Android圓形圖片--自定義控制元件

Android圓形圖片控制元件效果圖如下：

程式碼如下:

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，可設定最多兩個寬度不同且顏色不同的圓形邊框。
 * 設定顏色在xml佈局檔案中由自定義屬性配置引數指定
 */
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;
	// 控制元件預設長、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，分別為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;
		// 為了防止寬高不相等，造成圓形圖片變形，因此擷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;
			// 擷取正方形圖片
			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);
		/* 設定paint的　style　為STROKE：空心 */
		paint.setStyle(Paint.Style.STROKE);
		/* 設定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檔案：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配置中使用控制元件：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，預設沒有外邊圓顏色 -->
    <!-- 需要將圖片資源自定為src ，或在程式中setImageResource(res) 不能設定background為圖片，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>

3、主Activity中沒有相關程式碼，直接載入佈局檔案即可。