Android实现水印

package com.cjq.picturemarkerdemo;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RadioGroup;
import android.widget.RelativeLayout;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.viewpager.widget.PagerAdapter;
import androidx.viewpager.widget.ViewPager;

import java.util.ArrayList;
import java.util.List;

public class ViewPagerActivity extends Activity {

    private PagerAdapter mPagerAdapter;//适配器
    private List imageList;
    List bitmaps;
    private int mPosition;
    List stringTexts;



    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_viewpager);
        water1();
    }


    private void water1() {
        stringTexts = new ArrayList<>();
        stringTexts.add("工单号 : JS200000000000000");
        stringTexts.add("工程师 : 肖宇");
        stringTexts.add("经度: 6666 ,纬度：9999");
        stringTexts.add("备注:");
        Bitmap sourBitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.water_bg);
        Bitmap sourBitmap2 = BitmapFactory.decodeResource(getResources(), R.drawable.test_water2);
        ViewPager viewPager = findViewById(R.id.view_pager);
        Button button = findViewById(R.id.btn_water);
        Button button1 = findViewById(R.id.btn_beizhu);
        bitmaps = new ArrayList<>();
        for (int i = 0; i < 1000; i++) {
            bitmaps.add(sourBitmap2);
        }
        bitmaps.add(sourBitmap1);
        bitmaps.add(sourBitmap2);
        imageList = new ArrayList<>();


        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                mPosition = position;
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

        mPagerAdapter = new PagerAdapter() {
            @Override
            public int getCount() {
                return bitmaps.size();
            }

            @Override
            public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
                return view == object;
            }

            @Override
            public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
                container.removeView(imageList.get(position));
            }

            @NonNull
            @Override
            public Object instantiateItem(@NonNull ViewGroup container, int position) {
                ImageView imageView = new ImageView(ViewPagerActivity.this);
                imageView.setTag(position);
                imageView.setImageBitmap(bitmaps.get(position));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                container.addView(imageView);
                imageList.add(imageView);
                return imageView;
            }

            @Override
            public int getItemPosition(@NonNull Object object) {
                View view = (View) object;
                if (mPosition == (Integer) view.getTag()) {
                    return POSITION_NONE;
                } else {
                    return POSITION_UNCHANGED;
                }
            }
        };
        viewPager.setAdapter(mPagerAdapter);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                doWater(false);

            }
        });



        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(ViewPagerActivity.this, EditRemarks.class);
                ViewPagerActivity.this.startActivityForResult(intent, 1001);
            }
        });

    }



    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (data != null) {
            String remark = data.getStringExtra("remark");

            stringTexts.set(stringTexts.size() -1, "备注 : " + remark);
            doWater(true);
            doWater(false);
        }

    }

    private  void doWater(boolean isClear){
        Bitmap bitmap = bitmaps.get(mPosition);

        Bitmap bitmap1 = BitmapFactory.decodeResource(getResources(), R.drawable.test_water2);

        Bitmap water = ImageUtil.drawTextToLeftBottom(ViewPagerActivity.this, bitmap, stringTexts, 12, Color.RED, 30, 30, isClear);
        if (isClear) {
            bitmaps.set(mPosition, bitmap1);
        } else {
            bitmaps.set(mPosition, water);
        }

        ImageView imageView = new ImageView(ViewPagerActivity.this);
        imageView.setImageBitmap(bitmaps.get(mPosition));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageList.set(mPosition, imageView);
        mPagerAdapter.notifyDataSetChanged();
    }
}

package com.cjq.picturemarkerdemo;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import androidx.annotation.Nullable;

public class EditRemarks extends Activity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.edit_remarks_activity);
        initView();
    }

    private void initView() {
        Button cancelButton = findViewById(R.id.cancel_button);
        Button completeButton = findViewById(R.id.complete_button);
        EditText editText = findViewById(R.id.edit_remark);

        cancelButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });

        completeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String s = editText.getText().toString();
                Intent intent = new Intent();
                intent.putExtra("remark", s);
                setResult(RESULT_OK, intent);
                finish();
            }
        });
    }
}

package com.cjq.picturemarkerdemo;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.Log;

import java.util.ArrayList;
import java.util.List;


public class ImageUtil {




    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));
    }

    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 newBitmap = Bitmap.createBitmap(width, height, 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(newBitmap);
        //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();
        // 存储
        canvas.restore();
        return newBitmap;
    }


    
    public static Bitmap drawTextToLeftBottom(Context context, Bitmap bitmap, List text,
                                              int size, int color, int paddingLeft, int paddingBottom, boolean isClear) {
        Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(color);
        paint.setTextSize(dp2px(context, size));
        Rect bounds = new Rect();


        return drawTextToBitmap(context, bitmap, text, paint, bounds,
                dp2px(context, paddingLeft),
                bitmap.getHeight() - dp2px(context, paddingBottom), isClear);
    }



    
    private static Bitmap drawTextToBitmap(Context context, Bitmap bitmap,List text,
                                           Paint paint, Rect bounds, int paddingLeft, int paddingBottom, boolean isClear) {
        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 = Config.ARGB_8888;
        }
        bitmap = bitmap.copy(bitmapConfig, true);
        Canvas canvas = new Canvas(bitmap);
        if (isClear) {

        } else {
            for (int i = 0; i< text.size(); i++ ) {
                paint.getTextBounds(text.get(i), 0, text.get(i).length(), bounds);
                canvas.drawText(text.get(i), paddingLeft, paddingBottom - (text.size()-1 -i) * dp2px(context,20), paint);
            }
        }


        return bitmap;
    }



    
    public static int dp2px(Context context, float dp) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dp * scale + 0.5f);
    }
}

edit_remarks_activity

colors

#99000000

styles