android中 怎么显示一直图片为圆形图片
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比如自己拍摄了一张图片,然后显示在android,但是显示的方式是圆形的 这个是怎么实现的
我上传一个效果图,登录界面的 头像 就是我现在所描述的需求
这个头像图片就是圆形的,那这个在android是怎么实现的
public class XCRoundImageView extends ImageView
private Paint paint ; public XCRoundImageView(Context context) this(context,null);
public XCRoundImageView(Context context, AttributeSet attrs)
this(context, attrs,0);
public XCRoundImageView(Context context, AttributeSet attrs, int defStyle)
super(context, attrs, defStyle);
paint = new Paint();
/** * 绘制圆形图片
* @author caizhiming */ @Override protected void onDraw(Canvas canvas)
Drawable drawable = getDrawable(); if (null != drawable)
Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
Bitmap b = getCircleBitmap(bitmap, 14); final Rect rectSrc = new Rect(0, 0, b.getWidth(), b.getHeight()); final Rect rectDest = new Rect(0,0,getWidth(),getHeight());
paint.reset();
canvas.drawBitmap(b, rectSrc, rectDest, paint);
else super.onDraw(canvas);
/** * 获取圆形图片方法
* @param bitmap
* @param pixels
* @return Bitmap
* @author caizhiming */ private Bitmap getCircleBitmap(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 Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color); int x = bitmap.getWidth();
canvas.drawCircle(x / 2, x / 2, x / 2, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint); return output;
本回答被提问者采纳 参考技术D
将图片变为圆形图片,可以将系统ImageView替换成如下自定义 的view RoundImageView :
/**
* 圆形ImageView,可设置最多两个宽度不同且颜色不同的圆形边框。
*
* @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;
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)
TypedArray a = mContext.obtainStyledAttributes(attrs,
R.styleable.roundedimageview);
mBorderThickness = a.getDimensionPixelSize(
R.styleable.roundedimageview_border_thickness, 0);
mBorderOutsideColor = a
.getColor(R.styleable.roundedimageview_border_outside_color,
defaultColor);
mBorderInsideColor = a.getColor(
R.styleable.roundedimageview_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);
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