本文的控件來自：http://blog.csdn.net/alan_biao/article/details/17379925
這個控件不同於之前介紹過的那個框架，這個僅僅能過將圖片裁剪爲圓形，沒能弄成橢圓，也沒有android:scaleType屬性。但他可以提供兩重邊框，對於簡單的使用來說，是完全夠用的。
使用方式和之前一樣，首先先配置attrs.xml
<!-- border_thickness 設置邊框的寬度 border_inside_color 設置內邊框的顏色 border_outside_color 設置外邊框的顏色 內外邊框如果只設置一個的話，則認爲只顯示一個邊框。 --> <declare-styleable name="RoundImageView"> <attr name="border_thickness" format="dimension" /> <attr name="border_inside_color" format="color" /> <attr name="border_outside_color" format="color" /> </declare-styleable>
然後建立類RoundImageView.java
package com.eva.views; 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; /** * 圓形ImageView，可設置最多兩個寬度不同且顏色不同的圓形邊框。 * 來源的博客：http://blog.csdn.net/alan_biao/article/details/17379925 * @author Alan */ 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;//圖片的外邊界 private int mBorderInsideColor = 0;//圖片的內邊界 // 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.RoundImageView); //邊界的寬度 mBorderThickness = a.getDimensionPixelSize( R.styleable.RoundImageView_border_thickness, 0); //外邊界的顏色 mBorderOutsideColor = a.getColor( R.styleable.RoundImageView_border_outside_color,defaultColor); //內邊界的顏色 mBorderInsideColor = a.getColor( R.styleable.RoundImageView_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(); } // 保證重新讀取圖片後不會因爲圖片大小而改變控件寬、高的大小（針對寬、高爲wrap_content佈局的imageview，但會導致margin無效） // if (defaultWidth != 0 && defaultHeight != 0) { // LinearLayout.LayoutParams params = new LinearLayout.LayoutParams( // defaultWidth, defaultHeight); // setLayoutParams(params); // } 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); // bitmap回收(recycle導致在佈局文件XML看不到效果) // bmp.recycle(); // squareBitmap.recycle(); // scaledSrcBmp.recycle(); 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); } }
最後，在佈局文件中設置該控件（需要添加命名空間）
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:pv="http://schemas.android.com/apk/res/com.eva.views" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#d6d6d6" android:orientation="vertical" > <com.eva.views.RoundImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:src="@drawable/kale" android:layout_marginTop="16dp" android:layout_gravity="center_horizontal" pv:border_thickness="3dp" pv:border_inside_color="#50c0e9"/> <com.eva.views.RoundImageView android:id="@+id/image_id" android:layout_width="150dp" android:layout_height="150dp" android:src="@drawable/kale" android:layout_marginTop="16dp" android:layout_gravity="center_horizontal" pv:border_thickness="4dp" pv:border_inside_color="#50c0e9" pv:border_outside_color="#ffc641"/> <com.eva.views.RoundImageView android:layout_width="100dp" android:layout_height="100dp" android:src="@drawable/kale" android:layout_marginTop="16dp" android:layout_gravity="center_horizontal" pv:border_thickness="3dp" pv:border_inside_color="#d6d6d6" pv:border_outside_color="#ffc641"/> </LinearLayout>
我們在代碼中可以和用ImageView一樣來設置圖片
RoundImageView imageView = (RoundImageView)findViewById(R.id.image_id);
imageView.setImageDrawable(getResources().getDrawable(R.drawable.saber));
imageView.setImageResource(R.drawable.saber);
