Android 自定义imageview图片高度固定大小宽度按比例自适应

package com.common.common.wediget;


import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.NinePatchDrawable;
import android.util.AttributeSet;
import android.view.ViewGroup.LayoutParams;
import android.widget.ImageView;


public class AdaptiveImageView_Width_Wrap_content extends ImageView {


// 控件默认长、宽


private int defaultWidth = 0;


private int defaultHeight = 0;


// 比例


private float scale = 0;


public AdaptiveImageView_Width_Wrap_content(Context context) {


super(context);


}


public AdaptiveImageView_Width_Wrap_content(Context context, AttributeSet attrs) {


super(context, attrs);


}


public AdaptiveImageView_Width_Wrap_content(Context context, AttributeSet attrs, int defStyle) {


super(context, attrs, defStyle);


}


@Override
protected void onDraw(Canvas canvas) {


Drawable drawable = getDrawable();


if (drawable == null) {


return;


}


if (getWidth() == 0 || getHeight() == 0) {


return;


}


this.measure(0, 0);


if (drawable.getClass() == NinePatchDrawable.class)


return;


Bitmap b = ((BitmapDrawable) drawable).getBitmap();


Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);


if (bitmap.getWidth() == 0 || bitmap.getHeight() == 0) {


return;


}


if (defaultWidth == 0) {


defaultWidth = getWidth();


}


if (defaultHeight == 0) {


defaultHeight = getHeight();


}


scale = (float) defaultHeight / (float) bitmap.getHeight();


defaultWidth = Math.round(bitmap.getWidth() * scale);


LayoutParams params = this.getLayoutParams();


params.width = defaultWidth;


params.height = defaultHeight;


this.setLayoutParams(params);


super.onDraw(canvas);


}


}