how to find the height and width of the image view when it is aligned center in android app?

问题

Here is my snippet of code

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/framelayouts"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_gravity="center"
     >

    <ImageView
        android:id="@+id/imageviews"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_gravity="center"
        android:src="@drawable/ic_launcher" />

</FrameLayout>

now am able to get the image at center .

Problem:

Here Problem is i am getting some un used space top and bottom, how can i find the height of the unused space or height of the image or only the imageheight ?

Screenshot:

回答1:

private void getImageViewDimension() {
    // TODO Auto-generated method stub
    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {

        int actualImgWidth = mDeviceWidth -  mImgView.getX();
        int actualImgHeight = mDeviceHeight -  mImgView.getY();


        Toast.makeText(getApplicationContext(), "actualImgWidth ,actualImgHeight:"    +actualImgWidth +","+actualImgHeight ,
                    Toast.LENGTH_SHORT).show();

        int Width = mImgView.getWidth();
        int Height = mImgView.getHeight();

        }
    }, 10L);
}

回答2:

You can find Image height using below code.

final ImageView layout = (ImageView) findViewById(R.id.imageviews);
    ViewTreeObserver vto = layout.getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            layout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
            int height = layout.getMeasuredHeight();
            if (height > 0) {
                Log.i("TAG", "height : " + height);
            }
        }
    });

回答3:

You can calculate the height and width of the Imageview using ViewTreeObserver. Try this sample app.

public class MainActivity extends Activity {

    int finalHeight, finalWidth;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final ImageView iv = (ImageView)findViewById(R.id.imageviews);
        ViewTreeObserver vto = iv.getViewTreeObserver();
        vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
            public boolean onPreDraw() {
                iv.getViewTreeObserver().removeOnPreDrawListener(this);
                finalHeight = iv.getMeasuredHeight();
                finalWidth = iv.getMeasuredWidth();
                Log.i("DIMEN", "Height: " + finalHeight + " Width: " + finalWidth);
                return true;
            }
        });
    }
}

But since you are using fillparent for your ImageView, you will get the entire width as the result.

来源：https://stackoverflow.com/questions/26992000/how-to-find-the-height-and-width-of-the-image-view-when-it-is-aligned-center-in

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android

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imageview