Android圓形圖片自定義控件

代碼如下:
RoundImageView.java

package com.dxd.roundimageview; 
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.util.Log; 
import android.widget.ImageView; 

import com.alan.myimageview.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); 
    } 

    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); 
    } 
}

1、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>

2、在xml配置中使用控件：activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    xmlns:imagecontrol="http://schemas.android.com/apk/res-auto" 
    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.dxd.roundimageview.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.dxd.roundimageview.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>