android圆形图片显示ImageView超简单控件

关于android显示圆形图片的控件

public class RoundImageView extends ImageView {

/** 图片的类型，圆形or圆角 */
private int type;
private static final int TYPE_CIRCLE = 0;
private static final int TYPE_ROUND = 1;

/** 圆角大小的默认值 */
private static final int BODER_RADIUS_DEFAULT = 10;
/** * 圆角的大小 */
private int mBorderRadius;

/** * 绘图的Paint */
private Paint mBitmapPaint;
/** * 圆角的半径 */
private int 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;
private RectF mRoundRect;

public RoundImageView(Context context, AttributeSet attrs) {
super(context, attrs);
mMatrix = new Matrix();
mBitmapPaint = new Paint();
mBitmapPaint.setAntiAlias(true);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.RoundImageView);
mBorderRadius = a.getDimensionPixelSize(
R.styleable.RoundImageView_borderRadius, (int) TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
BODER_RADIUS_DEFAULT, getResources()
.getDisplayMetrics()));// 默认为10dp
type = a.getInt(R.styleable.RoundImageView_type, TYPE_CIRCLE);// 默认为Circle
a.recycle();
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (type == TYPE_CIRCLE) {
mWidth = Math.min(getMeasuredWidth(), getMeasuredHeight());
mRadius = mWidth / 2;
setMeasuredDimension(mWidth, mWidth);
}

}

private void setUpShader() {
Drawable drawable = getDrawable();
if (drawable == null)
return;
Bitmap bmp = drawableToBitamp(drawable);
// 将bmp作为着色器，就是在指定区域内绘制bmp
mBitmapShader = new BitmapShader(bmp, TileMode.CLAMP, TileMode.CLAMP);
float scale = 1.0f;
if (type == TYPE_CIRCLE) {
int bSize = Math.min(bmp.getWidth(), bmp.getHeight());
scale = mWidth * 1.0f / bSize;

} else if (type == TYPE_ROUND) {
scale = Math.max(getWidth() * 1.0f / bmp.getWidth(), getHeight()
* 1.0f / bmp.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);
// 设置shader
mBitmapPaint.setShader(mBitmapShader);
}

private Bitmap drawableToBitamp(Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bd = (BitmapDrawable) drawable;
return bd.getBitmap();
}
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, w, h);
drawable.draw(canvas);
return bitmap;
}

@Override
protected void onDraw(Canvas canvas) {
if (getDrawable() == null)
return;
setUpShader();
if (type == TYPE_ROUND) {
canvas.drawRoundRect(mRoundRect, mBorderRadius, mBorderRadius,
mBitmapPaint);
} else {
canvas.drawCircle(mRadius, mRadius, mRadius, mBitmapPaint);
}
}

@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)
mRoundRect = new RectF(0, 0, getWidth(), getHeight());
}
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<...RoundImageView
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>