首先看我们定义的RoundImageView:
- 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;
- private int mBorderInsideColor = 0;
- // 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) {//这里要用到自定义属性
- TypedArray a = mContext.obtainStyledAttributes(attrs,
- R.styleable.RoundImageView);
- mBorderThickness = a.getDimensionPixelSize(
- R.styleable.RoundImageView_border_thickness, 0);
- mBorderOutsideColor = a
- .getColor(R.styleable.RoundImageView_border_outside_color,
- defaultColor);
- 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;
- }
- 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();
- }
- 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);
- bitmap = null;
- canvas.drawBitmap(roundBitmap, defaultWidth / 2 - radius, defaultHeight
- / 2 - radius, null);
- }
- /**
- * 获取裁剪后的圆形图片
- */
- 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();
- 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);
- }
- }
在res/values建一个attrs.xml文件,加入自定义属性字段
- <?xml version="1.0" encoding="utf-8"?>
- <resources>
- <declare-styleable name="RoundImageView">
- <attr name="border_thickness" format="dimension" />
- <attr name="border_outside_color" format="color" />
- <attr name="border_inside_color" format="color" />
- </declare-styleable>
- </resources>
最后就直接把这个RoundImageView看作ImageView在你需要用的地方用就可以了。
来源: http://www.phpxs.com/code/1002255/