How to Start a New Android Activity Using Class Name in a String

How can I start a new android activity using class name in a string?

Here is a code by which you can start activity using the name of the activity

String activityToStart = "com.example.MainActivity";
try {
    Class<?> c = Class.forName(activityToStart);
    Intent intent = new Intent(this, c);
    startActivity(intent);
} catch (ClassNotFoundException ignored) {
}

EDIT

Here class name will be full name of the class with the package name.
For example if your package name will be x.y.z and if you have Activity name called A then the full name of the Activity A will be x.y.z.A.

Android Intents: Start activity using class name from another app that has the same sharedUserId

Its pretty easy since you have the sharedUserId set.

Intent res = new Intent();
String mPackage = "com.your.package";
String mClass = ".actYouAreLaunching";
res.setComponent(new ComponentName(mPackage,mPackage+mClass));
startActivity(res);

And that's all there is to it. You can add intent extras like you normally would.

Intent and start activity from string

Try this:
startActivity(this, Class.forName(yourStringClass));

Open a new activity from a class string. Class null

When you use Class.forName(className) method, className has to be constructed from your package name and your Class name without the .class extension.

For ro.movieapp.activities.MovieActivity.class your call should be something like this: Class.forName("ro.movieapp.activities.MovieActivity").

That being said, it is a really bad idea to do it because it's an easy source of bugs (your question is a good example). You should keep a reference to your activity's Class inside your Movie object.

My suggestion is to do something like this:

class Movie {

    private Class<?> activityClass;

    public <C extends AppCompatActivity> void setActivityClass(Class<C> activityClass) {
        this.activityClass = activityClass;
    }

    @SuppressWarnings("unchecked")
    public <C extends AppCompatActivity> Class<C> getActivityClass() {
        return (Class<C>) activityClass;
    }
}

...

final Movie movie = new Movie();
movie.setActivityClass(MovieActivity.class);

...

final Intent intent = new Intent(getActivity(), movie.getActivityClass());
startActivity(intent);

Start new activity getting the class by a String

You can load the class using reflection, e.g.:

public startNewActivity(String activityName){
   try {
       Class<?> clazz = Class.forName(getPackageName() +"." +activityName);

       Intent myActivity = new Intent(CurrentClass.this, clazz);
       startActivity(myActivity);

   } catch (Exception e) {
       Log.e("TAG","Error: " +e.getStackTrace());
   }
}

If you provide the full class name (including package name) you don't need the getPackageName() call.

Hope this helps .. Cheers!

Start Activity with New Intent using dynamic class name

You can use java's reflection methods:

Class activityClass = Class.forName("com.something.Zero");

StartActivity from string

Assuming this is the Activity that you are trying to start:

namespace SushiHangover
{
    [Activity(Name = "Resources.biblioteka.SomeActivity", Label = "SomeActivity")]
    public class SomeActivity : Activity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
        }
    }
}

Using the .Net Namespace/Class Name:

var intent = new Intent(this, Type.GetType("SushiHangover.SomeActivity"));
StartActivity(intent);

Using the Java Package/Class Name:

var intent = new Intent(this, Java.Lang.Class.ForName("Resources.biblioteka.SomeActivity"));
StartActivity(intent);