Android实现IM多人员组合的群组头像

说明：

此头像类似微信群组头像，整个头像由组内前N位人员的头像组合而成，可用网络或本地图片进行组合，最终显示为一个头像整体，看效果图：

一、自定义整体头像的ViewGroup，计算并保存宽高(重写onMeasure)：

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 mWidth = getWidth(widthMeasureSpec);
 mHeight = getHeight(heightMeasureSpec);
 setMeasuredDimension(mWidth, mHeight);
}

private int getWidth(int measureSpec) {
 int width = MIN_WIDTH_AND_HEIGHT;
 int specMode = MeasureSpec.getMode(measureSpec);
 int specSize = MeasureSpec.getSize(measureSpec);
 if (specMode == MeasureSpec.EXACTLY) {
  width = specSize;
 } else if (specMode == MeasureSpec.AT_MOST) {
  width = Math.min(MIN_WIDTH_AND_HEIGHT, specSize);
 }
 return width;
}

private int getHeight(int measureSpec) {
 int height = MIN_WIDTH_AND_HEIGHT;
 int specMode = MeasureSpec.getMode(measureSpec);
 int specSize = MeasureSpec.getSize(measureSpec);
 if (specMode == MeasureSpec.EXACTLY) {
  height = specSize;
 } else if (specMode == MeasureSpec.AT_MOST) {
  height = Math.min(MIN_WIDTH_AND_HEIGHT, specSize);
 }
 return height;
}

二、布局子头像的View(重写onLayout，对每个子头像进行布局)：

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
 layoutChild();
}

private void layoutChild() {
 if (mImgUrls == null || mImgUrls.isEmpty()) {
  return;
 }
 for (int i = 0; i < mImgSize; i++) {
  ImageView itemV = (ImageView) getChildAt(i);
  int left = 0, top = 0, right = 0, bottom = 0;
  /*
  对每个item的View计算left、top、right、bottom四个值
   */
  ...
  itemV.layout(left, top, right, bottom); //真正布局子头像位置
  showImage(itemV, mImgUrls.get(i)); //加载并显示子头像图片
 }
}

三、加载并显示各子头像(使用Glide加载并显示每个子头像)

private void showImage(Context context, ImageView iv, String url) {
 if (TextUtils.isEmpty(url)) {
  Bitmap bmp = BitmapFactory.decodeResource(context.getResources(), R.mipmap.user_default_icon);
  iv.setImageBitmap(bmp);
  return;
 }
 Glide.with(context).load(url)
   .diskCacheStrategy(DiskCacheStrategy.ALL)
   .dontAnimate()
   .placeholder(R.mipmap.user_default_icon)
   .error(R.mipmap.user_default_icon)
   .into(iv);
}

到此多图片组合头像已经完成，不过想要圈形的还需要进行以下步奏

四、裁剪整个群头像为圆形(重写dispatchDraw)：

@Override
protected void dispatchDraw(Canvas canvas) {
 Path path = new Path();
 path.addCircle(mWidth / 2, mHeight / 2, mWidth / 2, Path.Direction.CW);
 canvas.clipPath(path);
 canvas.drawColor(Color.TRANSPARENT);
 super.dispatchDraw(canvas);
 drawGroupView(canvas);
}

/**
 * 绘制各头像间隔线
 * @param canvas
 */
private void drawGroupView(Canvas canvas) {
 /*
 计算各条线的x和y坐标值
  */
 float[] point1 = new float[2], point2 = new float[2];
 ...
 drawLine(canvas, point1, point2);
}

/**
 * 绘制直线
 */
private void drawLine(Canvas canvas, float[] point1, float[] point2) {
 mPaint.reset();
 mPaint.setAntiAlias(true);
 mPaint.setStrokeWidth(mInterval);
 mPaint.setColor(Color.WHITE);
 mPaint.setStyle(Paint.Style.STROKE);
 canvas.drawLine(point1[0], point1[1], point2[0], point2[1], mPaint);
}

五、暴露公共方法供外部调用：

/**
 * 设置图片url集合
 *
 * @param imgs 图片url集合
 */
public void setImages(List<String> imgs) {
 if (imgs == null || imgs.isEmpty()) {
  return;
 }
 if (imgs.size() > MAX_SIZE) {
  imgs = imgs.subList(0, MAX_SIZE);
 }
 removeAllViews();
 mImgUrls = imgs;
 mImgSize = imgs.size();
 for (int i = 0; i < mImgSize; i++) {
  View v = getItemView(i);
  if (v == null) {
   return;
  }
  addView(v, generateDefaultLayoutParams());
 }
 requestLayout();
}

/**
 * 设置单个图片url
 *
 * @param img 图片url
 */
public void setImageUrl(String img) {
 ArrayList imgUrls = new ArrayList<>();
 imgUrls.add(img);
 setImages(imgUrls);
}

/**
 * 生成一个头像布局
 */
private ImageView getItemView(int position) {
 ...
}

六、使用：

1.写一个布局文件放自定义群组头像控件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:background="#f2f2f2"
   android:orientation="vertical">

<com.yyh.im.ui.widget.HeadView
 android:id="@+id/cv_head"
 android:layout_width="150dp"
 android:layout_height="150dp"/>

</LinearLayout>

2.代码中群组头像控件显示图片：

@BindView(R2.id.cv_head)
public HeadView mHeadCv;

private String[] IMG_URL_LIST = {
  "70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=416954025,2289731303&fm=27&gp=0.jpg",
  "70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=704997830,3098922597&fm=27&gp=0.jpg",
  "70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=1375449509,557259337&fm=27&gp=0.jpg",
  "70cFvnSh_Q1YnxGkpoWK1HF6hhy/it/u=2825392570,1862752263&fm=27&gp=0.jpg",
  "70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=3252489351,440833245&fm=27&gp=0.jpg",
  "70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=3586311245,3082636880&fm=27&gp=0.jpg"
};

private void showImage(){
 ArrayList<String> list = new ArrayList<>();
 for (int i = 0; i < 6; i++) {
  list.add(IMG_URL_LIST[i]);
 }
 mHeadCv.setImageUrls(list);
}

来源：https://blog.csdn.net/a526001650a/article/details/78814570