我知道这个问题已经得到了回答，但以下是我如何实现类似的东西:

Intent intent = getPackageManager().getLaunchIntentForPackage("com.package.name");
if (intent != null) {
    // We found the activity now start the activity
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
} else {
    // Bring user to the market or let them choose an app?
    intent = new Intent(Intent.ACTION_VIEW);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.setData(Uri.parse("market://details?id=" + "com.package.name"));
    startActivity(intent);
}

更好的方法是:

public void startNewActivity(Context context, String packageName) {
    Intent intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent != null) {
        // We found the activity now start the activity
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    } else {
        // Bring user to the market or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setData(Uri.parse("market://details?id=" + packageName));
        context.startActivity(intent);
    }
}

删除重复代码:

public void startNewActivity(Context context, String packageName) {
    Intent intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent == null) {
        // Bring user to the market or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);
        intent.setData(Uri.parse("market://details?id=" + packageName));
    }
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(intent);
}

如果你想打开另一个应用程序的特定活动，我们可以使用这个。

Intent intent = new Intent(Intent.ACTION_MAIN, null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
final ComponentName cn = new ComponentName("com.android.settings", "com.android.settings.fuelgauge.PowerUsageSummary");
intent.setComponent(cn);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
try 
{
    startActivity(intent)
}catch(ActivityNotFoundException e){
    Toast.makeText(context,"Activity Not Found",Toast.LENGTH_SHORT).show()
}

如果你必须需要其他应用程序，你可以显示一个对话框，而不是显示Toast。使用对话框，你可以把用户带到Play-Store下载所需的应用程序。

我知道这个问题已经得到了回答，但以下是我如何实现类似的东西:

Intent intent = getPackageManager().getLaunchIntentForPackage("com.package.name");
if (intent != null) {
    // We found the activity now start the activity
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
} else {
    // Bring user to the market or let them choose an app?
    intent = new Intent(Intent.ACTION_VIEW);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.setData(Uri.parse("market://details?id=" + "com.package.name"));
    startActivity(intent);
}

更好的方法是:

public void startNewActivity(Context context, String packageName) {
    Intent intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent != null) {
        // We found the activity now start the activity
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    } else {
        // Bring user to the market or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setData(Uri.parse("market://details?id=" + packageName));
        context.startActivity(intent);
    }
}

删除重复代码:

public void startNewActivity(Context context, String packageName) {
    Intent intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent == null) {
        // Bring user to the market or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);
        intent.setData(Uri.parse("market://details?id=" + packageName));
    }
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(intent);
}

如果您不知道主要活动，那么可以使用包名来启动应用程序。

Intent launchIntent = getPackageManager().getLaunchIntentForPackage("com.package.address");
if (launchIntent != null) { 
    startActivity(launchIntent);//null pointer check in case package name was not found
}

private fun openOtherApp() {
        val sendIntent = packageManager.getLaunchIntentForPackage("org.mab.dhyanaqrscanner")
        startActivity(sendIntent)
        finishAffinity()
    }

// in onCreate method
String appName = "Gmail";
String packageName = "com.google.android.gm";
openApp(context, appName, packageName);

public static void openApp(Context context, String appName, String packageName) {
    if (isAppInstalled(context, packageName))
        if (isAppEnabled(context, packageName))
            context.startActivity(context.getPackageManager().getLaunchIntentForPackage(packageName));
        else Toast.makeText(context, appName + " app is not enabled.", Toast.LENGTH_SHORT).show();
    else Toast.makeText(context, appName + " app is not installed.", Toast.LENGTH_SHORT).show();
}

private static boolean isAppInstalled(Context context, String packageName) {
    PackageManager pm = context.getPackageManager();
    try {
        pm.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES);
        return true;
    } catch (PackageManager.NameNotFoundException ignored) {
    }
    return false;
}

private static boolean isAppEnabled(Context context, String packageName) {
    boolean appStatus = false;
    try {
        ApplicationInfo ai = context.getPackageManager().getApplicationInfo(packageName, 0);
        if (ai != null) {
            appStatus = ai.enabled;
        }
    } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
    }
    return appStatus;
}