Android 實現圖片的圓角

/** * 擷取圓角位元影像的方法 * @param bitmap 需要轉化成圓角的位元影像 * @param pixels 圓角的度數，數值越大，圓角越大 * @return 處理後的圓角位元影像 */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;}

下面就測試一下這個方法，將一個Activity的背景圖設定為圓角，即將Activity的LinerLayout的背景設定為圓角：

設定檔 main.xml：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/layout"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" ></LinearLayout>

import android.app.Activity;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.Canvas;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.LinearLayout;/** * 將Activity的背景圖設定為圓角圖 */public class AndroidTestActivity extends Activity {/** Called when the activity is first created. */@Overridepublic 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.yexuan);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));}/** * 擷取圓角位元影像的方法 * @param bitmap 需要轉化成圓角的位元影像 * @param pixels 圓角的度數，數值越大，圓角越大 * @return 處理後的圓角位元影像 */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;}}

轉載於：http://blog.csdn.net/akon_vm/article/details/7418210