Android学习（二十）设置自定义圆形图片

在Android的开发过程中往往需要用到显示用户头像的功能，此时就需要进行圆形显示更加的美观，在使用layout布局的使用可以折用drawable进行这是圆角，但是是通过background进行引入的，此时对与src引入的图片怎么无效了，此时就需要用到自定义的设置圆形的方式了。

由于方法也是直接从网上上找到了，所以直接张贴代码了

一、在values下面新建sttr.xml文件，写入以下信息：

<?xml version="1.0" encoding="utf-8"?><resources>    <attr name="borderRadius" format="dimension" />    <attr name="type">        <enum name="circle" value="0" />        <enum name="round" value="1" />    </attr>    <declare-styleable name="RoundImageView">        <attr name="borderRadius" />        <attr name="type" />    </declare-styleable></resources>

二、新建一个Java类叫做RoundImageView

package com.example.zhengbinchen.util;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.os.Bundle;import android.os.Parcelable;import android.util.AttributeSet;import android.util.Log;import android.util.TypedValue;import android.widget.ImageView;import com.example.zhengbinchen.readingtreasure.R;/** * 圆形ImageView，可设置最多两个宽度不同且颜色不同的圆形边框。 * * @author Alan */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)    {        Log.e("TAG", "onMeasure");        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        /**         * 如果类型是圆形，则强制改变view的宽高一致，以小值为准         */        if (type == TYPE_CIRCLE)        {            mWidth = Math.min(getMeasuredWidth(), getMeasuredHeight());            mRadius = mWidth / 2;            setMeasuredDimension(mWidth, mWidth);        }    }    /**     * 初始化BitmapShader     */    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, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);        float scale = 1.0f;        if (type == TYPE_CIRCLE)        {            // 拿到bitmap宽或高的小值            int bSize = Math.min(bmp.getWidth(), bmp.getHeight());            scale = mWidth * 1.0f / bSize;        } else if (type == TYPE_ROUND)        {            // 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 / 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);    }    /**     * drawable转bitmap     *     * @param drawable     * @return     */    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);            // drawSomeThing(canvas);        }    }    @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());    }    private static final String STATE_INSTANCE = "state_instance";    private static final String STATE_TYPE = "state_type";    private static final String STATE_BORDER_RADIUS = "state_border_radius";    @Override    protected Parcelable onSaveInstanceState()    {        Bundle bundle = new Bundle();        bundle.putParcelable(STATE_INSTANCE, super.onSaveInstanceState());        bundle.putInt(STATE_TYPE, type);        bundle.putInt(STATE_BORDER_RADIUS, mBorderRadius);        return bundle;    }    @Override    protected void onRestoreInstanceState(Parcelable state)    {        if (state instanceof Bundle)        {            Bundle bundle = (Bundle) state;            super.onRestoreInstanceState(((Bundle) state)                    .getParcelable(STATE_INSTANCE));            this.type = bundle.getInt(STATE_TYPE);            this.mBorderRadius = bundle.getInt(STATE_BORDER_RADIUS);        } else        {            super.onRestoreInstanceState(state);        }    }    public void setBorderRadius(int borderRadius)    {        int pxVal = dp2px(borderRadius);        if (this.mBorderRadius != pxVal)        {            this.mBorderRadius = pxVal;            invalidate();        }    }    public void setType(int type)    {        if (this.type != type)        {            this.type = type;            if (this.type != TYPE_ROUND && this.type != TYPE_CIRCLE)            {                this.type = TYPE_CIRCLE;            }            requestLayout();        }    }    public int dp2px(int dpVal)    {        return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,                dpVal, getResources().getDisplayMetrics());    }}

三、然后在布局中进行设置

<com.example.zhengbinchen.util.RoundImageView                android:layout_width="60dp"                android:layout_height="60dp"                android:src="@drawable/person01"                app:borderRadius="60dp"                app:type="round"                />

四、效果展示