自定义圆形图片

package com.example.day10_photo;






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.RectF;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
/**
 * 圆形图片
 * @author Wang.J.L
 *
 */
public class CircleImageView extends ImageView {


    private static final ScaleType SCALE_TYPE = ScaleType.CENTER_CROP;


    private static final Bitmap.Config BITMAP_CONFIG = Bitmap.Config.ARGB_8888;
    private static final int COLORDRAWABLE_DIMENSION = 1;


    private static final int DEFAULT_BORDER_WIDTH = 0;
    /**
     * 图片外圈的颜色
     */
    private static final int DEFAULT_BORDER_COLOR = Color.WHITE;


    private final RectF mDrawableRect = new RectF();
    private final RectF mBorderRect = new RectF();


    private final Matrix mShaderMatrix = new Matrix();
    private final Paint mBitmapPaint = new Paint();
    private final Paint mBorderPaint = new Paint();


    private int mBorderColor = DEFAULT_BORDER_COLOR;
    private int mBorderWidth = DEFAULT_BORDER_WIDTH;


    private Bitmap mBitmap;
    private BitmapShader mBitmapShader;
    private int mBitmapWidth;
    private int mBitmapHeight;


    private float mDrawableRadius;
    private float mBorderRadius;


    private boolean mReady;
    private boolean mSetupPending;


    public CircleImageView(Context context) {
        super(context);
    }


    public CircleImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }


    public CircleImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        super.setScaleType(SCALE_TYPE);


        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleImageView, defStyle, 0);


        mBorderWidth = a.getDimensionPixelSize(R.styleable.CircleImageView_border_width, DEFAULT_BORDER_WIDTH);
        mBorderColor = a.getColor(R.styleable.CircleImageView_border_color, DEFAULT_BORDER_COLOR);


        a.recycle();


        mReady = true; 


        if (mSetupPending) {
            setup();
            mSetupPending = false;
        }
    }


    @Override
    public ScaleType getScaleType() {
        return SCALE_TYPE;
    }


    @Override
    public void setScaleType(ScaleType scaleType) {
        if (scaleType != SCALE_TYPE) {
            throw new IllegalArgumentException(String.format("ScaleType %s not supported.", scaleType));
        }
    }


    @Override
    protected void onDraw(Canvas canvas) {
        if (getDrawable() == null) {
            return;
        }


        canvas.drawCircle(getWidth() / 2, getHeight() / 2, mDrawableRadius, mBitmapPaint);
        canvas.drawCircle(getWidth() / 2, getHeight() / 2, mBorderRadius, mBorderPaint);
    }


    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        setup();
    }


    public int getBorderColor() {
        return mBorderColor;
    }


    public void setBorderColor(int borderColor) {
        if (borderColor == mBorderColor) {
            return;
        }


        mBorderColor = borderColor;
        mBorderPaint.setColor(mBorderColor);
        invalidate();
    }


    public int getBorderWidth() {
        return mBorderWidth;
    }


    public void setBorderWidth(int borderWidth) {
        if (borderWidth == mBorderWidth) {
            return;
        }


        mBorderWidth = borderWidth;
        setup();
    }


    @Override
    public void setImageBitmap(Bitmap bm) {
        super.setImageBitmap(bm);
        mBitmap = bm;
        setup();
    }


    @Override
    public void setImageDrawable(Drawable drawable) {
        super.setImageDrawable(drawable);
        mBitmap = getBitmapFromDrawable(drawable);
        setup();
    }


    @Override
    public void setImageResource(int resId) {
        super.setImageResource(resId);
        mBitmap = getBitmapFromDrawable(getDrawable());
        setup();
    }


    private Bitmap getBitmapFromDrawable(Drawable drawable) {
        if (drawable == null) {
            return null;
        }


        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable) drawable).getBitmap();
        }


        try {
            Bitmap bitmap;


            if (drawable instanceof ColorDrawable) {
                bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION, COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);

            } else {

  bitmap = Bitmap.createBitmap(COLORDRAWABLE_DIMENSION, COLORDRAWABLE_DIMENSION, BITMAP_CONFIG);

           //     bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), BITMAP_CONFIG);
            }


            Canvas canvas = new Canvas(bitmap);
            drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
            drawable.draw(canvas);
            return bitmap;
        } catch (OutOfMemoryError e) {
            return null;
        }
    }


    private void setup() {
        if (!mReady) {
            mSetupPending = true;
            return;
        }


        if (mBitmap == null) {
            return;
        }


        mBitmapShader = new BitmapShader(mBitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);


        mBitmapPaint.setAntiAlias(true);
        mBitmapPaint.setShader(mBitmapShader);


        mBorderPaint.setStyle(Paint.Style.STROKE);
        mBorderPaint.setAntiAlias(true);
        mBorderPaint.setColor(mBorderColor);
        mBorderPaint.setStrokeWidth(mBorderWidth);


        mBitmapHeight = mBitmap.getHeight();
        mBitmapWidth = mBitmap.getWidth();


        mBorderRect.set(0, 0, getWidth(), getHeight());
        mBorderRadius = Math.min((mBorderRect.height() - mBorderWidth) / 2, (mBorderRect.width() - mBorderWidth) / 2);


        mDrawableRect.set(mBorderWidth, mBorderWidth, mBorderRect.width() - mBorderWidth, mBorderRect.height() - mBorderWidth);
        mDrawableRadius = Math.min(mDrawableRect.height() / 2, mDrawableRect.width() / 2);


        updateShaderMatrix();
        invalidate();
    }


    private void updateShaderMatrix() {
        float scale;
        float dx = 0;
        float dy = 0;


        mShaderMatrix.set(null);


        if (mBitmapWidth * mDrawableRect.height() > mDrawableRect.width() * mBitmapHeight) {
            scale = mDrawableRect.height() / (float) mBitmapHeight;
            dx = (mDrawableRect.width() - mBitmapWidth * scale) * 0.5f;
        } else {
            scale = mDrawableRect.width() / (float) mBitmapWidth;
            dy = (mDrawableRect.height() - mBitmapHeight * scale) * 0.5f;
        }


        mShaderMatrix.setScale(scale, scale);
        mShaderMatrix.postTranslate((int) (dx + 0.5f) + mBorderWidth, (int) (dy + 0.5f) + mBorderWidth);


        mBitmapShader.setLocalMatrix(mShaderMatrix);
    }

}

<?xml version="1.0" encoding="utf-8"?>
<resources>

attrs.xml
    <declare-styleable name="RotateTextView">
        <attr name="degree" format="dimension" />
    </declare-styleable>
    <declare-styleable name="CircleImageView">
        <attr name="border_width" format="dimension" />
        <attr name="border_color" format="color" />
    </declare-styleable>
    <declare-styleable name="CropImageView">
        <attr name="guidelines">
            <enum name="on" value="2" />
            <enum name="onTouch" value="1" />
            <enum name="off" value="0" />
        </attr>
        <attr name="fixAspectRatio" format="boolean" />
        <attr name="aspectRatioX" format="integer" />
        <attr name="aspectRatioY" format="integer" />
        <attr name="imageResource" format="reference" />
    </declare-styleable>
    


</resources>