Android RoundedBitmapDrawable：Android官方的圆角图形图象实现方案


Android RoundedBitmapDrawable：Android官方的圆角图形图象实现方案

RoundedBitmapDrawable是Android在support v4的扩展包中新增的实现圆角图形的关键类，借助RoundedBitmapDrawable的帮助，可以轻松的以Android标准方式实现圆角图形图象。

写一个简单的例子。

写一个线性布局，竖直方向放三个ImageView：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context="zhangphil.app.MainActivity">

<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="5dp" />

<ImageView
android:id="@+id/imageView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="5dp" />

<ImageView
android:id="@+id/imageView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="5dp" />

</LinearLayout>

然后通过Java代码分别放原始图，圆角图，圆形图作为对比：

package zhangphil.app;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v4.graphics.drawable.RoundedBitmapDrawable;
import android.support.v4.graphics.drawable.RoundedBitmapDrawableFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

//未做圆角处理的原始图
ImageView image1 = (ImageView) findViewById(R.id.imageView1);
image1.setImageResource(R.drawable.zhangphil);

//圆角图
RoundedBitmapDrawable roundedDrawable = RoundedBitmapDrawableFactory.create(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.zhangphil));
roundedDrawable.getPaint().setAntiAlias(true);
roundedDrawable.setCornerRadius(30);
ImageView image2 = (ImageView) findViewById(R.id.imageView2);
image2.setImageDrawable(roundedDrawable);

//圆形图
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.zhangphil);
RoundedBitmapDrawable circleDrawable = RoundedBitmapDrawableFactory.create(getResources(), BitmapFactory.decodeResource(getResources(), R.drawable.zhangphil));
circleDrawable.getPaint().setAntiAlias(true);
circleDrawable.setCornerRadius(Math.max(bitmap.getWidth(), bitmap.getHeight()));
ImageView image3 = (ImageView) findViewById(R.id.imageView3);
image3.setImageDrawable(circleDrawable);
}
}

代码运行结果：



附录文章：

1，《Android圆形头像图Circle ImageView》链接地址：/article/1810734.html

2，《Android CustomShapeImageView对图片进行各种样式裁剪：圆形、星形、心形、花瓣形等》链接地址：http://blog.csdn.net/zhangphil/article/details/50119921