CODEWITHSUNDEEP
androidandroid-layout
S.J. Lim
S.J. Lim

Reputation: 3165

Why linearlayout's size -1?

I'm trying to get linearlayout's size.

I tested as following code.

But I just get value -1 (linearlayout's width).

How to get correct size?

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/mainLayout"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">

    <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Hello World, MyActivity"
            />
</LinearLayout>



package com.example.LayoutSize;

import android.app.Activity;
import android.os.Bundle;
import android.view.ViewGroup;
import android.widget.LinearLayout;

public class MyActivity extends Activity {
    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        LinearLayout linearLayout = (LinearLayout) findViewById(R.id.mainLayout);
        ViewGroup.LayoutParams layoutParams = linearLayout.getLayoutParams();

        System.out.printf("linearLayout width : %d", layoutParams.width);

    }
}

Upvotes: 0

Views: 49

Answers (2)

Amulya Khare
Amulya Khare

Reputation: 7698

The reason you get -1 is because the width parameter is set to MatchParent which has a value -1.

To get the size of a layout, your should be using getWidth() or getMeasuredWidth() methods. However, these methods won't give you a meaningful answer until the view has been measured. Read about how android draws views here.

You can get the correct size, by overriding the onWindowFocusChanged() as mentioned in this thread.

Alternatively, (hacky solution), you could do this:

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    final LinearLayout linearLayout = (LinearLayout) findViewById(R.id.mainLayout);
    linearLayout.post(new Runnable() {
        @Override
        public void run() {
            System.out.printf("linearLayout width : %d", linearLayout.getMeasuredWidth());
        }
    });
}

Upvotes: 1

c0ming
c0ming

Reputation: 3543

public static final int MATCH_PARENT = -1;

Upvotes: 0

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