在Android开发中经常需要图标上以及甚至在应用图标的快捷方式上显示数字，表示未读消息数以及在以及在某条信息右上角标志小圆形，表示这条消息是未读的状态等等，之前对此内容不熟悉的时候也表示困扰，现在对图片一些操作也写在一个工具类中，以方便调用。
来看一下最终效果图：
BitmapUtil.class
package com.xiaolijuan.bitmapdome.utils;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.Typeface;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.RoundRectShape;
import android.text.TextUtils;
import android.util.DisplayMetrics;
import android.util.TypedValue;
/**
* @author: xiaolijuan
* @description: 图片工具类
* @projectName: BitmapDome
* @date: 2016-01-19
* @time: 21:48
*/
public class BitmapUtil {
// 默认圆角半径
private static final int DEFAULT_CORNER_RADIUS_DIP = 8;
// 默认边框宽度
private static final int DEFAULT_STROKE_WIDTH_DIP = 2;
// 边框的颜色
private static final int DEFAULT_STROKE_COLOR = Color.WHITE;
// 中间数字的颜色
private static final int DEFAULT_NUM_COLOR = Color.parseColor("#CCFF0000");
/**
* 生成有数字的图片(没有边框)
*
* @param context 上下文
* @param icon 图片
* @param isShowNum 是否要绘制数字
* @param num 数字字符串：整型数字 超过99，显示为"99+"
* @return 重新生成带数字的图片
*/
public static Bitmap generatorNumIcon2(Context context, Bitmap icon,
boolean isShowNum, String num) {
DisplayMetrics dm = context.getResources().getDisplayMetrics();
// 基准屏幕密度
float baseDensity = 2.3f;
float factor = dm.density / baseDensity;
// 初始化画布
int iconSize = (int) context.getResources().getDimension(
android.R.dimen.app_icon_size);
Bitmap numIcon = Bitmap.createBitmap(iconSize, iconSize,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(numIcon);
// 拷贝图片
Paint iconPaint = new Paint();
iconPaint.setDither(true);// 防抖动
iconPaint.setFilterBitmap(true);// 用来对Bitmap进行滤波处理，这样，当你选择Drawable时，会有抗锯齿的效果
Rect src = new Rect(0, 0, icon.getWidth(), icon.getHeight());
Rect dst = new Rect(0, 0, iconSize, iconSize);
canvas.drawBitmap(icon, src, dst, iconPaint);
if (isShowNum) {
if (TextUtils.isEmpty(num)) {
num = "0";
}
if (!TextUtils.isDigitsOnly(num)) {
// 非数字
num = "0";
}
int numInt = Integer.valueOf(num);
if (numInt > 99) {// 超过99
num = "99+";
}
// 启用抗锯齿和使用设备的文本字体大小
// 测量文本占用的宽度
Paint numPaint = new Paint(Paint.ANTI_ALIAS_FLAG
| Paint.DEV_KERN_TEXT_FLAG);
numPaint.setColor(Color.WHITE);
numPaint.setTextSize(20f * factor);
numPaint.setTypeface(Typeface.DEFAULT_BOLD);
int textWidth = (int) numPaint.measureText(num, 0, num.length());
/**
* 绘制圆角矩形背景
*/
int backgroundHeight = (int) (2 * 15 * factor);
int backgroundWidth = textWidth > backgroundHeight ? (int) (textWidth + 10 * factor)
: backgroundHeight;//圆角矩形背景的宽度
canvas.save();// 保存状态
ShapeDrawable drawable = getDefaultBackground(context);
drawable.setIntrinsicHeight(backgroundHeight);
drawable.setIntrinsicWidth(backgroundWidth);
drawable.setBounds(0, 0, backgroundWidth, backgroundHeight);
canvas.translate(iconSize - backgroundWidth, 0);
drawable.draw(canvas);
canvas.restore();// 重置为之前保存的状态
// 绘制数字
canvas.drawText(num,
(float) (iconSize - (backgroundWidth + textWidth) / 2),
22 * factor, numPaint);
}
return numIcon;
}
/**
* 生成有数字的图片(有边框的)
*
* @param context 上下文
* @param icon 图片
* @param isShowNum 是否要绘制数字
* @param num 数字字符串：整型数字 超过99，显示为"99+"
* @return 重新生成带数字的图片
*/
public static Bitmap generatorNumIcon3(Context context, Bitmap icon,
boolean isShowNum, String num) {
DisplayMetrics dm = context.getResources().getDisplayMetrics();
// 基准屏幕密度
float baseDensity = 2.2f;
float factor = dm.density / baseDensity;
// 初始化画布
int iconSize = (int) context.getResources().getDimension(
android.R.dimen.app_icon_size);
Bitmap numIcon = Bitmap.createBitmap(iconSize, iconSize,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(numIcon);
// 拷贝图片
Paint iconPaint = new Paint();
iconPaint.setDither(true);// 防抖动
iconPaint.setFilterBitmap(true);// 用来对Bitmap进行滤波处理，这样，当你选择Drawable时，会有抗锯齿的效果
Rect src = new Rect(0, 0, icon.getWidth(), icon.getHeight());
Rect dst = new Rect(0, 0, iconSize, iconSize);
canvas.drawBitmap(icon, src, dst, iconPaint);
if (isShowNum) {
if (TextUtils.isEmpty(num)) {
num = "0";
}
if (!TextUtils.isDigitsOnly(num)) {
// 非数字
num = "0";
}
int numInt = Integer.valueOf(num);
if (numInt > 99) {// 超过99
num = "99+";
}
// 启用抗锯齿和使用设备的文本字体大小
// 测量文本占用的宽度
Paint numPaint = new Paint(Paint.ANTI_ALIAS_FLAG
| Paint.DEV_KERN_TEXT_FLAG);
numPaint.setColor(Color.WHITE);
numPaint.setTextSize(20f * factor);
numPaint.setTypeface(Typeface.DEFAULT_BOLD);
int textWidth = (int) numPaint.measureText(num, 0, num.length());
/**
* 绘制圆角矩形背景：先画边框，再画内部的圆角矩形
*/
// 圆角矩形背景的宽度
int backgroundHeight = (int) (2 * 15 * factor);
int backgroundWidth = textWidth > backgroundHeight ? (int) (textWidth + 10 * factor)
: backgroundHeight;
// 边框的宽度
int strokeThickness = (int) (2 * factor);
canvas.save();// 保存状态
int strokeHeight = backgroundHeight + strokeThickness * 2;
int strokeWidth = textWidth > strokeHeight ? (int) (textWidth + 10
* factor + 2 * strokeThickness) : strokeHeight;
ShapeDrawable outStroke = getDefaultStrokeDrawable(context);
outStroke.setIntrinsicHeight(strokeHeight);
outStroke.setIntrinsicWidth(strokeWidth);
outStroke.setBounds(0, 0, strokeWidth, strokeHeight);
canvas.translate(iconSize - strokeWidth - strokeThickness,
strokeThickness);
outStroke.draw(canvas);
canvas.restore();// 重置为之前保存的状态
canvas.save();// 保存状态
ShapeDrawable drawable = getDefaultBackground(context);
drawable.setIntrinsicHeight((int) (backgroundHeight + 2 * factor));
drawable.setIntrinsicWidth((int) (backgroundWidth + 2 * factor));
drawable.setBounds(0, 0, backgroundWidth, backgroundHeight);
canvas.translate(iconSize - backgroundWidth - 2 * strokeThickness,
2 * strokeThickness);
drawable.draw(canvas);
canvas.restore();// 重置为之前保存的状态
// 绘制数字
canvas.drawText(
num,
(float) (iconSize
- (backgroundWidth + textWidth + 4 * strokeThickness)
/ 2 - 1), (22) * factor + 2 * strokeThickness,
numPaint);
}
return numIcon;
}
/**
* 圆角矩形，相当于用<shape>的xml的背景
*
* @param context 上下文
* @return
*/
private static ShapeDrawable getDefaultBackground(Context context) {
// 这个是为了应对不同分辨率的手机，屏幕兼容性
int r = dipToPixels(context, DEFAULT_CORNER_RADIUS_DIP);
float[] outerR = new float[]{r, r, r, r, r, r, r, r};
// 圆角矩形
RoundRectShape rr = new RoundRectShape(outerR, null, null);
ShapeDrawable drawable = new ShapeDrawable(rr);
drawable.getPaint().setColor(DEFAULT_NUM_COLOR);// 设置颜色
return drawable;
}
/**
* 圆角矩形，相当于用<shape>的xml的背景
*
* @param context 上下文
* @return
*/
private static ShapeDrawable getDefaultStrokeDrawable(Context context) {
// 这个是为了应对不同分辨率的手机，屏幕兼容性
int r = dipToPixels(context, DEFAULT_CORNER_RADIUS_DIP);
int distance = dipToPixels(context, DEFAULT_STROKE_WIDTH_DIP);
float[] outerR = new float[]{r, r, r, r, r, r, r, r};
// 圆角矩形
RoundRectShape rr = new RoundRectShape(outerR, null, null);
ShapeDrawable drawable = new ShapeDrawable(rr);
drawable.getPaint().setStrokeWidth(distance);
drawable.getPaint().setStyle(Paint.Style.FILL);
drawable.getPaint().setColor(DEFAULT_STROKE_COLOR);// 设置颜色
return drawable;
}
/**
* dp to px
*
* @param context 上下文
* @param dip
* @return
*/
public static int dipToPixels(Context context, int dip) {
Resources r = context.getResources();
float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dip,
r.getDisplayMetrics());
return (int) px;
}
/**
* 在原图右上角画圆形状态标志，其中icon为原图，color为所需状态标示的颜色，一般取值为"Color.**",r为所画圆的半径
*
* @param icon 原图
* @param res 获取Resources
* @param color 所需状态标示的颜色,一般取值为"Color.**"
* @param r 所画圆的半径
* @return
*/
public static Bitmap generatorStatusIcon(Bitmap icon, Resources res,
int color, int r) {
// 初始化画布
int iconSize = (int) res.getDimension(android.R.dimen.app_icon_size);
Bitmap contactIcon = Bitmap.createBitmap(iconSize, iconSize,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(contactIcon);
// 拷贝图片
Paint iconPaint = new Paint();
iconPaint.setDither(true);// 防抖动
iconPaint.setFilterBitmap(true);// 用来对Bitmap进行滤波处理，这样，当你选择Drawable时，会有抗锯齿的效果
Rect src = new Rect(0, 0, icon.getWidth(), icon.getHeight());
Rect dst = new Rect(0, 0, iconSize, iconSize);
canvas.drawBitmap(icon, src, dst, iconPaint);
Paint countPaint = new Paint(Paint.ANTI_ALIAS_FLAG
| Paint.DEV_KERN_TEXT_FLAG);
countPaint.setColor(color);
canvas.drawCircle(iconSize - r, r, r, countPaint);
return contactIcon;
}
/**
* 传入一张Bitmap型的方形图片使之变成圆形
*
* @param bitmap 图片
* @return
*/
public static Bitmap makeRoundCorner(Bitmap bitmap) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
int left = 0, top = 0, right = width, bottom = height;
float roundPx = height / 2;
if (width > height) {
left = (width - height) / 2;
top = 0;
right = left + height;
bottom = height;
} else if (height > width) {
left = 0;
top = (height - width) / 2;
right = width;
bottom = top + width;
roundPx = width / 2;
}
Bitmap output = Bitmap.createBitmap(width, height,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
int color = 0xff424242;
Paint paint = new Paint();
Rect rect = new Rect(left, top, right, bottom);
RectF rectF = new RectF(rect);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
/**
* 传入一张Bitmap型的方形图片使之变成圆角矩形，ratio值在1以上就很明显
*
* @param bitmap 图片
* @param ratio 比例，这里是宽高与半径的比例
* @return
*/
public static Bitmap toRoundCorner(Bitmap bitmap, float ratio) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
canvas.drawRoundRect(rectF, bitmap.getWidth() / ratio,
bitmap.getHeight() / ratio, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
/**
* 使bitmap图标边角圆弧化，pixels值在10以上才比较明显，变化慢
*
* @param bitmap 图片
* @param pixels 圆角的半径
* @return
*/
public static Bitmap toRoundCorner_1(Bitmap bitmap, int pixels) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
final float roundPx = pixels;
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
/**
* 在一张背景图片上合成四个头像
*
* @param backGroundIcon 背景图片
* @param res 获取Resources
* @param first 图片1
* @param second 图片2
* @param third 图片3
* @param four 图片4
* @return
*/
public static Bitmap add4Bitmap(Bitmap backGroundIcon, Resources res,
Bitmap first, Bitmap second, Bitmap third, Bitmap four) {
int iconSize = (int) res.getDimension(android.R.dimen.app_icon_size);
Bitmap contactIcon = Bitmap.createBitmap(iconSize, iconSize,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(contactIcon);
Paint iconPaint = new Paint();
iconPaint.setDither(true);// 防抖动
iconPaint.setFilterBitmap(true);// 用来对Bitmap进行滤波处理，这样，当你选择Drawable时，会有抗锯齿的效果
Rect src = new Rect(0, 0, backGroundIcon.getWidth(),
backGroundIcon.getHeight());
Rect dst = new Rect(0, 0, iconSize, iconSize);
canvas.drawBitmap(backGroundIcon, src, dst, iconPaint);
int width = iconSize / 2;
int height = iconSize / 2;
canvas.drawBitmap(pictureZoom(first, iconSize / 2, iconSize / 2), 0, 0,
iconPaint);
canvas.drawBitmap(pictureZoom(second, iconSize / 2, iconSize / 2),
width, 0, iconPaint);
canvas.drawBitmap(pictureZoom(third, iconSize / 2, iconSize / 2), 0,
height, iconPaint);
canvas.drawBitmap(pictureZoom(four, iconSize / 2, iconSize / 2), width,
height, iconPaint);
return contactIcon;
}
/**
* 图片缩放
*
* @param bitMap 原图片
* @param newWidth 新的宽
* @param newHeight 新的高
* @return
*/
public static Bitmap pictureZoom(Bitmap bitMap, int newWidth, int newHeight) {
int width = bitMap.getWidth();
int height = bitMap.getHeight();
// 计算缩放比例
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// 取得想要缩放的matrix参数
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
// 得到新的图片
bitMap = Bitmap.createBitmap(bitMap, 0, 0, width, height, matrix, true);
return bitMap;
}
/**
* 渲染成灰色图片
*
* @param bitmap 图片
* @return
*/
public static final Bitmap grey(Bitmap bitmap) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Bitmap faceIconGreyBitmap = Bitmap.createBitmap(width, height,
Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(faceIconGreyBitmap);
Paint paint = new Paint();
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.setSaturation(0);
ColorMatrixColorFilter colorMatrixFilter = new ColorMatrixColorFilter(
colorMatrix);
paint.setColorFilter(colorMatrixFilter);
canvas.drawBitmap(bitmap, 0, 0, paint);
return faceIconGreyBitmap;
}
}