鸿蒙HarmonyOS App开发造轮子之自定义圆形图片组件的实例代码

package com.xdw.customview;

import ohos.agp.components.AttrSet;
import ohos.agp.components.Image;
import ohos.agp.render.PixelMapHolder;
import ohos.agp.utils.RectFloat;
import ohos.app.Context;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;
import ohos.media.image.ImageSource;
import ohos.media.image.PixelMap;
import ohos.media.image.common.PixelFormat;
import ohos.media.image.common.Rect;
import ohos.media.image.common.Size;

import java.io.InputStream;

/**
 * Created by 夏德旺 on 2021/1/1 11:00
 */
public class RoundImage extends Image {
 private static final HiLogLabel LABEL = new HiLogLabel(HiLog.DEBUG, 0, "RoundImage");
 private PixelMapHolder pixelMapHolder;//像素图片持有者
 private RectFloat rectDst;//目标区域
 private RectFloat rectSrc;//源区域
 public RoundImage(Context context) {
 this(context,null);

 }

 public RoundImage(Context context, AttrSet attrSet) {
 this(context,attrSet,null);
 }

 /**
 * 加载包含该控件的xml布局，会执行该构造函数
 * @param context
 * @param attrSet
 * @param styleName
 */
 public RoundImage(Context context, AttrSet attrSet, String styleName) {
 super(context, attrSet, styleName);
 HiLog.error(LABEL,"RoundImage");
 }

public void onRoundRectDraw(int radius){
 //添加绘制任务
 this.addDrawTask((view, canvas) -> {
  if (pixelMapHolder == null){
  return;
  }
  synchronized (pixelMapHolder) {
  //给目标区域赋值，宽度和高度取自xml配置文件中的属性
  rectDst = new RectFloat(0,0,getWidth(),getHeight());
  //绘制圆角图片
  canvas.drawPixelMapHolderRoundRectShape(pixelMapHolder, rectSrc, rectDst, radius, radius);
  pixelMapHolder = null;
  }
 });
 }

 //使用canvas绘制圆形
 private void onCircleDraw(){
 //添加绘制任务，自定义组件的核心api调用，该接口的参数为Component下的DrawTask接口
 this.addDrawTask((view, canvas) -> {
  if (pixelMapHolder == null){
  return;
  }
  synchronized (pixelMapHolder) {
  //给目标区域赋值，宽度和高度取自xml配置文件中的属性
  rectDst = new RectFloat(0,0,getWidth(),getHeight());
  //使用canvas绘制输出圆角矩形的位图，该方法第4个参数和第5个参数为radios参数，
  // 绘制图片，必须把图片的宽度和高度先设置成一样，然后把它们设置为图片宽度或者高度一半时则绘制的为圆形
  canvas.drawPixelMapHolderRoundRectShape(pixelMapHolder, rectSrc, rectDst, getWidth()/2, getHeight()/2);
  pixelMapHolder = null;
  }
 });
 }

/**
 *获取原有Image中的位图资源后重新检验绘制该组件
 * @param pixelMap
 */
 private void putPixelMap(PixelMap pixelMap){
 if (pixelMap != null) {
  rectSrc = new RectFloat(0, 0, pixelMap.getImageInfo().size.width, pixelMap.getImageInfo().size.height);
  pixelMapHolder = new PixelMapHolder(pixelMap);
  invalidate();//重新检验该组件
 }else{
  pixelMapHolder = null;
  setPixelMap(null);
 }
 }

 /**
 * 通过资源ID获取位图对象
 **/
 private PixelMap getPixelMap(int resId) {
 InputStream drawableInputStream = null;
 try {
  drawableInputStream = getResourceManager().getResource(resId);
  ImageSource.SourceOptions sourceOptions = new ImageSource.SourceOptions();
  sourceOptions.formatHint = "image/png";
  ImageSource imageSource = ImageSource.create(drawableInputStream, null);
  ImageSource.DecodingOptions decodingOptions = new ImageSource.DecodingOptions();
  decodingOptions.desiredSize = new Size(0, 0);
  decodingOptions.desiredRegion = new Rect(0, 0, 0, 0);
  decodingOptions.desiredPixelFormat = PixelFormat.ARGB_8888;
  PixelMap pixelMap = imageSource.createPixelmap(decodingOptions);
  return pixelMap;
 } catch (Exception e) {
  e.printStackTrace();
 } finally {
  try{
  if (drawableInputStream != null){
   drawableInputStream.close();
  }
  }catch (Exception e) {
  e.printStackTrace();
  }
 }
 return null;
 }

 /**
 * 对外调用的api，设置圆形图片方法
 * @param resId
 */
 public void setPixelMapAndCircle(int resId){
 PixelMap pixelMap = getPixelMap(resId);
 putPixelMap(pixelMap);
 onCircleDraw();
 }

 /**
 * 对外调用的api，设置圆角图片方法
 * @param resId
 * @param radius
 */
 public void setPixelMapAndRoundRect(int resId,int radius){
 PixelMap pixelMap = getPixelMap(resId);
 putPixelMap(pixelMap);
 onRoundRectDraw(radius);
 }
}