Android实现左上角（其他边角）倾斜的标签（环绕效果）效果

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.constraintlayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:background="#fff"
  android:layout_height="match_parent"
  tools:context=".mainactivity">
  <relativelayout
    android:layout_width="300dp"
    android:layout_height="200dp"
    android:background="#fff"
    app:layout_constraintbottom_tobottomof="parent"
    app:layout_constraintleft_toleftof="parent"
    app:layout_constraintright_torightof="parent"
    app:layout_constrainttop_totopof="parent" >
    <relativelayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_margin="5dp"
      android:background="#33b7f3"
      android:elevation="2dp"></relativelayout>
    <com.zc.labeldemo.labelview
      android:id="@+id/labelview"
      android:layout_alignparenttop="true"
      android:layout_width="75dp"
      android:elevation="3dp"
      android:layout_height="75dp"/>
  </relativelayout>
</androidx.constraintlayout.widget.constraintlayout>

package com.zc.labeldemo;
import android.content.context;
import android.graphics.canvas;
import android.graphics.color;
import android.graphics.paint;
import android.graphics.path;
import android.util.attributeset;
import android.view.view;
import androidx.annotation.nullable;
/**
 * @author wenchao
 * @version 1.0.1
 * @classname labelview
 * @date 2019/9/20
 * @description
 */
public class labelview extends view {
  /**
   * 画笔
   */
  private paint paint;
  /**
   * path
   */
  private path path;
  /**
   * view宽度
   */
  private float width;
  /**
   * view高度
   */
  private float height;
  /**
   * 标签背景宽度
   */
  private float labelwidth;
  /**
   * 标签折叠区域宽度
   */
  private float pointwidth;
  /**
   * 标签折叠区域高度
   */
  private float pointheight;
  /**
   * 标签背景颜色
   */
  private int labelcolor;
  /**
   * 标签折叠区域背景颜色
   */
  private int pointcolor;
  /**
   * 中心点x坐标
   */
  private float centerx;
  /**
   * 中心点y坐标
   */
  private float centery;
  /**
   * 标签文字内容
   */
  private string text;
  /**
   * 标签文字颜色
   */
  private int textcolor;
  public labelview(context context) {
    super(context);
  }
  public labelview(context context, @nullable attributeset attrs) {
    super(context, attrs);
    init();
  }
  private void init() {
    labelwidth = 120;
    pointwidth = 10;
    pointheight = 17;
    paint = new paint();
    path = new path();
    paint.setantialias(true);
    paint.setstrokewidth(10);
    setbackgroundcolor(color.transparent);
    labelcolor = color.parsecolor("#ea6724");
    pointcolor = color.parsecolor("#c43200");
    text = "测试内容";
    textcolor = color.white;
  }
  @override
  protected void onsizechanged(int w, int h, int oldw, int oldh) {
    super.onsizechanged(w, h, oldw, oldh);
    width = w;
    height = h;
    centerx = w/2;
    centery = h/2;
  }
  @override
  public void draw(canvas canvas) {
    super.draw(canvas);
    //画标签区域背景上边的折叠区域（小三角区域）
    path.reset();
    path.moveto(width-pointwidth,0);
    path.lineto(width,pointheight);
    path.lineto(width-pointwidth-26,pointheight);
    path.close();
    paint.setcolor(pointcolor);
    canvas.drawpath(path,paint);
    //画标签背景区域下边的折叠区域
    path.reset();
    path.moveto(0,height-pointwidth);
    path.lineto(pointheight,height);
    path.lineto(pointheight,height-pointwidth-26);
    path.close();
    paint.setcolor(pointcolor);
    canvas.drawpath(path,paint);
    //画标签背景区域
    path.reset();
    paint.setcolor(labelcolor);
    paint.setstyle(paint.style.fill);
    path.moveto(width-labelwidth-pointwidth,0);
    path.lineto(width-pointwidth,0);
    path.lineto(0,height-pointwidth);
    path.lineto(0,height-labelwidth-pointwidth);
    canvas.drawpath(path,paint);
    //画文字 逆时针选择45度
    canvas.rotate(-45,centerx,centery);
    //文字中心点横坐标
    float textx = width / 2;
    //文字中心点纵坐标
    float texty = (height-pointwidth-(labelwidth / 2f)) / 2f;
    paint.setcolor(textcolor);
    paint.setstyle(paint.style.fill);
    paint.settextsize(38);
    //设置文字居中绘制
    paint.settextalign(paint.align.center);
    canvas.drawtext(text,textx,texty,paint);
  }
}