實現Android圖片圓角

這裡介紹一個主要的方法，也是從網上找的，在此整理出來。。。以備不時之需
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; 
    }
當我們需要圓角的時候，調用這個方法，第一個參數是傳入需要轉化成圓角的圖片，第二個參數是圓角的度數，數值越大，圓角越大
下面興趣個例子，我有一個LinearLayout，我想把它的背景圖片設定成圓角
布局檔案main.xml
<?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; 
    }
}
 

當然對ImageView設定圖片也可以，不僅是background屬性
上面那個類中注釋的代碼就是

摘自：and