只需要建两个文件(attrs.xml文件和RoundImageView类),就可以用了,步骤简单.
1.先在res/values目录下新建attrs.xml文件,文件如下:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="RoundImageView">
<!-- 描边宽度-->
<attr name="border_width" format="dimension"/>
<!-- 描边颜色-->
<attr name="border_color" format="color"/>
<!--圆角大小-->
<attr name="corner_radius" format="dimension"/>
<!--左上圆角大小-->
<attr name="leftTop_corner_radius" format="dimension"/>
<!--右上圆角大小-->
<attr name="rightTop_corner_radius" format="dimension"/>
<!--左下圆角大小-->
<attr name="leftBottom_corner_radius" format="dimension"/>
<!--右下圆角大小-->
<attr name="rightBottom_corner_radius" format="dimension"/>
<!--图片类型：圆角或者圆形-->
<attr name="type" format="enum">
<enum name="oval" value="2"/>
<enum name="round" value="1"/>
<enum name="circle" value="0"/>
</attr>
</declare-styleable>
</resources>
2.新建RoundImageView自定义组件,代码如下(ImageView 可能爆红,暂时不用管它):
package com.win.a01;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.ImageView;
/**
* 圆形、圆角图片
*/
public class RoundImageView extends ImageView {
/**
* 图片的类型，圆形or圆角
*/
private int type;
public static final int TYPE_CIRCLE = 0;
public static final int TYPE_ROUND = 1;
public static final int TYPE_OVAL = 2;
/**
* 描边的颜色、宽度
*/
private int mBorderColor;
private float mBorderWidth;
/**
* 圆角的大小
*/
private float mCornerRadius;
//左上角圆角大小
private float mLeftTopCornerRadius;
//右上角圆角大小
private float mRightTopCornerRadius;
//左下角圆角大小
private float mLeftBottomCornerRadius;
//右下角圆角大小
private float mRightBottomCornerRadius;
/**
* 绘图的Paint
*/
private Paint mBitmapPaint;
private Paint mBorderPaint;
/**
* 圆角的半径
*/
private float mRadius;
/**
* 3x3 矩阵，主要用于缩小放大
*/
private Matrix mMatrix;
/**
* 渲染图像，使用图像为绘制图形着色
*/
private BitmapShader mBitmapShader;
/**
* view的宽度
*/
private int mWidth;
/**
* 圆角图片区域
*/
private RectF mRoundRect;
private Path mRoundPath;
private boolean useUnitDip = true;
public RoundImageView(Context context) {
this(context, null);
}
public RoundImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public RoundImageView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundImageView, defStyleAttr, 0);
type = a.getInt(R.styleable.RoundImageView_type, TYPE_OVAL);
mBorderColor = a.getColor(R.styleable.RoundImageView_border_color, Color.WHITE);
mBorderWidth = a.getDimension(R.styleable.RoundImageView_border_width, 0);
mCornerRadius = a.getDimension(R.styleable.RoundImageView_corner_radius, dp2px(10));
mLeftTopCornerRadius = a.getDimension(R.styleable.RoundImageView_leftTop_corner_radius, 0);
mLeftBottomCornerRadius = a.getDimension(R.styleable.RoundImageView_leftBottom_corner_radius, 0);
mRightTopCornerRadius = a.getDimension(R.styleable.RoundImageView_rightTop_corner_radius, 0);
mRightBottomCornerRadius = a.getDimension(R.styleable.RoundImageView_rightBottom_corner_radius, 0);
a.recycle();
init();
}
private void init() {
mRoundPath = new Path();
mRoundRect = new RectF();
mMatrix = new Matrix();
mBitmapPaint = new Paint();
mBitmapPaint.setAntiAlias(true);
mBorderPaint = new Paint();
mBorderPaint.setAntiAlias(true);
mBorderPaint.setStyle(Paint.Style.STROKE);
updateStrokePaint();
}
private void updateStrokePaint() {
mBorderPaint.setColor(mBorderColor);
mBorderPaint.setStrokeWidth(mBorderWidth);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
/**
* 如果类型是圆形，则强制改变view的宽高一致，以小值为准
*/
if (type == TYPE_CIRCLE) {
mWidth = Math.min(MeasureSpec.getSize(widthMeasureSpec),
MeasureSpec.getSize(heightMeasureSpec));
mRadius = mWidth / 2 - mBorderWidth / 2;
setMeasuredDimension(mWidth, mWidth);
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// 圆角图片的范围
if (type == TYPE_ROUND || type == TYPE_OVAL) {
mRoundRect.set(mBorderWidth / 2, mBorderWidth / 2, w - mBorderWidth / 2, h - mBorderWidth / 2);
}
}
@Override
protected void onDraw(Canvas canvas) {
if (getDrawable() == null) {
return;
}
setupShader();
if (type == TYPE_ROUND) {
setRoundPath();
canvas.drawPath(mRoundPath, mBitmapPaint);
//绘制描边
if (mBorderWidth > 0) {
canvas.drawPath(mRoundPath, mBorderPaint);
}
} else if (type == TYPE_CIRCLE) {
canvas.drawCircle(mRadius + mBorderWidth / 2, mRadius + mBorderWidth / 2, mRadius, mBitmapPaint);
//绘制描边
if (mBorderWidth > 0) {
canvas.drawCircle(mRadius + mBorderWidth / 2, mRadius + mBorderWidth / 2, mRadius, mBorderPaint);
}
} else {
canvas.drawOval(mRoundRect, mBitmapPaint);
//绘制描边
if (mBorderWidth > 0) {
canvas.drawOval(mRoundRect, mBorderPaint);
}
}
}
private void setRoundPath() {
mRoundPath.reset();
/**
* 如果四个圆角大小都是默认值0，
* 则将四个圆角大小设置为mCornerRadius的值
*/
if (mLeftTopCornerRadius == 0 &&
mLeftBottomCornerRadius == 0 &&
mRightTopCornerRadius == 0 &&
mRightBottomCornerRadius == 0) {
mRoundPath.addRoundRect(mRoundRect,
new float[]{
mCornerRadius, mCornerRadius,
mCornerRadius, mCornerRadius,
mCornerRadius, mCornerRadius,
mCornerRadius, mCornerRadius},
Path.Direction.CW);
} else {
mRoundPath.addRoundRect(mRoundRect,
new float[]{
mLeftTopCornerRadius, mLeftTopCornerRadius,
mRightTopCornerRadius, mRightTopCornerRadius,
mRightBottomCornerRadius, mRightBottomCornerRadius,
mLeftBottomCornerRadius, mLeftBottomCornerRadius},
Path.Direction.CW);
}
}
/**
* 初始化BitmapShader
*/
private void setupShader() {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
Bitmap bmp = drawableToBitmap(drawable);
if (bmp == null) {
return;
}
// 将bmp作为着色器，就是在指定区域内绘制bmp
mBitmapShader = new BitmapShader(bmp, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
mMatrix.setTranslate(0, 0);
float scale = 1.0f;
if (type == TYPE_CIRCLE) {
if (bmp.getWidth() != getWidth() || bmp.getHeight() != getHeight()) {
// 拿到bitmap宽或高的小值
int bSize = Math.min(bmp.getWidth(), bmp.getHeight());
scale = mWidth * 1.0f / bSize;
//使缩放后的图片居中
float dx = (bmp.getWidth() * scale - mWidth) / 2;
float dy = (bmp.getHeight() * scale - mWidth) / 2;
mMatrix.setTranslate(-dx, -dy);
}
} else if (type == TYPE_ROUND || type == TYPE_OVAL) {
if (bmp.getWidth() != getWidth() || bmp.getHeight() != getHeight()) {
// 如果图片的宽或者高与view的宽高不匹配，计算出需要缩放的比例；缩放后的图片的宽高，一定要大于我们view的宽高；所以我们这里取大值；
scale = Math.max(getWidth() * 1.0f / bmp.getWidth(),
getHeight() * 1.0f / bmp.getHeight());
//使缩放后的图片居中
float dx = (scale * bmp.getWidth() - getWidth()) / 2;
float dy = (scale * bmp.getHeight() - getHeight()) / 2;
mMatrix.setTranslate(-dx, -dy);
}
}
// shader的变换矩阵，我们这里主要用于放大或者缩小
mMatrix.preScale(scale, scale);
// 设置变换矩阵
mBitmapShader.setLocalMatrix(mMatrix);
// 设置shader
mBitmapPaint.setShader(mBitmapShader);
}
/**
* drawable转bitmap
*/
private Bitmap drawableToBitmap(Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bd = (BitmapDrawable) drawable;
return bd.getBitmap();
}
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
Bitmap bitmap = null;
try {
bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, w, h);
drawable.draw(canvas);
} catch (OutOfMemoryError ignore) {
}
return bitmap;
}
/**
* 设置图片类型:
* imageType=0 圆形图片
* imageType=1 圆角图片
* 默认为圆形图片
*/
public RoundImageView setType(int imageType) {
if (this.type != imageType) {
this.type = imageType;
if (this.type != TYPE_ROUND && this.type != TYPE_CIRCLE && this.type != TYPE_OVAL) {
this.type = TYPE_OVAL;
}
requestLayout();
}
return this;
}
/**
* 设置圆角图片的圆角大小
*/
public RoundImageView setCornerRadius(int cornerRadius) {
cornerRadius = dp2px(cornerRadius);
if (mCornerRadius != cornerRadius) {
mCornerRadius = cornerRadius;
invalidate();
}
return this;
}
/**
* 设置圆角图片的左上圆角大小
*/
public RoundImageView setLeftTopCornerRadius(int cornerRadius) {
cornerRadius = dp2px(cornerRadius);
if (mLeftTopCornerRadius != cornerRadius) {
mLeftTopCornerRadius = cornerRadius;
invalidate();
}
return this;
}
/**
* 设置圆角图片的右上圆角大小
*/
public RoundImageView setRightTopCornerRadius(int cornerRadius) {
cornerRadius = dp2px(cornerRadius);
if (mRightTopCornerRadius != cornerRadius) {
mRightTopCornerRadius = cornerRadius;
invalidate();
}
return this;
}
/**
* 设置圆角图片的左下圆角大小
*/
public RoundImageView setLeftBottomCornerRadius(int cornerRadius) {
cornerRadius = dp2px(cornerRadius);
if (mLeftBottomCornerRadius != cornerRadius) {
mLeftBottomCornerRadius = cornerRadius;
invalidate();
}
return this;
}
/**
* 设置圆角图片的右下圆角大小
*/
public RoundImageView setRightBottomCornerRadius(int cornerRadius) {
cornerRadius = dp2px(cornerRadius);
if (mRightBottomCornerRadius != cornerRadius) {
mRightBottomCornerRadius = cornerRadius;
invalidate();
}
return this;
}
/**
* 设置描边宽度
*/
public RoundImageView setBorderWidth(int borderWidth) {
borderWidth = dp2px(borderWidth);
if (mBorderWidth != borderWidth) {
mBorderWidth = borderWidth;
updateStrokePaint();
invalidate();
}
return this;
}
/**
* 设置描边颜色
*/
public RoundImageView setBorderColor(int borderColor) {
if (mBorderColor != borderColor) {
mBorderColor = borderColor;
updateStrokePaint();
invalidate();
}
return this;
}
private int dp2px(int dpVal) {
if (!useUnitDip) {
return dpVal;
}
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dpVal, getResources().getDisplayMetrics());
}
public boolean isUseUnitDip() {
return useUnitDip;
}
public void setUseUnitDip(boolean useUnitDip) {
this.useUnitDip = useUnitDip;
}
}
现在就可以应用了:在布局文件中自定义各个属性就好了.
<com.win.a01.RoundImageView
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@mipmap/ic_launcher"
app:border_color="#CC0000"
app:border_width="10dp"
app:leftBottom_corner_radius="0dp"
app:leftTop_corner_radius="10dp"
app:rightBottom_corner_radius="20dp"
app:rightTop_corner_radius="30dp"
app:type="round" />
源码:GitHub上源码