自定义圆形工具类

1.自定义圆形工具类

CircleImageViewUtil.java

关键点：可以自持缩放

package com.example.circleimageviewdemo;

import android.content.Context;
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.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

/**
 * 圆形的Imageview
 *
 * @author tf
 *
 */
public class CircleImageViewUtil extends ImageView {
	public CircleImageViewUtil(Context context) {
		this(context, null);
	}

	public CircleImageViewUtil(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
	}

	public CircleImageViewUtil(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);

	}

	@Override
	protected void onDraw(Canvas canvas) {

		Drawable drawable = getDrawable();

		if (drawable == null) {
			return;
		}

		if (getWidth() == 0 || getHeight() == 0) {
			return;
		}

		Bitmap b = ((BitmapDrawable) drawable).getBitmap();

		if (null == b) {
			return;
		}

		Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);

		int w = getWidth(), h = getHeight();

		Bitmap roundBitmap = getCroppedBitmap(bitmap, w);
		canvas.drawBitmap(roundBitmap, 0, 0, null);

	}

	public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
		Bitmap sbmp;
		if (bmp.getWidth() != radius || bmp.getHeight() != radius)
			sbmp = Bitmap.createScaledBitmap(bmp, radius, radius, false);
		else
			sbmp = bmp;
		Bitmap output = Bitmap.createBitmap(sbmp.getWidth(), sbmp.getHeight(),
				Config.ARGB_8888);
		Canvas canvas = new Canvas(output);

		final int color = 0xffa19774;
		final Paint paint = new Paint();
		final Rect rect = new Rect(0, 0, sbmp.getWidth(), sbmp.getHeight());

		paint.setAntiAlias(true);
		paint.setFilterBitmap(true);
		paint.setDither(true);
		canvas.drawARGB(0, 0, 0, 0);
		paint.setColor(Color.parseColor("#BAB399"));
		canvas.drawCircle(sbmp.getWidth() / 2 + 0.7f,
				sbmp.getHeight() / 2 + 0.7f, sbmp.getWidth() / 2 + 0.1f, paint);
		paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
		canvas.drawBitmap(sbmp, rect, rect, paint);

		return output;
	}
}

2、MainActivity.java

package com.example.circleimageviewdemo;

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.Menu;

public class MainActivity extends Activity {
	CircleImageViewUtil circle_imageview ;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_circle_image_view);
		circle_imageview = (CircleImageViewUtil) findViewById(R.id.circle_imageview);

		circle_imageview.setImageResource(R.drawable.guide3);
		//circle_imageview.setImageBitmap(bm);
		//circle_imageview.setImageDrawable(drawable)
		/*Uri uri = new Uri("");
		circle_imageview.setImageURI(uri);*/

	}

}

xml文件：

关键点： <com.example.circleimageviewdemo.CircleImageViewUtil＞

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <com.example.circleimageviewdemo.CircleImageViewUtil
        android:layout_height="80dp"
        android:layout_width="80dp"
        android:id="@+id/circle_imageview"
        >
    </com.example.circleimageviewdemo.CircleImageViewUtil>

</RelativeLayout>