我想使用的getWidth（）/ getHeight（）都会让我的XML-布局的宽度/高度。 我读书，我必须这样做，在的方法OnSizeChanged（），否则我会得到0 （Android:获取屏幕分辨率/像素的整数值的）。

I want to use getWidth()/getHeight() to get width/height of my XML-Layout. I read I have to do it in the method onSizeChanged() otherwise I will get 0 ( Android: Get the screen resolution / pixels as integer values ).

不过，我想这样做在一个类中已经延伸活动。 因此，我认为这是不可能让同一个类扩展视图。

But I want to do it in a class already extending Activity. So I think it's not possible let the same class extending View.

public class MyClass extends Activity {

    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        ViewGroup xml_layout = (ViewGroup) findViewById(R.id.layout_id);  
        TextView tv = new TextView(this);  
        tv = (TextView) findViewById(R.id.text_view);  
        int layout_height = xml_layout.getHeight();  
        int layout_width = xml_layout.getWidth();
    }  

    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        //Error, because I need to use extends View for class, but I can't do it because I also need extends Activity to use onCreate
    }
}

如果我用MyClass的延伸活动，我可以使用的onCreate但不能onSizeChanged。 如果我使用MyClass的扩展视图我可以使用onSizeChangedbut没有的onCreate。

If I use MyClass extends Activity I can use onCreate but not onSizeChanged. If I use MyClass extends View I can use onSizeChangedbut not onCreate.

我该如何解决这个问题呢？

How can I solve the problem?

推荐答案

你不必创建一个 customView 来获取其高度和宽度。您可以添加OnLayoutChangedListener（description这里）的观点，其宽度/你想要的高度，然后基本上得到了onLayoutChanged方法的价值，像这样

You dont have to create a customView to get its height and width. You can add an OnLayoutChangedListener (description here) to the view whose width/height you want, and then essentially get the values in the onLayoutChanged method, like so

View myView = findViewById(R.id.my_view);
myView.addOnLayoutChangeListener(new OnLayoutChangeListener() {

        @Override
        public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight,
                int oldBottom) {
            // its possible that the layout is not complete in which case
            // we will get all zero values for the positions, so ignore the event
            if (left == 0 && top == 0 && right == 0 && bottom == 0) {
                return;
            }

           // Do what you need to do with the height/width since they are now set
        }
    });

这样做的原因是因为次绘制后才布局完成。然后，系统将走下视图层次结构树绘制之前，测量每个视图的宽度/高度。

The reason for this is because views are drawn only after the layout is complete. The system then walks down the view heirarchy tree to measure the width/height of each view before drawing them.