BitmapManager

package com.k1.media;

import java.io.IOException;
import java.io.InputStream;

import android.app.Activity;
import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;

public class BitmapManager {
//从assets中读取图片
    public static Bitmap getImageFromAssetsFile(Context context, String fileName) {
        String url = "PhonePage/image/";
        Bitmap image = null;
        AssetManager am = context.getResources().getAssets();
        try {
            InputStream is = am.open(url + fileName + ".png");
            image = BitmapFactory.decodeStream(is);
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return image;

    }
//设置圆形图片
    public static Bitmap makeRoundCorner(Bitmap bitmap) {
        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        int left = 0, top = 0, right = width, bottom = height;
        float roundPx = height / 2;
        if (width > height) {
            left = (width - height) / 2;
            top = 0;
            right = left + height;
            bottom = height;
        } else if (height > width) {
            left = 0;
            top = (height - width) / 2;
            right = width;
            bottom = top + width;
            roundPx = width / 2;
        }

        Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        int color = 0xff424242;
        Paint paint = new Paint();
        Rect rect = new Rect(left, top, right, bottom);
        RectF rectF = new RectF(rect);

        paint.setAntiAlias(true);
        canvas.drawARGB(0, 0, 0, 0);
        paint.setColor(color);
        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
        paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, paint);
        return output;
    }
}