Center message in android dialog box

Building off of Chase's answer, here's how to also center the title. I think this is the easiest way. Why android doesn't center by default or make it a simple constructor param is beyond me.

AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setTitle("My Title");
builder.setMessage("My message");
builder.setPositiveButton("OK", listener);
AlertDialog dialog = builder.show();

// Must call show() prior to fetching views
TextView messageView = (TextView)dialog.findViewById(android.R.id.message);
messageView.setGravity(Gravity.CENTER);

TextView titleView = (TextView)dialog.findViewById(context.getResources().getIdentifier("alertTitle", "id", "android"));
if (titleView != null) {
    titleView.setGravity(Gravity.CENTER);
}

Create your own TextView object and then supply it to popup builder as View:

AlertDialog.Builder popupBuilder = new AlertDialog.Builder(this);
TextView myMsg = new TextView(this);
myMsg.setText("Central");
myMsg.setGravity(Gravity.CENTER_HORIZONTAL);
popupBuilder.setView(myMsg);

You can control all other text parameters (style, color, size ...). To control margins you may programatically create LinearLayout, set LayoutParams, and then put TextView into it.

Of course, you can always set the gravity of the original text view. This allows you to not have to worry about formatting and padding.

For example

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Title");
builder.setMessage("Message");
builder.setPositiveButton("OK", null);
AlertDialog dialog = builder.show();

// Must call show() prior to fetching text view
TextView messageView = (TextView)dialog.findViewById(android.R.id.message);
messageView.setGravity(Gravity.CENTER);