分享使用BitmapShader类实现圆形、圆角，椭圆等自定义图片View
图片控件类：
public class RoundOvalImageView extends ImageView {
private Paint mPaint;
private int mWidth;
private int mHeight;
private int mRadius;//圆半径
private RectF mRect;
private int mRoundRadius;// 圆角大小
private BitmapShader mBitmapShader;//图形渲染
private Matrix mMatrix;
private int mType;// 记录是圆形还是圆角矩形
public static final int TYPE_CIRCLE = 0;// 圆形
public static final int TYPE_ROUND = 1;// 圆角矩形
public static final int TYPE_OVAL = 2;//椭圆形
public static final int DEFAUT_ROUND_RADIUS = 10;//默认圆角大小
public RoundOvalImageView(Context context) {
this(context, null);
// TODO Auto-generated constructor stub
}
public RoundOvalImageView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// TODO Auto-generated constructor stub
}
public RoundOvalImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initView();
}
private void initView() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mMatrix = new Matrix();
mRoundRadius = DEFAUT_ROUND_RADIUS;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// 如果是绘制圆形，则强制宽高大小一致
if (mType == TYPE_CIRCLE) {
mWidth = Math.min(getMeasuredWidth(), getMeasuredHeight());
mRadius = mWidth / 2;
setMeasuredDimension(mWidth, mWidth);
}
}
@Override
protected void onDraw(Canvas canvas) {
if (null == getDrawable()) {
return;
}
setBitmapShader();
if (mType == TYPE_CIRCLE) {
canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);
} else if (mType == TYPE_ROUND) {
mPaint.setColor(Color.RED);
canvas.drawRoundRect(mRect, mRoundRadius, mRoundRadius, mPaint);
} else if (mType == TYPE_OVAL) {
canvas.drawOval(mRect, mPaint);
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
// TODO Auto-generated method stub
super.onSizeChanged(w, h, oldw, oldh);
mRect = new RectF(0, 0, getWidth(), getHeight());
}
/**
* 设置BitmapShader
*/
private void setBitmapShader() {
Drawable drawable = getDrawable();
if (null == drawable) {
return;
}
Bitmap bitmap = drawableToBitmap(drawable);
// 将bitmap作为着色器来创建一个BitmapShader
mBitmapShader = new BitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP);
float scale = 1.0f;
if (mType == TYPE_CIRCLE) {
// 拿到bitmap宽或高的小值
int bSize = Math.min(bitmap.getWidth(), bitmap.getHeight());
scale = mWidth * 1.0f / bSize;
} else if (mType == TYPE_ROUND || mType == TYPE_OVAL) {
// 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 / bitmap.getWidth(), getHeight() * 1.0f / bitmap.getHeight());
}
// shader的变换矩阵，我们这里主要用于放大或者缩小
mMatrix.setScale(scale, scale);
// 设置变换矩阵
mBitmapShader.setLocalMatrix(mMatrix);
mPaint.setShader(mBitmapShader);
}
/**
* drawable转bitmap
*
* @param drawable
* @return
*/
private Bitmap drawableToBitmap(Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
return bitmapDrawable.getBitmap();
}
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(w, h, Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, w, h);
drawable.draw(canvas);
return bitmap;
}
/**
* 单位dp转单位px
*/
public int dpTodx(int dp) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dp, getResources().getDisplayMetrics());
}
public int getType() {
return mType;
}
/**
* 设置图片类型：圆形、圆角矩形、椭圆形
*
* @param mType
*/
public void setType(int mType) {
if (this.mType != mType) {
this.mType = mType;
invalidate();
}
}
public int getRoundRadius() {
return mRoundRadius;
}
/**
* 设置圆角大小
*
* @param mRoundRadius
*/
public void setRoundRadius(int mRoundRadius) {
if (this.mRoundRadius != mRoundRadius) {
this.mRoundRadius = mRoundRadius;
invalidate();
}
}
}
使用方法：
<com.baidu.ad.view.RoundOvalImageView
android:id="@+id/imgHeader"
android:layout_width="55dp"
android:layout_height="55dp"
android:layout_centerVertical="true"
android:layout_gravity="center_vertical"
android:layout_marginLeft="20dp"
android:gravity="center_vertical"
android:scaleType="centerCrop"
android:src="@drawable/logo" />-END
