本文共 3391 字，大约阅读时间需要 11 分钟。
这里介绍一个主要的方法，也是从网上找的，在此整理出来。。。以备不时之需
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; } 当我们需要圆角的时候，调用这个方法，第一个参数是传入需要转化成圆角的图片，第二个参数是圆角的度数，数值越大，圆角越大
下面兴趣个例子，我有一个LinearLayout，我想把它的背景图片设置成圆角
布局文件main.xml
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; }} 当然对ImageView设置图片也可以，不仅是background属性 上面那个类中注释的代码就是
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