content view width and height

问题:

I am using below steps to know the width and height of contentview on my display screen

ContentViewWidth = getWindow().findViewById(Window.ID_ANDROID_CONTENT).getWidth();
ContentViewHeight = getWindow().findViewById(Window.ID_ANDROID_CONTENT).getHeight();

but this method doesn't work inside onCreate or onResume and if I am using these steps inside onWindowFocusChanged I get force close error on my phone

Please help me how can I get the content view of my display screen. Content view is excluding statusbar and titlebar dimensions

回答1:

I use the following technique - post a runnable from onCreate() that will be executed when the view has been created:

    contentView = findViewById(android.R.id.content);
    contentView.post(new Runnable()
    {
        public void run()
        {
            contentHeight = contentView.getHeight();
        }
    });

This code will run on the main UI thread, after onCreate() has finished.

---

If you are trying to get the height of the content view itself, you need to subtract the padding from the height - this is because Android 2.x lays out the views differently to 4.x.

contentHeight = contentView.getHeight() - contentView.getTopPadding();

回答2:

Here's what I did in my activity to figure out the content layout of a particular view child that I knew stretched end-to-end on the screen (a webview in this case):

First, inherit from OnGlobalLayoutListener:

public class ContainerActivity extends Activity implements ViewTreeObserver.OnGlobalLayoutListener {
...

Next, implement onGlobalLayout method of listener's interface (note I do some pixel calcs that pertain to figuring out the medium-zoom dip :

@Override
public void onGlobalLayout() {
    int nH = this.mWebView.getHeight();
    int nW = this.mWebView.getWidth();

    if (nH > 0 && nW > 0)
    {
        DisplayMetrics oMetrics = new DisplayMetrics();

        this.getWindowManager().getDefaultDisplay().getMetrics(oMetrics); 

        nH = (nH * DisplayMetrics.DENSITY_DEFAULT) / oMetrics.densityDpi;
        nW = (nW * DisplayMetrics.DENSITY_DEFAULT) / oMetrics.densityDpi;

        // do something with nH and nW                  

        this.mWebView.getViewTreeObserver().removeGlobalOnLayoutListener
            ( this
            );

            ...         
    }
}

Finally, make sure to tell the view element (mWebView in this case) inside onCreate() that you're listening to layout events:

this.setContentView(this.mWebView = new WebView(this));

this.mWebView.getViewTreeObserver().addOnGlobalLayoutListener
    ( this
    );

This approach works for older android versions. I believe ics+ has a layout listener for each view you can bind to, and as such, would be used in a similar way.

回答3:

Rect rectangle = new Rect();
Window window = getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectangle);
int contentHeight = window.findViewById(Window.ID_ANDROID_CONTENT).getHeight();
int contentWidth = window.findViewById(Window.ID_ANDROID_CONTENT).getWidth();