import?android.content.Context;

import?android.graphics.Canvas;

import?android.graphics.drawable.Drawable;

import?android.util.AttributeSet;

import?android.widget.ImageView;

public?classSubjectImageViewextendsImageView{

publicSubjectImageView(Contextcontext,AttributeSetattrs)?{

super(context,attrs);

//TODOAuto-generated?constructor?stub

????}

@Override

protectedvoidonMeasure(intwidthMeasureSpec,intheightMeasureSpec)?{

//獲取真實的圖片

Drawabledrawable=getDrawable();

if(drawable!=null){

//獲取真實的寬

intwidth=drawable.getMinimumWidth();

//獲取真實的高?

intheight=drawable.getMinimumHeight();

//計算寬和高的比例?

floatscale=?(float)width/height;

//獲取測量寬的規(guī)則

intwithsize=MeasureSpec.getSize(widthMeasureSpec);

//按照比例計算高的測量規(guī)則?

intheightsize=?(int)?(withsize/scale);

//設置高的測量規(guī)則?第一個值是按照比例計算的高?第二個參數(shù)是測量模式?精確

heightMeasureSpec=MeasureSpec.makeMeasureSpec(heightsize,MeasureSpec.EXACTLY);

????????}

super.onMeasure(widthMeasureSpec,heightMeasureSpec);

????}