056-Android圆形头像

Android圆形头像

创建一个CircleView

继承AppCompatImageView

package com.lich.lichdialect.view;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.graphics.Xfermode;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;

import androidx.appcompat.widget.AppCompatImageView;

import com.lich.lichdialect.R;
import com.lich.lichdialect.util.ColorUtil;

/**
 * Created by lichhowger on 2020/2/4.
 */
public class CircleView extends AppCompatImageView {

    private int mSize;
    private Paint mPaint;
    private Xfermode mPorterDuffXfermode;
    private Paint whitePaint;

    public CircleView(Context context) {
        this(context, null);
    }

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

    public CircleView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {

        //创建Paint
        mPaint = new Paint();
        mPaint.setDither(true);
        mPaint.setAntiAlias(true);

        //创建图像合成模式
        mPorterDuffXfermode = new PorterDuffXfermode(PorterDuff.Mode.SRC_IN);

        //创建白色的Paint
        whitePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        whitePaint.setStrokeWidth(4);
        whitePaint.setStyle(Paint.Style.STROKE);
        whitePaint.setColor(ColorUtil.getColor(R.color.white));
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        //获取width和height宽高
        int width = getMeasuredWidth();
        int height = getMeasuredHeight();

        //取宽高的最小值
        mSize = Math.min(width, height);

        //设置CircleImageView为等宽高
        setMeasuredDimension(mSize, mSize);
    }

    @Override
    protected void onDraw(Canvas canvas) {

        //获取sourceBitmap，即通过xml或者java设置进来的图片
        Drawable drawable = getDrawable();
        if (drawable == null) {
            return;
        }

        //获取Bitmap
        Bitmap sourceBitmap = ((BitmapDrawable) getDrawable()).getBitmap();
        if (sourceBitmap != null) {
            
            //对图片进行缩放，以适应控件的大小
            Bitmap bitmap = resizeBitmap(sourceBitmap, getWidth(), getHeight());
            
            //(1)利用PorterDuffXfermode实现
            //drawCircleBitmapByXfermode(canvas, bitmap);  

            //(2)利用BitmapShader实现
            drawCircleBitmapByShader(canvas, bitmap);    
        }
    }

    private void drawCircleBitmapByShader(Canvas canvas, Bitmap bitmap) {
        
        //创建BitmapShader
        BitmapShader shader = new BitmapShader(bitmap, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);
        mPaint.setShader(shader);
        
        //画出CircleView
        canvas.drawCircle(mSize / 2, mSize / 2, mSize / 2, mPaint);
        
        //画白色的圆圈
        canvas.drawCircle(mSize / 2, mSize / 2, mSize / 2 - 2, whitePaint);
    }

    /**
     * 缩放Bitmap
     * @param sourceBitmap
     * @param dstWidth
     * @param dstHeight
     * @return
     */
    private Bitmap resizeBitmap(Bitmap sourceBitmap, int dstWidth, int dstHeight) {
        int width = sourceBitmap.getWidth();
        int height = sourceBitmap.getHeight();

        float widthScale = ((float) dstWidth) / width;
        float heightScale = ((float) dstHeight) / height;

        //取最大缩放比
        float scale = Math.max(widthScale, heightScale);
        Matrix matrix = new Matrix();
        matrix.postScale(scale, scale);

        return Bitmap.createBitmap(sourceBitmap, 0, 0, width, height, matrix, true);
    }

    private void drawCircleBitmapByXfermode(Canvas canvas, Bitmap bitmap) {
        final int sc = canvas.saveLayer(0, 0, getWidth(), getHeight(), null, Canvas.ALL_SAVE_FLAG);
        //绘制dst层
        canvas.drawCircle(mSize / 2, mSize / 2, mSize / 2, mPaint);
        //设置图层混合模式为SRC_IN
        mPaint.setXfermode(mPorterDuffXfermode);
        //绘制src层
        canvas.drawBitmap(bitmap, 0, 0, mPaint);

        //画白色的圆圈
        canvas.drawCircle(mSize / 2, mSize / 2, mSize / 2 - 2, whitePaint);

        canvas.restoreToCount(sc);
    }
}