How to get the width and height of an android.widg

问题:

╔══════════════════════════════════════════════╗   ^
║ ImageView    ╔══════════════╗                ║   |
║              ║              ║                ║   |
║              ║ Actual image ║                ║   |
║              ║              ║                ║   |60px height of ImageView
║              ║              ║                ║   |
║              ║              ║                ║   |
║              ╚══════════════╝                ║   |
╚══════════════════════════════════════════════╝   
<------------------------------------------------>
                   90px width of ImageView

I have an image view with some default height and width, images are stored in db and I want to scale Image according to Imageview height width. As I don\'t want it give default values because when ever I change it\'s height and width I also have to change it in code.

I am trying to get the height and width of ImageView but 0 is returned to me in both cases.

int height = ((ImageView) v.findViewById(R.id.img_ItemView)).getHeight();

this returns me 0 even it has default height and width

回答1:

My answer on this question might help you:

int finalHeight, finalWidth;
final ImageView iv = (ImageView)findViewById(R.id.scaled_image);
final TextView tv = (TextView)findViewById(R.id.size_label);
ViewTreeObserver vto = iv.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
    public boolean onPreDraw() {
        iv.getViewTreeObserver().removeOnPreDrawListener(this);
        finalHeight = iv.getMeasuredHeight();
        finalWidth = iv.getMeasuredWidth();
        tv.setText(\"Height: \" + finalHeight + \" Width: \" + finalWidth);
        return true;
    }
});

You can then add your image scaling work from within the onPreDraw() method.

回答2:

I just set this property and now Android OS is taking care of every thing.

android:adjustViewBounds=\"true\"

Use this in your layout.xml where you have planted your ImageView :D

回答3:

I could get image width and height by its drawable;

int width = imgView.getDrawable().getIntrinsicWidth();
int height = imgView.getDrawable().getIntrinsicHeight();

回答4:

The reason the ImageView\'s dimentions are 0 is because when you are querying them, the view still haven\'t performed the layout and measure steps. You only told the view how it would \"behave\" in the layout, but it still didn\'t calculated where to put each view.

How do you decide the size to give to the image view? Can\'t you simply use one of the scaling options natively implemented?

回答5:

Post to the UI thread works for me.

final ImageView iv = (ImageView)findViewById(R.id.scaled_image);

iv.post(new Runnable() {
            @Override
            public void run() {
                int width = iv.getMeasuredWidth();
                int height = iv.getMeasuredHeight();

            }
});

回答6:

I think you can let the Android OS take care of this for you. Set the scale type on the ImageView to fitXY and the image it displays will be sized to fit the current size of the view.

<ImageView 
    android:layout_width=\"90px\" 
    android:layout_height=\"60px\"
    android:scaleType=\"fitXY\" />

回答7:

your xml file :

 <ImageView android:id=\"@+id/imageView\"
               android:layout_width=\"wrap_content\"
               android:layout_height=\"wrap_content\"
               android:src=\"@drawable/image\"
               android:scaleType=\"fitXY\"
               android:adjustViewBounds=\"true\"/>

your java file:

ImageView imageView = (ImageView)findViewById(R.id.imageView);
     int width = imageView.getDrawable().getIntrinsicWidth();
     int   height = imageView.getDrawable().getIntrinsicHeight();

回答8:

The simplest way is to get the width and height of an ImageView in onWindowFocusChanged method of the activity

 @Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);

    height = mImageView.getHeight();
    width = mImageView.getWidth();

}

回答9:

If you have created multiple images dynamically than try this one:

// initialize your images array

private ImageView myImages[] = new ImageView[your_array_length];

// create programatically and add to parent view

 for (int i = 0; i < your_array_length; i++) {
                myImages[i] = new ImageView(this);
                myImages[i].setId(i + 1);
                myImages[i].setBackgroundResource(your_array[i]);
                RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
                        frontWidth[i], frontHeight[i]);
                ((MarginLayoutParams) params).setMargins(frontX_axis[i],
                        frontY_axis[i], 0, 0);
                myImages[i].setAdjustViewBounds(true);
                myImages[i].setLayoutParams(params);

                if (getIntent() != null && i != your_array,length) {
                    final int j = i;
                    myImages[j].getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
                        public boolean onPreDraw() {
                            myImages[j].getViewTreeObserver().removeOnPreDrawListener(this);
                    finalHeight = myImages[j].getMeasuredHeight();
                        finalWidth = myImages[j].getMeasuredWidth();
                    your_textview.setText(\"Height: \" + finalHeight + \" Width: \" + finalWidth);
                            return true;
                        }
                    });
                }
                your_parent_layout.addView(myImages[i], params);
            }

// That\'s it. Happy Coding.

回答10:

my friend by this u are not getting height of image stored in db.but you are getting view height.for getting height of image u have to create bitmap from db,s image.and than u can fetch height and width of imageview