Cannot start new Intent by setClassName with different package in Android

Question

I want to start a new Intent dynamically. Therefore setClassName seems the best choice.

First, I define 3 activity in Manifest

Answer 1

intent.setClassName(Act.this, Act1.class);

Answer 2

The first param is the applicationId located in the build.gradle file

The second param is full path to of the class with its package. for example: intentObj.setClassName("applicatioId", "com.youCompany.yourAppName.YourClassName")

Answer 3

Use this code and you'll be fine.

Intent intent = new Intent();
String resourcePackageName = getResources().getResourcePackageName(R.string.some_defined_resource);
intent.setClassName(getApplicationContext().getPackageName(),resourcePackageName + ".SubPackageName[/if any/].ClassName");
startActivity(intent);

Answer 4

Follow the syntax to write setClassName() method:

 setClassName( pkgName, className ) 

Answer 5

You can use the following method to create the intent in the package context:

    Intent intent = new Intent(this, MyActivity.class);
    intent.setAction(Intent.ACTION_VIEW);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);

This way you keep on generic code.

HTH

Answer 6

setClassName take a Package Context as first param setClassName(Context packageContext, String className):

Intent intent = new Intent();
if(index == 0) {
  intent.setClassName("com.example.pkg1", "com.example.pkg1.Act1");
} else {
  intent.setClassName("com.example.pkg1", "com.example.pkg1.Act2");
  startActivity(intent);
}

and in

<activity android:name="com.example.pkg2.Act" />
<activity android:name="com.example.pkg1.Act1" />
<activity android:name="com.example.pkg1.Act2" />

or you try this :

if(index == 0) {
  Intent intent = new Intent(Intent.ACTION_MAIN)
    .addCategory(intent.CATEGORY_LAUNCHER)
    .setClassName("com.example.pkg1", "com.example.pkg1.Act1")
    .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
    .addFlags(Intent.FLAG_FROM_BACKGROUND)
    .setComponent(new ComponentName("com.example.pkg1", "com.example.pkg1.Act1"));
  getApplicationContext().startActivity(intent);
} else {
  Intent intent  = new Intent(Intent.ACTION_MAIN)
    .addCategory(intent.CATEGORY_LAUNCHER)
    .setClassName("com.example.pkg1", "com.example.pkg1.Act2")
    .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
    .addFlags(Intent.FLAG_FROM_BACKGROUND)
    .setComponent(new ComponentName("com.example.pkg1", "com.example.pkg1.Act2"));
  getApplicationContext().startActivity(intent);
}