小賴的實戰記錄

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

public class ResizableImageView extends ImageView {

    public ResizableImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override 
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){
         Drawable d = getDrawable();

         if(d!=null){
                 // ceil not round - avoid thin vertical gaps along the left/right edges
                 int width = MeasureSpec.getSize(widthMeasureSpec);
                 int height = (int) Math.ceil((float) width * (float) d.getIntrinsicHeight() / (float) d.getIntrinsicWidth());
                 setMeasuredDimension(width, height);
         }else{
                 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
         }
    }

}

	<LinearLayout
	    android:layout_width="315dp"
	    android:layout_height="wrap_content"
	    android:layout_gravity="center"
	    android:layout_margin="16dp"
	    android:orientation="vertical">
	    
	    <com.hotai.app.control.ResizableImageView
	        android:id="@+id/iv_img"
	        android:layout_width="match_parent"
	        android:layout_height="wrap_content"
	        android:clickable="true"/>
	</LinearLayout>