Android为图片添加水印，裁剪图片，旋转图片工具类

妖狐艹你老母 2022-05-07 20:18 310阅读 0赞

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。不会的可以留言。