页面加水印

深碍√TFBOYSˉ_ 2023-10-08 23:26 11阅读 0赞

[Android为页面添加水印\_x-dialog加上水印\_Fantasy丶Lin的博客-CSDN博客][Android_x-dialog_Fantasy_Lin_-CSDN]

import android.app.Activity;
    import android.graphics.Canvas;
    import android.graphics.ColorFilter;
    import android.graphics.Paint;
    import android.graphics.PixelFormat;
    import android.graphics.drawable.Drawable;
    import android.view.ViewGroup;
    import android.widget.FrameLayout;
    
    import androidx.annotation.IntRange;
    import androidx.annotation.NonNull;
    import androidx.annotation.Nullable;
    
    /**
     * 水印
     * <pre>
     *     author  : Fantasy
     *     version : 1.0, 2019-07-29
     *     since   : 1.0, 2019-07-29
     * </pre>
     */
    public class Watermark {
        /**
         * 水印文本
         */
        private String mText;
        /**
         * 字体颜色，十六进制形式，例如：0xAEAEAEAE
         */
        private int mTextColor;
        /**
         * 字体大小，单位为sp
         */
        private float mTextSize;
        /**
         * 旋转角度
         */
        private float mRotation;
        private static Watermark sInstance;
    
        private Watermark() {
            mText = "";
            mTextColor = 0xAEAEAEAE;
            mTextSize = 18;
            mRotation = -25;
        }
    
        public static Watermark getInstance() {
            if (sInstance == null) {
                synchronized (Watermark.class) {
                    sInstance = new Watermark();
                }
            }
            return sInstance;
        }
    
        /**
         * 设置水印文本
         *
         * @param text 文本
         * @return Watermark实例
         */
        public Watermark setText(String text) {
            mText = text;
            return sInstance;
        }
    
        /**
         * 设置字体颜色
         *
         * @param color 颜色，十六进制形式，例如：0xAEAEAEAE
         * @return Watermark实例
         */
        public Watermark setTextColor(int color) {
            mTextColor = color;
            return sInstance;
        }
    
        /**
         * 设置字体大小
         *
         * @param size 大小，单位为sp
         * @return Watermark实例
         */
        public Watermark setTextSize(float size) {
            mTextSize = size;
            return sInstance;
        }
    
        /**
         * 设置旋转角度
         *
         * @param degrees 度数
         * @return Watermark实例
         */
        public Watermark setRotation(float degrees) {
            mRotation = degrees;
            return sInstance;
        }
    
        /**
         * 显示水印，铺满整个页面
         *
         * @param activity 活动
         */
        public void show(Activity activity) {
            show(activity, mText);
        }
    
        /**
         * 显示水印，铺满整个页面
         *
         * @param activity 活动
         * @param text     水印
         */
        public void show(Activity activity, String text) {
            WatermarkDrawable drawable = new WatermarkDrawable();
            drawable.mText = text;
            drawable.mTextColor = mTextColor;
            drawable.mTextSize = mTextSize;
            drawable.mRotation = mRotation;
    
            ViewGroup rootView = activity.findViewById(android.R.id.content);
            FrameLayout layout = new FrameLayout(activity);
            layout.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.MATCH_PARENT));
            layout.setBackground(drawable);
            rootView.addView(layout);
        }
    
        private class WatermarkDrawable extends Drawable {
            private Paint mPaint;
            /**
             * 水印文本
             */
            private String mText;
            /**
             * 字体颜色，十六进制形式，例如：0xAEAEAEAE
             */
            private int mTextColor;
            /**
             * 字体大小，单位为sp
             */
            private float mTextSize;
            /**
             * 旋转角度
             */
            private float mRotation;
    
            private WatermarkDrawable() {
                mPaint = new Paint();
            }
    
            @Override
            public void draw(@NonNull Canvas canvas) {
                int width = getBounds().right;
                int height = getBounds().bottom;
                int diagonal = (int) Math.sqrt(width * width + height * height); // 对角线的长度
    
                mPaint.setColor(mTextColor);
                mPaint.setTextSize(spToPx(mTextSize)); // ConvertUtils.spToPx()这个方法是将sp转换成px，ConvertUtils这个工具类在我提供的demo里面有
                mPaint.setAntiAlias(true);
                float textWidth = mPaint.measureText(mText);
    
                canvas.drawColor(0x00000000);
                canvas.rotate(mRotation);
    
                int index = 0;
                float fromX;
                // 以对角线的长度来做高度，这样可以保证竖屏和横屏整个屏幕都能布满水印
                for (int positionY = diagonal / 10; positionY <= diagonal; positionY += diagonal / 10) {
                    fromX = -width + (index++ % 2) * textWidth; // 上下两行的X轴起始点不一样，错开显示
                    for (float positionX = fromX; positionX < width; positionX += textWidth * 2) {
                        canvas.drawText(mText, positionX, positionY, mPaint);
                    }
                }
    
                canvas.save();
                canvas.restore();
            }
    
            @Override
            public void setAlpha(@IntRange(from = 0, to = 255) int alpha) {
            }
    
            @Override
            public void setColorFilter(@Nullable ColorFilter colorFilter) {
            }
    
            @Override
            public int getOpacity() {
                return PixelFormat.TRANSLUCENT;
            }
    
        }
    public static int spToPx(float spValue) {
            float fontScale = Resources.getSystem().getDisplayMetrics().scaledDensity;
            return (int) (spValue * fontScale + 0.5f);
        }
    }

[Android_x-dialog_Fantasy_Lin_-CSDN]: https://blog.csdn.net/Fantasy_Lin_/article/details/97651171