自定義圓形圖片控件

RoundImageView.java
package com.ine.view.tool;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.NinePatchDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;

import com.ine.youwen.R;

/**
 * 圓形ImageView，可設置最多兩個寬度不同且顏色不同的圓形邊框。 設置顏色在xml佈局文件中由自定義屬性配置參數指定
 */
public class RoundImageView extends ImageView
{
    private int mBorderThickness = 0;
    private Context mContext;
    private int defaultColor = 0xFFFFFFFF;
    // 如果只有其中一個有值，則只畫一個圓形邊框
    private int mBorderOutsideColor = 0;
    private int mBorderInsideColor = 0;
    // 控件默認長、寬
    private int defaultWidth = 0;
    private int defaultHeight = 0;

    public RoundImageView(Context context)
    {
        super(context);
        mContext = context;
    }

    public RoundImageView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        mContext = context;
        setCustomAttributes(attrs);
    }

    public RoundImageView(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        mContext = context;
        setCustomAttributes(attrs);
    }

    @SuppressLint("Recycle")
    private void setCustomAttributes(AttributeSet attrs)
    {
        TypedArray a =
                mContext.obtainStyledAttributes(attrs,
                        R.styleable.roundedimageview);
        mBorderThickness =
                a.getDimensionPixelSize(
                        R.styleable.roundedimageview_border_thickness, 0);
        mBorderOutsideColor =
                a.getColor(R.styleable.roundedimageview_border_outside_color,
                        defaultColor);
        mBorderInsideColor =
                a.getColor(R.styleable.roundedimageview_border_inside_color,
                        defaultColor);
    }

    @Override
    protected void onDraw(Canvas canvas)
    {
        Drawable drawable = getDrawable();
        if (drawable == null)
        {
            return;
        }
        if (getWidth() == 0 || getHeight() == 0)
        {
            return;
        }
        this.measure(0, 0);
        if (drawable.getClass() == NinePatchDrawable.class)
            return;
        Bitmap b = ((BitmapDrawable) drawable).getBitmap();
        Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
        if (defaultWidth == 0)
        {
            defaultWidth = getWidth();
        }
        if (defaultHeight == 0)
        {
            defaultHeight = getHeight();
        }
        int radius = 0;
        if (mBorderInsideColor != defaultColor
                && mBorderOutsideColor != defaultColor)
        {// 定義畫兩個邊框，分別爲外圓邊框和內圓邊框
            radius =
                    (defaultWidth < defaultHeight ? defaultWidth
                            : defaultHeight) / 2 - 2 * mBorderThickness;
            // 畫內圓
            drawCircleBorder(canvas, radius + mBorderThickness / 2,
                    mBorderInsideColor);
            // 畫外圓
            drawCircleBorder(canvas, radius + mBorderThickness
                    + mBorderThickness / 2, mBorderOutsideColor);
        } else if (mBorderInsideColor != defaultColor
                && mBorderOutsideColor == defaultColor)
        {// 定義畫一個邊框
            radius =
                    (defaultWidth < defaultHeight ? defaultWidth
                            : defaultHeight) / 2 - mBorderThickness;
            drawCircleBorder(canvas, radius + mBorderThickness / 2,
                    mBorderInsideColor);
        } else if (mBorderInsideColor == defaultColor
                && mBorderOutsideColor != defaultColor)
        {// 定義畫一個邊框
            radius =
                    (defaultWidth < defaultHeight ? defaultWidth
                            : defaultHeight) / 2 - mBorderThickness;
            drawCircleBorder(canvas, radius + mBorderThickness / 2,
                    mBorderOutsideColor);
        } else
        {// 沒有邊框
            radius =
                    (defaultWidth < defaultHeight ? defaultWidth
                            : defaultHeight) / 2;
        }
        Bitmap roundBitmap = getCroppedRoundBitmap(bitmap, radius);
        canvas.drawBitmap(roundBitmap, defaultWidth / 2 - radius, defaultHeight
                / 2 - radius, null);
    }

    /**
     * 獲取裁剪後的圓形圖片
     * 
     * @param radius半徑
     */
    public Bitmap getCroppedRoundBitmap(Bitmap bmp, int radius)
    {
        Bitmap scaledSrcBmp;
        int diameter = radius * 2;
        // 爲了防止寬高不相等，造成圓形圖片變形，因此截取長方形中處於中間位置最大的正方形圖片
        int bmpWidth = bmp.getWidth();
        int bmpHeight = bmp.getHeight();
        int squareWidth = 0, squareHeight = 0;
        int x = 0, y = 0;
        Bitmap squareBitmap;
        if (bmpHeight > bmpWidth)
        {// 高大於寬
            squareWidth = squareHeight = bmpWidth;
            x = 0;
            y = (bmpHeight - bmpWidth) / 2;
            // 截取正方形圖片
            squareBitmap =
                    Bitmap.createBitmap(bmp, x, y, squareWidth, squareHeight);
        } else if (bmpHeight < bmpWidth)
        {// 寬大於高
            squareWidth = squareHeight = bmpHeight;
            x = (bmpWidth - bmpHeight) / 2;
            y = 0;
            squareBitmap =
                    Bitmap.createBitmap(bmp, x, y, squareWidth, squareHeight);
        } else
        {
            squareBitmap = bmp;
        }
        if (squareBitmap.getWidth() != diameter
                || squareBitmap.getHeight() != diameter)
        {
            scaledSrcBmp =
                    Bitmap.createScaledBitmap(squareBitmap, diameter, diameter,
                            true);
        } else
        {
            scaledSrcBmp = squareBitmap;
        }
        Bitmap output =
                Bitmap.createBitmap(scaledSrcBmp.getWidth(),
                        scaledSrcBmp.getHeight(), Config.ARGB_8888);
        Canvas canvas = new Canvas(output);

        Paint paint = new Paint();
        Rect rect =
                new Rect(0, 0, scaledSrcBmp.getWidth(),
                        scaledSrcBmp.getHeight());

        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        canvas.drawARGB(0, 0, 0, 0);
        canvas.drawCircle(scaledSrcBmp.getWidth() / 2,
                scaledSrcBmp.getHeight() / 2, scaledSrcBmp.getWidth() / 2,
                paint);
        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        canvas.drawBitmap(scaledSrcBmp, rect, rect, paint);
        bmp = null;
        squareBitmap = null;
        scaledSrcBmp = null;
        return output;
    }

    /**
     * 邊緣畫圓
     */
    private void drawCircleBorder(Canvas canvas, int radius, int color)
    {
        Paint paint = new Paint();
        /* 去鋸齒 */
        paint.setAntiAlias(true);
        paint.setFilterBitmap(true);
        paint.setDither(true);
        paint.setColor(color);
        /* 設置paint的　style　爲STROKE：空心 */
        paint.setStyle(Paint.Style.STROKE);
        /* 設置paint的外框寬度 */
        paint.setStrokeWidth(mBorderThickness);
        canvas.drawCircle(defaultWidth / 2, defaultHeight / 2, radius, paint);
    }
}

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定義自己的屬性配置文件：attr.xml

<?xml version="1.0" encoding="utf-8"?> 
<resources> 
    <declare-styleable name="roundedimageview"> 
        <attr name="border_thickness" format="dimension" /> 
        <attr name="border_inside_color" format="color" /> 
        <attr name="border_outside_color" format="color"></attr> 
    </declare-styleable> 
</resources>

---

在xml配置中使用控件：activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="horizontal" 
    > 

    <!-- 沒有指定圓形ImageView屬性時，默認沒有外邊圓顏色 --> 
    <!-- 需要將圖片資源自定爲src ，或在程序中setImageResource(res) 不能設置background爲圖片，這樣不能達到圓形效果--> 
    <com.ine.view.tool.RoundImageView
        android:layout_width="100dp" 
        android:layout_height="100dp" 
        android:src="@drawable/img" 
        /> 
    <!-- border_outside_color 外部圓圈的顏色 --> 
    <!-- border_inside_color 內部部圓圈的顏色 --> 
    <!-- border_thickness 外圓和內圓的寬度 --> 
    <com.ine.view.tool.RoundImageView
        android:layout_width="100dp" 
        android:layout_height="100dp" 
        android:src="@drawable/img" 
        imagecontrol:border_inside_color="#bc0978" 
        imagecontrol:border_outside_color="#ba3456" 
        imagecontrol:border_thickness="1dp" 
        /> 
</LinearLayout>