本文的控件来自：http://blog.****.net/alan_biao/article/details/17379925
这个控件不同于之前介绍过的那个框架，这个仅仅能过将图片裁剪为圆形，没能弄成椭圆，也没有android:scaleType属性。但他可以提供两重边框，对于简单的使用来说，是完全够用的。
使用方式和之前一样，首先先配置attrs.xml
<!--
border_thickness 设置边框的宽度
border_inside_color 设置内边框的颜色
border_outside_color 设置外边框的颜色
内外边框如果只设置一个的话，则认为只显示一个边框。
-->
<declare-styleable name="RoundImageView">
<attr name="border_thickness" format="dimension" />
<attr name="border_inside_color" format="color" />
<attr name="border_outside_color" format="color" />
</declare-styleable>
然后建立类RoundImageView.java
package com.eva.views; import android.content.Context;
import android.content.res.TypedArray;
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.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.NinePatchDrawable;
import android.util.AttributeSet;
import android.widget.ImageView; /**
* 圆形ImageView，可设置最多两个宽度不同且颜色不同的圆形边框。
* 来源的博客：http://blog.****.net/alan_biao/article/details/17379925
* @author Alan
*/
public class RoundImageView extends ImageView {
private int mBorderThickness = 0;
private Context mContext;
private int defaultColor = 0xFFFFFFFF;
// 如果只有其中一个有值，则只画一个圆形边框
private int mBorderOutsideColor = 0;//图片的外边界
private int mBorderInsideColor = 0;//图片的内边界
// 控件默认长、宽
private int defaultWidth = 0;
private int defaultHeight = 0; public RoundImageView(Context context) {
super(context);
mContext = context;
} public RoundImageView(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
setCustomAttributes(attrs);
} public RoundImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mContext = context;
setCustomAttributes(attrs);
} private void setCustomAttributes(AttributeSet attrs) {
TypedArray a = mContext.obtainStyledAttributes(attrs,R.styleable.RoundImageView);
//边界的宽度
mBorderThickness = a.getDimensionPixelSize(
R.styleable.RoundImageView_border_thickness, 0);
//外边界的颜色
mBorderOutsideColor = a.getColor(
R.styleable.RoundImageView_border_outside_color,defaultColor);
//内边界的颜色
mBorderInsideColor = a.getColor(
R.styleable.RoundImageView_border_inside_color, defaultColor);
} @Override
protected void onDraw(Canvas canvas) {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
} if (getWidth() == 0 || getHeight() == 0) {
return;
}
this.measure(0, 0);
if (drawable.getClass() == NinePatchDrawable.class)
return;
Bitmap b = ((BitmapDrawable) drawable).getBitmap();
Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
if (defaultWidth == 0) {
defaultWidth = getWidth();
}
if (defaultHeight == 0) {
defaultHeight = getHeight();
}
// 保证重新读取图片后不会因为图片大小而改变控件宽、高的大小（针对宽、高为wrap_content布局的imageview，但会导致margin无效）
// if (defaultWidth != 0 && defaultHeight != 0) {
// LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
// defaultWidth, defaultHeight);
// setLayoutParams(params);
// } int radius = 0;
if (mBorderInsideColor != defaultColor
&& mBorderOutsideColor != defaultColor) {// 定义画两个边框，分别为外圆边框和内圆边框
radius = (defaultWidth < defaultHeight ? defaultWidth
: defaultHeight) / 2 - 2 * mBorderThickness;
// 画内圆
drawCircleBorder(canvas, radius + mBorderThickness / 2,
mBorderInsideColor);
// 画外圆
drawCircleBorder(canvas, radius + mBorderThickness
+ mBorderThickness / 2, mBorderOutsideColor);
} else if (mBorderInsideColor != defaultColor
&& mBorderOutsideColor == defaultColor) {// 定义画一个边框
radius = (defaultWidth < defaultHeight ? defaultWidth
: defaultHeight) / 2 - mBorderThickness;
drawCircleBorder(canvas, radius + mBorderThickness / 2,
mBorderInsideColor);
} else if (mBorderInsideColor == defaultColor
&& mBorderOutsideColor != defaultColor) {// 定义画一个边框
radius = (defaultWidth < defaultHeight ? defaultWidth
: defaultHeight) / 2 - mBorderThickness;
drawCircleBorder(canvas, radius + mBorderThickness / 2,
mBorderOutsideColor);
} else {// 没有边框
radius = (defaultWidth < defaultHeight ? defaultWidth
: defaultHeight) / 2;
}
Bitmap roundBitmap = getCroppedRoundBitmap(bitmap, radius);
canvas.drawBitmap(roundBitmap, defaultWidth / 2 - radius, defaultHeight
/ 2 - radius, null);
} /**
* 获取裁剪后的圆形图片
*
* @param radius
* 半径
*/
public Bitmap getCroppedRoundBitmap(Bitmap bmp, int radius) {
Bitmap scaledSrcBmp;
int diameter = radius * 2; // 为了防止宽高不相等，造成圆形图片变形，因此截取长方形中处于中间位置最大的正方形图片
int bmpWidth = bmp.getWidth();
int bmpHeight = bmp.getHeight();
int squareWidth = 0, squareHeight = 0;
int x = 0, y = 0;
Bitmap squareBitmap;
if (bmpHeight > bmpWidth) {// 高大于宽
squareWidth = squareHeight = bmpWidth;
x = 0;
y = (bmpHeight - bmpWidth) / 2;
// 截取正方形图片
squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,
squareHeight);
} else if (bmpHeight < bmpWidth) {// 宽大于高
squareWidth = squareHeight = bmpHeight;
x = (bmpWidth - bmpHeight) / 2;
y = 0;
squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,
squareHeight);
} else {
squareBitmap = bmp;
} if (squareBitmap.getWidth() != diameter
|| squareBitmap.getHeight() != diameter) {
scaledSrcBmp = Bitmap.createScaledBitmap(squareBitmap, diameter,
diameter, true); } else {
scaledSrcBmp = squareBitmap;
}
Bitmap output = Bitmap.createBitmap(scaledSrcBmp.getWidth(),
scaledSrcBmp.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output); Paint paint = new Paint();
Rect rect = new Rect(0, 0, scaledSrcBmp.getWidth(),
scaledSrcBmp.getHeight()); paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
canvas.drawARGB(0, 0, 0, 0);
canvas.drawCircle(scaledSrcBmp.getWidth() / 2,
scaledSrcBmp.getHeight() / 2, scaledSrcBmp.getWidth() / 2,
paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(scaledSrcBmp, rect, rect, paint);
// bitmap回收(recycle导致在布局文件XML看不到效果)
// bmp.recycle();
// squareBitmap.recycle();
// scaledSrcBmp.recycle();
bmp = null;
squareBitmap = null;
scaledSrcBmp = null;
return output;
} /**
* 边缘画圆
*/
private void drawCircleBorder(Canvas canvas, int radius, int color) {
Paint paint = new Paint();
/* 去锯齿 */
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
paint.setColor(color);
/* 设置paint的 style 为STROKE：空心 */
paint.setStyle(Paint.Style.STROKE);
/* 设置paint的外框宽度 */
paint.setStrokeWidth(mBorderThickness);
canvas.drawCircle(defaultWidth / 2, defaultHeight / 2, radius, paint);
} }
最后，在布局文件中设置该控件（需要添加命名空间）
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:pv="http://schemas.android.com/apk/res/com.eva.views"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#d6d6d6"
android:orientation="vertical" > <com.eva.views.RoundImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/kale"
android:layout_marginTop="16dp"
android:layout_gravity="center_horizontal" pv:border_thickness="3dp"
pv:border_inside_color="#50c0e9"/> <com.eva.views.RoundImageView
android:id="@+id/image_id"
android:layout_width="150dp"
android:layout_height="150dp"
android:src="@drawable/kale"
android:layout_marginTop="16dp"
android:layout_gravity="center_horizontal" pv:border_thickness="4dp"
pv:border_inside_color="#50c0e9"
pv:border_outside_color="#ffc641"/> <com.eva.views.RoundImageView
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@drawable/kale"
android:layout_marginTop="16dp"
android:layout_gravity="center_horizontal" pv:border_thickness="3dp"
pv:border_inside_color="#d6d6d6"
pv:border_outside_color="#ffc641"/> </LinearLayout>
我们在代码中可以和用ImageView一样来设置图片
RoundImageView imageView = (RoundImageView)findViewById(R.id.image_id);
imageView.setImageDrawable(getResources().getDrawable(R.drawable.saber));
imageView.setImageResource(R.drawable.saber);