.packageName.equals(GooglePlayStorePackageNameOld)
                        || packageInfo.packageName
                                .equals(GooglePlayStorePackageNameNew)) {
                    googlePlayStoreInstalled = true;
                    break;
                } else {
                    googlePlayStoreInstalled = false;
                }
            }
            return googlePlayStoreInstalled;
        }

and to navigate user to a particular Play Store link use the following code

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

EDIT According to your code

Intent LaunchIntent = getPackageManager()
                .getLaunchIntentForPackage("com.Ch.Example.pack");
            startActivity(LaunchIntent);

will launch the app which has the package name com.Ch.Example.pack

Answer 2

The way you check if the app is installed is a standard way. To redirect to playStore you can use the following snippet

private goToPlayStore(String packageName) {
  Intent marketIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=" + packageName))
  startActivity(intent);
}

also with respect to the comment, you should check first if the market is installed, the package name should be com.android.vending . This code will throw an exception if market is not available.