下面是我的例子，如果有人觉得有用，我就从我的应用程序中启动条形码/QR码扫描仪

Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.setPackage("com.google.zxing.client.android");

try 
{
    startActivityForResult(intent, SCAN_REQUEST_CODE);
} 
catch (ActivityNotFoundException e) 
{
    //implement prompt dialog asking user to download the package
    AlertDialog.Builder downloadDialog = new AlertDialog.Builder(this);
    downloadDialog.setTitle(stringTitle);
    downloadDialog.setMessage(stringMessage);
    downloadDialog.setPositiveButton("yes",
            new DialogInterface.OnClickListener() 
            {
                public void onClick(DialogInterface dialogInterface, int i) 
                {
                    Uri uri = Uri.parse("market://search?q=pname:com.google.zxing.client.android");
                    Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                    try
                    {
                        myActivity.this.startActivity(intent);
                    }
                    catch (ActivityNotFoundException e)
                    {
                        Dialogs.this.showAlert("ERROR", "Google Play Market not found!");
                    }
                }
            });
    downloadDialog.setNegativeButton("no",
            new DialogInterface.OnClickListener() 
            {
                public void onClick(DialogInterface dialog, int i) 
                {
                    dialog.dismiss();
                }
            });
    downloadDialog.show();
}

试试下面的代码:

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setComponent(new ComponentName("package_name", "Class_name"));
if (intent.resolveActivity(getPackageManager()) != null) 
{
   startActivity(intent);
}

下面是我的例子，如果有人觉得有用，我就从我的应用程序中启动条形码/QR码扫描仪

Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.setPackage("com.google.zxing.client.android");

try 
{
    startActivityForResult(intent, SCAN_REQUEST_CODE);
} 
catch (ActivityNotFoundException e) 
{
    //implement prompt dialog asking user to download the package
    AlertDialog.Builder downloadDialog = new AlertDialog.Builder(this);
    downloadDialog.setTitle(stringTitle);
    downloadDialog.setMessage(stringMessage);
    downloadDialog.setPositiveButton("yes",
            new DialogInterface.OnClickListener() 
            {
                public void onClick(DialogInterface dialogInterface, int i) 
                {
                    Uri uri = Uri.parse("market://search?q=pname:com.google.zxing.client.android");
                    Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                    try
                    {
                        myActivity.this.startActivity(intent);
                    }
                    catch (ActivityNotFoundException e)
                    {
                        Dialogs.this.showAlert("ERROR", "Google Play Market not found!");
                    }
                }
            });
    downloadDialog.setNegativeButton("no",
            new DialogInterface.OnClickListener() 
            {
                public void onClick(DialogInterface dialog, int i) 
                {
                    dialog.dismiss();
                }
            });
    downloadDialog.show();
}

这将涵盖所有场景

1.获取包的意图

2.如果意图为空重定向用户到播放商店

3.如果打开playstore存在问题，那么它将在默认浏览器上打开。

var intent = activity!!.packageManager.getLaunchIntentForPackage("com.google.android.youtube")

          if (intent == null) {
            if (intent == null) {
                    intent = try {
                        Intent(Intent.ACTION_VIEW, Uri.parse("market://details?id=com.google.android.youtube"))
                    } catch (e: Exception) {
                        Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=com.google.android.youtube"))
                    }
                }
             startActivity(intent)

对于Android 11 (API级别30)或更高，在AndroidManifest.xml中，

<queries>
    <package android:name="com.google.android.youtube" />
    <package android:name="com.example.app" />
</queries>

或者我们可以允许所有的包(不推荐)

<uses-permission android:name="android.permission.QUERY_ALL_PACKAGES" tools:ignore="QueryAllPackagesPermission" />

参考文献

Android上的包可见性过滤

声明包可见性需求

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
}

启动新活动的步骤如下:

1.获取包的意图

2.如果意图为空重定向用户到播放商店

3.如果意图不为空，打开活动

public void launchNewActivity(Context context, String packageName) {
    Intent intent = null;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.CUPCAKE) {
        intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    }
    if (intent == null) {
        try {
            intent = new Intent(Intent.ACTION_VIEW);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent.setData(Uri.parse("market://details?id=" + packageName));
            context.startActivity(intent);
        } catch (android.content.ActivityNotFoundException anfe) {
            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=" + packageName)));
        }
    } else {
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    }
}