鸿蒙Java开发模式11:鸿蒙图片裁剪功能的实现

鸿蒙入门指南，小白速来！从萌新到高手，怎样快速掌握鸿蒙开发？【课程入口】

目录：
1. 鸿蒙版图片裁剪功能效果展示
2.Java代码实现
3.裁剪工具类实现
4.《鸿蒙Java开发模式》系列文章合集

1. 鸿蒙版图片裁剪功能，效果如下:

   首页

图片裁剪区域:

裁剪结果：

2.Java代码实现如下:

package com.example.javahm9.slice;

import com.example.javahm9.ResourceTable;
import com.example.javahm9.util.CropImage;
import ohos.aafwk.ability.AbilitySlice;
import ohos.aafwk.content.Intent;
import ohos.agp.colors.RgbColor;
import ohos.agp.components.Button;
import ohos.agp.components.Component;
import ohos.agp.components.Text;
import ohos.agp.components.element.ShapeElement;

public class MainAbilitySlice extends AbilitySlice {

    //定义一个图片
    Component image;
    //定义一个文本
    Text text;

    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(ResourceTable.Layout_ability_main);

        //获取图片对象对应的component
        image = findComponentById(ResourceTable.Id_result_image);

        /*
         * 如果接收的cropFlag为true
         * 处理剪裁后的图片
         * 否则跳过
         */
        if(intent.getBooleanParam("cropFlag",false)){
            handleCrop(intent);
        }
        /* 自定义--获取文本对象对应的component
         * 根据intent里面的cropStatus来显示不同的文本
         * 0表示未接收到数据
         * 1表示剪裁取消
         * 2表示剪裁成功 有数据
         */
        text = (Text) findComponentById(ResourceTable.Id_text);
        if(intent.getIntParam("cropStatus",0) == 0){
            text.setText("欢迎使用");
        }else if(intent.getIntParam("cropStatus",0) == 1){
            text.setText("剪裁取消");
        }else if(intent.getIntParam("cropStatus",0) == 2){
            text.setText("剪裁成功");
        }


        //获取button对象对应的component
        Button button = (Button) findComponentById(ResourceTable.Id_button);
        // 设置button的属性及背景
        ShapeElement background = new ShapeElement();
       // background.setRgbColor(new RgbColor(125, 125, 255));
        background.setCornerRadius(25);
       // button.setBackground(background);
        if (button != null) {
            // 绑定点击事件
            button.setClickedListener(new Component.ClickedListener() {
                public void onClick(Component v) {
                    begincrop();
                }
            });
        }
    }

    public void begincrop(){
        CropImage.activity()
                .setContext(this)
                .setSource(ResourceTable.Media_a9)
                .setBundleName("com.example.javahm9")
                .setAbilityName("com.example.javahm9.MainAbility")
                .setRequset_code(1234)
                .start(super.getAbility(),this);
    }

    //处理剪裁结果
    private void handleCrop(Intent result) {
        int resultImg = result.getIntParam("resultImg",0);
        int result_code = result.getIntParam("result_code" , 0);
        if(resultImg != 0){
            CropImage.handleImage(result_code , image);

        }
    }

    @Override
    public void onActive() {
        super.onActive();
    }

    @Override
    public void onForeground(Intent intent) {
        super.onForeground(intent);
    }
}

3.裁剪工具类实现

package com.example.javahm9.util;

import ohos.aafwk.ability.Ability;
import ohos.aafwk.ability.AbilitySlice;
import ohos.aafwk.content.Intent;
import ohos.agp.components.Component;
import ohos.agp.render.Canvas;
import ohos.agp.render.Paint;
import ohos.agp.render.PixelMapHolder;
import ohos.app.Context;
import ohos.media.image.PixelMap;
import ohos.utils.net.Uri;

/**
 * @Author 李欣
 * 
 * 此类是一个工具类
 * 

 * 此类是面向于用户的 面向于MainAbilitySlice的
 * 

 * 此类提供设置一些参数的功能，提供了页面跳转，跳转到CropImageActivity的方法，有一些属性暂时用不到。
 */

public final class CropImage {

    //存一个context
    private static Context mContext;

    //图片资源文件
    private static int msource;

    //裁减结果
    public static final boolean CROPFLAG = true;

    //空的构造器
    private CropImage() {
    }

    //内部类初始化
    public static ActivityBuilder activity() {
        return new ActivityBuilder(null , null , null , 0);
    }

    /**
     * 这个方法对传进来的 component进行操作
     * 给这个空的component增加图片 旋转等等
     * @param result 一个参数用来判断返回的结果 以及如何处理
     * @param component 对这个component进行操作
     */
    public static void handleImage(int result, Component component) {

        //203表示裁剪成功（203为自定义的数字）
        if (result == 203) {
            //获得原始位图
            PixelMap pixelMap = BitmapUtils.getOriginalPixelMap(mContext , msource).get();

            //创建屏幕工具类 获得屏幕的宽度
            CropWindowHandler windowHandler = new CropWindowHandler(mContext);

            /**
             * 缩放指数 原始的图片的缩放大小
             * 数值为原始图片的宽度（pixelMap.getImageInfo().size.width）除以屏幕的宽度（windowHandler.getWindowWidth()） 的倒数
             */
            float ratio = (float) windowHandler.getWindowWidth()/(float) pixelMap.getImageInfo().size.width;

            //获得裁剪后的位图
            PixelMap cropped = CropOverlayView.getCroppedPixelMap();
            PixelMapHolder pixelMapHolder = new PixelMapHolder(cropped);

            //创建bitmaputils工具类，获得位图相关数据
            BitmapUtils bitmapUtils = new BitmapUtils(mContext, cropped, 400, msource);

            /**
             * 创建画位图的方法
             * 获取到之前的点击动作数组 这样就可以获得到具体最终的图片的方向
             * 并且依次按照图片方向进行旋转
             */
            Component.DrawTask drawTask = new Component.DrawTask() {
                @Override
                public void onDraw(Component component, Canvas canvas) {

                    //获得行为动作
                    int[] action = CropImageView.getActionResult();
                    //获得动作数目
                    int actionIndex = CropImageView.getActionIndexResult();
                    //循环执行旋转、翻转动作
                    for (int i = 0; i < actionIndex; i++) {
                        if (action[i] == 1) {
                            //rotate图像
                            canvas.rotate(90, bitmapUtils.getRealPixelMapWidth() / 2 * ratio, bitmapUtils.getRealPixelMapHeight() / 2 * ratio);
                        } else if (action[i] == 2) {
                            //水平翻转
                            //向下移动高度
                            canvas.translate(bitmapUtils.getRealPixelMapWidth() * ratio, 0);
                            //向y轴负方向缩放一倍
                            canvas.scale(-1f, 1f);
                        } else if (action[i] == 3) {
                            //垂直翻转
                            //向下移动高度
                            canvas.translate(0, bitmapUtils.getRealPixelMapHeight() * ratio);
                            //向y轴负方向缩放一倍
                            canvas.scale(1f, -1f);
                        }
                    }

                    //按照原来的比例进行缩放
                    canvas.scale(ratio , ratio);
                    //画图
                    canvas.drawPixelMapHolder(pixelMapHolder, 200, 230, new Paint());
                }
            };

            //为component增加drawtask方法
            component.addDrawTask(drawTask);
        }
    }

    public static PixelMap getCroppedPixelMap(){
        return CropOverlayView.getCroppedPixelMap();
    }

    public static final class ActivityBuilder {

        //设置图片的Uri
        private final Uri mSource;

        //需要跳转回的bundle的名字
        private String bundleName;

        //需要跳转回的Ability的名字
        private String abilityName;

        //request_code
        private int request_code;

        //初始化 记录一些信息
        private ActivityBuilder(Uri source , String bundle , String ability , int request) {
            mSource = source;
            bundleName = bundle;
            abilityName = ability;
            request_code = request;
        }

        //返回一个intent
        public Intent getIntent(Context context) {
            return getIntent(context, CropImageActivity.class);
        }

        //返回一个intent 用来实现页面跳转
        public Intent getIntent(Context context, Class cls) {
            Intent intent = new Intent();
            intent.setParam("source", msource);
            if(bundleName != null){
                intent.setParam("bundleName" , bundleName);
            }
            if(abilityName != null){
                intent.setParam("abilityName" , abilityName);
            }
            if(request_code != 0){
                intent.setParam("request_code" , request_code);
            }
            return intent;
        }

        //页面跳转
        public void start(Ability ability, AbilitySlice abilitySlice) {
            start(ability, abilitySlice, request_code);
        }

        //页面跳转
        public void start(Ability ability, AbilitySlice abilitySlice, int requestCode) {
            //给crop添加操作
            AbilitySlice cropImageAbilitySlice = new CropImageActivity();
            abilitySlice.presentForResult(cropImageAbilitySlice, getIntent(ability), requestCode);
        }

        //设置资源图片，被裁减的图片的id
        public ActivityBuilder setSource(int source) {
            msource = source;
            return this;
        }

        //设置context
        public ActivityBuilder setContext(Context context) {
            mContext = context;
            return this;
        }

        //设置需要跳转回的bundle名字
        public ActivityBuilder setBundleName(String s){
            bundleName = s;
            return this;
        }

        //设置需要跳转回的ability名字
        public ActivityBuilder setAbilityName(String s){
            abilityName = s;
            return this;
        }

        //设置需要跳转回时的code
        public ActivityBuilder setRequset_code(int i){
            request_code = i;
            return this;
        }

    }


}


package com.example.javahm9.util;

import ohos.aafwk.ability.AbilitySlice;
import ohos.aafwk.content.Intent;
import ohos.aafwk.content.Operation;
import ohos.agp.colors.RgbColor;
import ohos.agp.components.Button;
import ohos.agp.components.Component;
import ohos.agp.components.DependentLayout;
import ohos.agp.components.element.ShapeElement;
import ohos.agp.utils.RectFloat;
import ohos.bundle.AbilityInfo;
import ohos.media.image.PixelMap;

import static ohos.agp.components.ComponentContainer.LayoutConfig.MATCH_PARENT;

/**
 * @Author 李欣
 *
 * 此类为裁剪功能实现的主要页面
 *
 * 此页面上显示了一些功能性的button
 * 还有被裁减图片以及裁剪框
 */

public class CropImageActivity extends AbilitySlice {

    //定义此slice的Dependent布局
    private DependentLayout myLayout = new DependentLayout(this);

    //被裁减图片
    private Component mPicture;

    //被裁减图片的位图
    private PixelMap mPixelMap;

    //位图工具类
    private BitmapUtils mBitmapUtils;

    //屏幕工具类
    private CropWindowHandler mCropWindowHandler;

    //裁剪框
    private Component mCropBound;

    //裁剪框工具类
    private CropOverlayView mCropOverlayView;

    //图片资源
    private int mSource;

    //图片上边距
    private final int topIndex = 400;

    //图片工具类
    private CropImageView mCropImageView;

    //裁减结果的矩阵
    public static RectFloat croppedRectFloat;

    //裁减结果的pixelmap
    public static PixelMap croppedPixelMap;

    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);

        //创建本slice的布局文件
        DependentLayout.LayoutConfig config = new DependentLayout.LayoutConfig(MATCH_PARENT, MATCH_PARENT);

        //设置默认竖屏
        setDisplayOrientation(AbilityInfo.DisplayOrientation.PORTRAIT);
        //设置布局的背景
        myLayout.setLayoutConfig(config);
        ShapeElement element = new ShapeElement();
        element.setRgbColor(new RgbColor(255, 255, 255));
        myLayout.setBackground(element);

        //设置button,image等
        setupViews(intent);

        //加载裁剪框、背景图片等等
        loadInput();

        //加载布局
        super.setUIContent(myLayout);
    }

    //按钮和图片初始化
    private void setupViews(Intent intent) {
        buttonInit(intent);
        imageInit(intent);
    }

    //按钮初始化
    private void buttonInit(Intent intent) {
        //创建button
        Button cancel = cancelButton(intent);
        Button rotate = rotateButton();
//        Button horfilp = horizontalFilpButton();
//        Button verfilp =  verticalFilpButton();

        Button crop = cropButton(intent);

        //将button添加到布局
        myLayout.addComponent(cancel);
        myLayout.addComponent(rotate);
//        myLayout.addComponent(horfilp);
//        myLayout.addComponent(verfilp);
        myLayout.addComponent(crop);
    }

    //取消按钮
    private Button cancelButton(Intent intent) {
        //创建取消button
        Button cancel = new Button(this);
        //为button增加布局条件
        DependentLayout.LayoutConfig cancelLayoutConfig = new DependentLayout.LayoutConfig();
        cancelLayoutConfig.setMargins(140, 50, 0, 0);
        cancelLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_TOP);
        cancelLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_PARENT_LEFT);
        //设置背景颜色
        cancel.setLayoutConfig(cancelLayoutConfig);
        ShapeElement cancelElement = new ShapeElement();
        cancelElement.setRgbColor(new RgbColor(155, 155, 155));
        cancelElement.setCornerRadius(25);
        cancel.setBackground(cancelElement);
        //设置文本
        cancel.setText("取消");
        cancel.setTextSize(55);
        cancel.setHeight(180);
        cancel.setWidth(220);
        //绑定点击方法
        cancel.setClickedListener(new Component.ClickedListener() {
            public void onClick(Component v) {
                //为按钮绑定方法
                cancel(intent);
            }
        });

        return cancel;
    }

    //旋转按钮
    private Button rotateButton() {
        //创建旋转button
        Button rotate = new Button(this);
        //为button增加布局条件
        DependentLayout.LayoutConfig rotateLayoutConfig = new DependentLayout.LayoutConfig();
        rotateLayoutConfig.setMargins(500, 50, 0, 0);
        rotateLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_TOP);
        rotateLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_PARENT_LEFT);
        rotate.setLayoutConfig(rotateLayoutConfig);
        //设置背景颜色
        ShapeElement rotateElement = new ShapeElement();
        rotateElement.setRgbColor(new RgbColor(255, 228, 181));
        rotateElement.setCornerRadius(25);
        rotate.setBackground(rotateElement);
        //设置文本
        rotate.setText("旋转");
        rotate.setTextSize(55);
        rotate.setHeight(180);
        rotate.setWidth(220);
        //绑定点击方法
        rotate.setClickedListener(new Component.ClickedListener() {
            public void onClick(Component v) {
                rotate();
            }
        });

        return rotate;
    }

    //水平翻转按钮
    private Button horizontalFilpButton() {
        //创建翻转button
        Button filp = new Button(this);
        //为button增加布局条件
        DependentLayout.LayoutConfig filpLayoutConfig = new DependentLayout.LayoutConfig();
        filpLayoutConfig.setMargins(0, 50, 300, 0);
        filpLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_TOP);
        filpLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_PARENT_RIGHT);
        //设置背景颜色
        filp.setLayoutConfig(filpLayoutConfig);
        ShapeElement filpElement = new ShapeElement();
        filpElement.setRgbColor(new RgbColor(180, 238, 180));
        filpElement.setCornerRadius(25);
        filp.setBackground(filpElement);
        //设置文本
        filp.setText("horFilp");
        filp.setTextSize(40);
        filp.setHeight(85);
        filp.setWidth(220);
        //绑定点击方法
        filp.setClickedListener(new Component.ClickedListener() {
            public void onClick(Component v) {
                horizontalFlip();
            }
        });

        return filp;
    }

    //垂直翻转按钮
    private Button verticalFilpButton() {
        //创建翻转button
        Button filp = new Button(this);
        //为button增加布局条件
        DependentLayout.LayoutConfig filpLayoutConfig = new DependentLayout.LayoutConfig();
        filpLayoutConfig.setMargins(0, 145, 300, 0);
        filpLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_TOP);
        filpLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_PARENT_RIGHT);
        //设置背景颜色
        filp.setLayoutConfig(filpLayoutConfig);
        ShapeElement filpElement = new ShapeElement();
        filpElement.setRgbColor(new RgbColor(180, 238, 180));
        filpElement.setCornerRadius(25);
        filp.setBackground(filpElement);
        //设置文本
        filp.setText("verFilp");
        filp.setTextSize(40);
        filp.setHeight(85);
        filp.setWidth(220);
        //绑定点击方法
        filp.setClickedListener(new Component.ClickedListener() {
            public void onClick(Component v) {
                verticalFlip();
            }
        });

        return filp;
    }

    //裁剪按钮
    private Button cropButton(Intent intent) {
        //创建裁剪button
        Button crop = new Button(this);
        //为button增加布局条件
        DependentLayout.LayoutConfig cropLayoutConfig = new DependentLayout.LayoutConfig();
        cropLayoutConfig.setMargins(820, 50, 0, 0);
        cropLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_TOP);
        cropLayoutConfig.addRule(DependentLayout.LayoutConfig.ALIGN_PARENT_LEFT);
        //设置背景颜色
        crop.setLayoutConfig(cropLayoutConfig);
        ShapeElement cropElement = new ShapeElement();
        cropElement.setRgbColor(new RgbColor(0, 125, 155));
        cropElement.setCornerRadius(25);
        crop.setBackground(cropElement);
        //设置文本
        crop.setText("裁剪");
        crop.setTextSize(55);
        crop.setHeight(180);
        crop.setWidth(220);
        //绑定点击方法
        crop.setClickedListener(new Component.ClickedListener() {
            public void onClick(Component v) {
                crop(intent);
            }
        });

        return crop;
    }

    //图片初始化
    private void imageInit(Intent intent) {

        //获得图片的id
        int source = intent.getIntParam("source", 0);
        mSource = source;

        //根据图片id获取pixelmap
        PixelMap pixelMapOriginal = BitmapUtils.getOriginalPixelMap(this, mSource).get();
        mPixelMap = pixelMapOriginal;

        //创建bitmaputils工具类，获得位图相关数据
        BitmapUtils bitmapUtils = new BitmapUtils(this , mPixelMap ,topIndex , mSource );

        //创建cropwindowhandler工具类，获得windows相关数据
        CropWindowHandler cropWindowHandler = new CropWindowHandler(this);

        //创建图片工具类，用来获得图片
        mCropImageView = new CropImageView(mPixelMap , this ,  mSource , topIndex);

        //获取展示图片的component
        mPicture = mCropImageView.getmPicture();

        //计算图片的位置，使得图片居中显示，计算出图片距离屏幕左边的空白
        int margin = cropWindowHandler.getWindowWidth()/2 - bitmapUtils.getPixelMapWidth()/2;

        //给mPicture增加布局
        DependentLayout.LayoutConfig componentLayoutConfig = new DependentLayout.LayoutConfig();
        componentLayoutConfig.setMargins(0, topIndex, 0, 0);//边距
        mPicture.setLayoutConfig(componentLayoutConfig);

        //将图片加入布局
        myLayout.addComponent(mPicture);

    }

    //初始化工具类，加载裁剪框等等
    private void loadInput() {

        //创建位图工具类
        mBitmapUtils = new BitmapUtils(this, mPixelMap, 400, mSource);

        //创建屏幕工具类
        mCropWindowHandler = new CropWindowHandler(this);

        //创建裁剪框的工具类
        mCropOverlayView = new CropOverlayView(this, mBitmapUtils, mCropWindowHandler);

        //获得裁剪框
        mCropBound = mCropOverlayView.getmCropBound();

        //将裁剪框加入布局文件
        myLayout.addComponent(mCropBound);
    }

    //取消裁剪方法
    private void cancel(Intent intentOriginal) {
        Intent intent = new Intent();

        //增加裁剪状态及结果
        intent.setParam("cropFlag", !CropImage.CROPFLAG);
        intent.setParam("cropStatus", 1);

        // 通过Intent中的OperationBuilder类构造operation对象，指定设备标识（空串表示当前设备）、应用包名、Ability名称
        Operation operation = new Intent.OperationBuilder()
                .withDeviceId("")
                .withBundleName(intentOriginal.getStringParam("bundleName"))
                .withAbilityName(intentOriginal.getStringParam("abilityName"))
                .build();
        // 把operation设置到intent中
        intent.setOperation(operation);

        //跳转
        startAbility(intent);
    }

    //图片旋转的方法
    private void rotate(){
        //图片旋转
        mCropImageView.rotateOnce();
        //裁剪框旋转
        mCropOverlayView.rotateOnce();
    }

    //图片水平翻转的方法
    private void horizontalFlip(){
        //图片翻转
        mCropImageView.horizontalFilp();
        //裁剪框翻转
        mCropOverlayView.horizontalFilpOnce();
    }

    //图片垂直翻转的方法
    private void verticalFlip(){
        mCropImageView.verticalFilp();
        //裁剪框翻转
        mCropOverlayView.verticalFilpOnce();
    }

    //成功裁剪方法
    private void crop(Intent intentOriginal) {

        //计算裁减后的pixelmap并存放于cropoverlayview中
        mCropOverlayView.croppedPixel(this);

        //显示到MainActivity
        Intent intent = new Intent();

        //增加裁剪状态及结果
        intent.setParam("cropFlag", CropImage.CROPFLAG);
        intent.setParam("cropStatus", 2);
        intent.setParam("result_code" , 203);

        RectFloat cropRect = mCropOverlayView.getmCropRect();
        //塞入裁剪结果
        intent.setParam("resultImg", mSource);
        croppedRectFloat = mCropOverlayView.getmCropRect();
        croppedPixelMap = mPixelMap;

        // 通过Intent中的OperationBuilder类构造operation对象，指定设备标识（空串表示当前设备）、应用包名、Ability名称
        Operation operation = new Intent.OperationBuilder()
                .withDeviceId("")
                .withBundleName(intentOriginal.getStringParam("bundleName"))
                .withAbilityName(intentOriginal.getStringParam("abilityName"))
                .build();
        // 把operation设置到intent中
        intent.setOperation(operation);

        //跳转
        startAbility(intent);

    }

    @Override
    protected void onStop() {
        super.onStop();
    }
}

作者：六合李欣
想了解更多内容，请访问： 51CTO和华为官方战略合作共建的鸿蒙技术社区https://harmonyos.51cto.com