自定义圆角ImageVIew

今天继续写写博客，坚持下去懒癌是有救的。这个控件可以给图片带上圆角矩形或者圆形效果，并可以设置外带的边框。废话少说，先看看事例图：

上面两个就是正圆和圆角矩形的效果啦。它会自动缩放图片使之中心对齐铺满。

下面是写在属性文件里的自定义属性，边框颜色，边框大小，图片，是否是圆形，圆角值：

下面是控件的代码：

package com.example.huangyi.test.widge;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
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.Drawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import com.example.huangyi.test.R;

/**
 * Created by huangyi on 17-5-23.
 */

public class CircleImageView extends View {
    private static final int MIN_WIDTH = 30;
    private static final int MIN_HEIGHT = 30;

    private boolean isCircle;
    private float radius;
    private int centerX;
    private int centerY;

    private float strokeWidth;
    private int strokeColor;

    private Paint mStrockPaint;
    private Paint mBitmapPaint;
    private BitmapShader bitmapShader;
    private Bitmap bitmap;

    public CircleImageView(Context context) {
        super(context);
        init(context,null);
    }

    public CircleImageView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init(context,attrs);
    }

    public CircleImageView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context,attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int wSize = MeasureSpec.getSize(widthMeasureSpec);
        int hSize = MeasureSpec.getSize(heightMeasureSpec);
        int wMode = MeasureSpec.getMode(widthMeasureSpec);
        int hMode = MeasureSpec.getMode(heightMeasureSpec);

        int bitmapW = bitmap.getWidth();
        int bitmapH = bitmap.getHeight();

        if(wMode == MeasureSpec.AT_MOST){
            wSize = Math.min(wSize,Math.max(bitmapW,MIN_WIDTH));
        }
        if(hMode == MeasureSpec.AT_MOST){
            hSize = Math.min(hSize,Math.max(bitmapH,MIN_HEIGHT));
        }

        if(isCircle){
            centerX = wSize/2;
            centerY = hSize/2;
            radius = wSize > hSize?hSize/2:wSize/2;
        }

        setMeasuredDimension(MeasureSpec.makeMeasureSpec(wSize,wMode),
                MeasureSpec.makeMeasureSpec(hSize,hMode));
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        setUpBitmapShader();
        if(isCircle){
            canvas.drawCircle(centerX,centerY,radius-strokeWidth,mBitmapPaint);
            canvas.drawCircle(centerX,centerY,radius-strokeWidth,mStrockPaint);
        }else{
            RectF rectF = new RectF(0+strokeWidth,0+strokeWidth,getWidth()-strokeWidth,getHeight()-strokeWidth);
            canvas.drawRoundRect(rectF,radius,radius,mBitmapPaint);
            canvas.drawRoundRect(rectF,radius,radius,mStrockPaint);
        }
    }

    private void init(Context context,AttributeSet attrs){

        TypedArray ta = context.getResources().obtainAttributes(attrs, R.styleable.CircleImageView);
        strokeWidth = ta.getDimension(R.styleable.CircleImageView_strokeWidth,0);
        if(strokeWidth > 0){
            strokeColor = ta.getColor(R.styleable.CircleImageView_strokeColor,0x66000000);
        }
        Drawable drawable = ta.getDrawable(R.styleable.CircleImageView_image);
        bitmap = drawable2Bitmap(drawable);

        isCircle = ta.getBoolean(R.styleable.CircleImageView_isCircle,false);
        radius = ta.getDimension(R.styleable.CircleImageView_radius,0);
        ta.recycle();

        mStrockPaint = new Paint();
        mStrockPaint.setAntiAlias(true);
        mStrockPaint.setStyle(Paint.Style.STROKE);
        mStrockPaint.setStrokeWidth(strokeWidth);
        mStrockPaint.setColor(strokeColor);

        mBitmapPaint = new Paint();
        mBitmapPaint.setAntiAlias(true);
    }

    private Bitmap drawable2Bitmap(Drawable drawable){
        if(drawable != null && drawable instanceof BitmapDrawable){
            return ((BitmapDrawable) drawable).getBitmap();
        }

        Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
                drawable.getIntrinsicHeight(),Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0,0,drawable.getIntrinsicWidth(),
                drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        return bitmap;
    }

    /**
     * 设置图片缩放比例
     */
    private void setUpBitmapShader(){
        float scale = 1.0f;
        Matrix m = new Matrix();
        m.postTranslate(getWidth()/2-bitmap.getWidth()/2,getHeight()/2-bitmap.getHeight()/2);
        if(isCircle){
            int size = Math.min(bitmap.getWidth(),bitmap.getHeight());
            scale = (2.0f*radius)/size;
        }else{
            scale = Math.max(1.0f*getWidth()/bitmap.getWidth(),
                    1.0f*getHeight()/bitmap.getHeight());
        }
        m.postScale(scale,scale,getWidth()/2,getHeight()/2);
        bitmapShader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
        bitmapShader.setLocalMatrix(m);
        mBitmapPaint.setShader(bitmapShader);
    }

    public void setImage(Bitmap b){
        if(b == null){
            return;
        }
        bitmap = b;
        invalidate();
    }

    public void setImage(Drawable d){
        if(d == null){
            return;
        }

        bitmap = drawable2Bitmap(d);
        invalidate();
    }
}

测试的布局文件：

解释先不写了，回头再编辑加入。有需求的多看两眼也能明白定义过程。