how to set setOnClickListener for AutoCompleteTextView?

There are different click listeners in AutoCompleteTextView.

The first way is in the layout xml, you can define the onCLick attribute, with the function that you want to be called, in the example below, clicked.

<AutoCompleteTextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/spinner"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:onClick="clicked" />

Then, in your activity, you define the function clicked.

public void clicked(View v) { 
  // on click do ..
} 

Or you can set it directly in your code:

ACTV.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        finish();
    }
});

If you want to set the click listener when the user clicks in an item in the dropdown list there is another method, the setOnItemClickListener.

ACTV.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick (AdapterView<?> parent, View view, int position, long id) {
        //... your stuff
    }
})

And you have a last option, to set the click listener when the user actually selects an item in the dropdown list using setOnItemSelectedListener.

ACTV.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    @Override
    public void onItemSelected (AdapterView<?> parent, View view, int position, long id) {
        //... your stuff
    }
    @Override
    public void onNothingSelected (AdapterView<?> parent) {
        //... your stuff
    }
})

References:

http://developer.android.com/reference/android/widget/AutoCompleteTextView.html

Good luck!

You need to create Custom Adapter and assign OnClick event to the view in getView()