public class ImageUtil { /** * 旋转图片 * @param angle 旋转角度 * @param bitmap 要处理的Bitmap * @return 处理后的Bitmap */ public static Bitmap rotaingImageView(int angle, Bitmap bitmap) { // 旋转图片 动作 Matrix matrix = new Matrix(); matrix.postRotate(angle); // 创建新的图片 Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true); if (resizedBitmap != bitmap && !bitmap.isRecycled()){ bitmap.recycle(); //bitmap = null; } return resizedBitmap; } /** * 设置水印图片在左上角 * @param context * @param src * @param watermark * @param paddingLeft * @param paddingTop * @return */ public static Bitmap createWaterMaskLeftTop( Context context, Bitmap src, Bitmap watermark, int paddingLeft, int paddingTop) { return createWaterMaskBitmap(src, watermark, dp2px(context, paddingLeft), dp2px(context, paddingTop)); } private static Bitmap createWaterMaskBitmap(Bitmap src, Bitmap watermark, int paddingLeft, int paddingTop) { if (src == null) { return null; } int width = src.getWidth(); int height = src.getHeight(); //创建一个bitmap Bitmap newb = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);// 创建一个新的和SRC长度宽度一样的位图 //将该图片作为画布 Canvas canvas = new Canvas(newb); //在画布 0，0坐标上开始绘制原始图片 canvas.drawBitmap(src, 0, 0, null); //在画布上绘制水印图片 canvas.drawBitmap(watermark, paddingLeft, paddingTop, null); // 保存 canvas.save(Canvas.ALL_SAVE_FLAG); // 存储 canvas.restore(); return newb; } /** * 设置水印图片在右下角 * @param context * @param src * @param watermark * @param paddingRight * @param paddingBottom * @return */ public static Bitmap createWaterMaskRightBottom( Context context, Bitmap src, Bitmap watermark, int paddingRight, int paddingBottom) { return createWaterMaskBitmap(src, watermark, src.getWidth() - watermark.getWidth() - dp2px(context, paddingRight), src.getHeight() - watermark.getHeight() - dp2px(context, paddingBottom)); } /** * 设置水印图片到右上角 * @param context * @param src * @param watermark * @param paddingRight * @param paddingTop * @return */ public static Bitmap createWaterMaskRightTop( Context context, Bitmap src, Bitmap watermark, int paddingRight, int paddingTop) { return createWaterMaskBitmap( src, watermark, src.getWidth() - watermark.getWidth() - dp2px(context, paddingRight), dp2px(context, paddingTop)); } /** * 设置水印图片到左下角 * @param context * @param src * @param watermark * @param paddingLeft * @param paddingBottom * @return */ public static Bitmap createWaterMaskLeftBottom( Context context, Bitmap src, Bitmap watermark, int paddingLeft, int paddingBottom) { return createWaterMaskBitmap(src, watermark, dp2px(context, paddingLeft), src.getHeight() - watermark.getHeight() - dp2px(context, paddingBottom)); } /** * 设置水印图片到中间 * @param src * @param src * @param watermark * @return */ public static Bitmap createWaterMaskCenter(Bitmap src, Bitmap watermark) { return createWaterMaskBitmap(src, watermark, (src.getWidth() - watermark.getWidth()) / 2, (src.getHeight() - watermark.getHeight()) / 2); } /** * 给图片添加文字到左上角 * @param context * @param bitmap * @param text * @return */ public static Bitmap drawTextToLeftTop(Context context, Bitmap bitmap, String text, int size, int color, int paddingLeft, int paddingTop) { Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(color); paint.setTextSize(dp2px(context, size)); Rect bounds = new Rect(); paint.getTextBounds(text, 0, text.length(), bounds); return drawTextToBitmap(context, bitmap, text, paint, bounds, dp2px(context, paddingLeft), dp2px(context, paddingTop) + bounds.height()); } /** * 绘制文字到右下角 * @param context * @param bitmap * @param text * @param size * @param color * @param paddingRight * @param paddingBottom * @return */ public static Bitmap drawTextToRightBottom(Context context, Bitmap bitmap, String text, int size, int color, int paddingRight, int paddingBottom) { Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(color); paint.setTextSize(dp2px(context, size)); Rect bounds = new Rect(); paint.getTextBounds(text, 0, text.length(), bounds); return drawTextToBitmap(context, bitmap, text, paint, bounds, bitmap.getWidth() - bounds.width() - dp2px(context, paddingRight), bitmap.getHeight() - dp2px(context, paddingBottom)); } /** * 绘制文字到右上方 * @param context * @param bitmap * @param text * @param size * @param color * @param paddingRight * @param paddingTop * @return */ public static Bitmap drawTextToRightTop(Context context, Bitmap bitmap, String text, int size, int color, int paddingRight, int paddingTop) { Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(color); paint.setTextSize(dp2px(context, size)); Rect bounds = new Rect(); paint.getTextBounds(text, 0, text.length(), bounds); return drawTextToBitmap(context, bitmap, text, paint, bounds, bitmap.getWidth() - bounds.width() - dp2px(context, paddingRight), dp2px(context, paddingTop) + bounds.height()); } /** * 绘制文字到左下方 * @param context * @param bitmap * @param text * @param size * @param color * @param paddingLeft * @param paddingBottom * @return */ public static Bitmap drawTextToLeftBottom(Context context, Bitmap bitmap, String text, int size, int color, int paddingLeft, int paddingBottom) { Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(color); paint.setTextSize(dp2px(context, size)); Rect bounds = new Rect(); paint.getTextBounds(text, 0, text.length(), bounds); return drawTextToBitmap(context, bitmap, text, paint, bounds, dp2px(context, paddingLeft), bitmap.getHeight() - dp2px(context, paddingBottom)); } /** * 绘制文字到中间 * @param context * @param bitmap * @param text * @param size * @param color * @return */ public static Bitmap drawTextToCenter(Context context, Bitmap bitmap, String text, int size, int color) { Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); paint.setColor(color); paint.setTextSize(dp2px(context, size)); Rect bounds = new Rect(); paint.getTextBounds(text, 0, text.length(), bounds); return drawTextToBitmap(context, bitmap, text, paint, bounds, (bitmap.getWidth() - bounds.width()) / 2, (bitmap.getHeight() + bounds.height()) / 2); } //图片上绘制文字 private static Bitmap drawTextToBitmap(Context context, Bitmap bitmap, String text, Paint paint, Rect bounds, int paddingLeft, int paddingTop) { android.graphics.Bitmap.Config bitmapConfig = bitmap.getConfig(); paint.setDither(true); // 获取跟清晰的图像采样 paint.setFilterBitmap(true);// 过滤一些 if (bitmapConfig == null) { bitmapConfig = android.graphics.Bitmap.Config.ARGB_8888; } bitmap = bitmap.copy(bitmapConfig, true); Canvas canvas = new Canvas(bitmap); canvas.drawText(text, paddingLeft, paddingTop, paint); return bitmap; } /** * 缩放图片 * @param src * @param w * @param h * @return */ public static Bitmap scaleWithWH(Bitmap src, double w, double h) { if (w == 0 || h == 0 || src == null) { return src; } else { // 记录src的宽高 int width = src.getWidth(); int height = src.getHeight(); // 创建一个matrix容器 Matrix matrix = new Matrix(); // 计算缩放比例 float scaleWidth = (float) (w / width); float scaleHeight = (float) (h / height); // 开始缩放 matrix.postScale(scaleWidth, scaleHeight); // 创建缩放后的图片 return Bitmap.createBitmap(src, 0, 0, width, height, matrix, true); } } /** * dip转pix * @param context * @param dp * @return */ public static int dp2px(Context context, float dp) { final float scale = context.getResources().getDisplayMetrics().density; return (int) (dp * scale + 0.5f); } }
调取的方法很简单，就不多说了，只列举一个调用的小栗子吧：
Bitmap resultBitmap = ImageUtil.drawTextToRightBottom(context, result.crop(), "哈哈哈", 45, Color.RED, 20, 20);
对，就这么简单。在上面工具类中我都写了注释，以及各个参数代表什么意思都写了。
