final Activity targetActivity = Solo.getCurrentActivity(); // Using Robotium to get current displayed Activity
Toast.makeText(targetActivity, "Hello from Instrumentation", Toast.LENGTH_SHORT).show();

final Activity targetActivity = Solo.getCurrentActivity(); // Using Robotium to get current displayed Activity

LayoutInflater inflater = targetActivity.getLayoutInflater();
View layout = inflater.inflate(test.my.package.R.layout.my_custom_toast, null); // resource is located in test project
TextView text = (TextView) layout.findViewById(test.my.package.R.id.textToShow); // textview within the layout

text.setText("Hello from Instrumentation"); // here I get the NullPointerException

Toast toast = new Toast(targetActivity);
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.setDuration(Toast.LENGTH_LONG);
toast.setView(layout);
toast.show();