android 设置圆角图片实现代码

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/layout"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
</linearlayout>
package com.test.demo;

import android.app.activity;
import android.graphics.bitmap;
import android.graphics.bitmap.config;
import android.graphics.canvas;
import android.graphics.color;
import android.graphics.paint;
import android.graphics.porterduff.mode;
import android.graphics.porterduffxfermode;
import android.graphics.rect;
import android.graphics.rectf;
import android.graphics.drawable.bitmapdrawable;
import android.graphics.drawable.drawable;
import android.os.bundle;
import android.widget.imageview;
import android.widget.linearlayout;

public class myactivity extends activity {
/** called when the activity is first created. */
@override
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.main);

// drawable drawable = getresources().getdrawable(r.drawable.bg);
// bitmapdrawable bitmapdrawable = (bitmapdrawable) drawable;
// bitmap bitmap = bitmapdrawable.getbitmap();

linearlayout layout = (linearlayout) findviewbyid(r.id.layout);
drawable drawable = getresources().getdrawable(r.drawable.bg);
bitmapdrawable bitmapdrawable = (bitmapdrawable) drawable;
bitmap bitmap = bitmapdrawable.getbitmap();

bitmapdrawable bbb = new bitmapdrawable(toroundcorner(bitmap, 30));
layout.setbackgrounddrawable(bbb);
//imageview imageview = (imageview) findviewbyid(r.id.imgshow);
//imageview.setimagebitmap(myactivity.getroundedcornerbitmap(bitmap));
//imageview.setimagebitmap(myactivity.toroundcorner(bitmap, 20));
}
public static bitmap toroundcorner(bitmap bitmap, int pixels) {

bitmap output = bitmap.createbitmap(bitmap.getwidth(), bitmap.getheight(), config.argb_8888);
canvas canvas = new canvas(output);

final int color = 0xff424242;
final paint paint = new paint();
final rect rect = new rect(0, 0, bitmap.getwidth(), bitmap.getheight());
final rectf rectf = new rectf(rect);
final float roundpx = pixels;

paint.setantialias(true);
canvas.drawargb(0, 0, 0, 0);
paint.setcolor(color);
canvas.drawroundrect(rectf, roundpx, roundpx, paint);

paint.setxfermode(new porterduffxfermode(mode.src_in));
canvas.drawbitmap(bitmap, rect, rect, paint);

return output;
}
}