How to align text view with above widget?

My UI contains two elements: a button on top and a textview below the button. The width of the button is set to "wrap_content", so it will change its width when I set different text to the button in the run time. I want to always let the textview align with the button(has the same width), especially the UI is first loaded.

I tried to get width of the button in onGlobalLayout event and set the width of textview, but it seems not work. Can an开发者_开发知识库yone help me?

UPDATE:

I think I might have over simplified my problem. The real UI has lots of widgets (both button and textview in my question) generated by code. So I can't use XML to define them. And because the UI is not totally loaded, I can't use getWidth() the get the real width of the button when I align the text view.

---

I think you should use the Android LayoutParams.

http://developer.android.com/reference/android/view/ViewGroup.LayoutParams.html

In onCreate or in the code where your are setting the text to a button. After setting the text int button you should set the width on textview = width of button using the button's layout params.

---

Make this layout in XML, use RelativeLayout as container for Button and TextView.

Then for the TextView you would specify alignment:

android:layout_alignLeft="@+id/button1" 
android:layout_alignRight="@+id/button1"

thus both its left and right side is aligned to your button.

Note: you can make same also from java code using RelativeLayout.LayoutParams, but it's more complicated than using XML.

---

In case, you do like working in code, this is one sample regarding Button and TextView having same width:

public class MainActivity extends Activity {
    Button mButton;
    TextView mText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);        

        mButton = (Button)findViewById(R.id.button);
        mText = (TextView)findViewById(R.id.text);

        updateUI();
    }

    public void updateUI() {
        int wButton = mButton.getWidth();
        int wText = mText.getWidth();

        if(wButton < wText) {
            mButton.setWidth(wText);
        } else {
            mText.setWidth(wButton);
        }
    }
}

Well, the drawback is you need to call updateUI() everytime you update the text of either control.