CornerViewLayout & CornerView（标签）

右下角角标文本，斜体文本，标签文本，使用CornerViewLayout作为父布局，则在该父布局右下角绘制三角形角标以及旋转的文本，或单独使用CornerView作为一个子控件，放置在某个布局右下角实现三角形角标和旋转文本
2017-7-26更新
为使角标绘制在顶层，调整至dispatchDraw方法中绘制；同时调整了一下字号，当字体个数小于3时字体减小5，如果不减小的话有点偏大不大好看。

调整前效果图

调整后效果图

可自定义角标大小，文本大小自适应
xml

CornerViewLayout.java

package com.forens.xuan.forkit.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.support.annotation.AttrRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.widget.FrameLayout;

import com.forens.xuan.forkit.R;


/**
 * Project_Name:
 * Copyright:
 * Created:         dake.xuan on 2017/7/25 11:47
 * E-mail:          [email protected]
 * Desc:            (说明描述)
 */

public class CornerViewLayout extends FrameLayout{
    private String cornerContent;
    private int cornerColor;
    private float cornerSize;

    public CornerViewLayout(@NonNull Context context) {
        super(context);
    }

    public CornerViewLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        initCornerViewLayout(context,attrs);
    }

    public CornerViewLayout(@NonNull Context context, @Nullable AttributeSet attrs, @AttrRes int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initCornerViewLayout(context,attrs);
    }
    private void initCornerViewLayout(Context context,AttributeSet attrs){

        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CornerView);
        cornerContent=a.getString(R.styleable.CornerView_cornerText);
        cornerColor=a.getColor(R.styleable.CornerView_cornerColor, Color.parseColor("#a4a4a4"));
        cornerSize=a.getDimensionPixelSize(R.styleable.CornerView_cornerSize,50);
        a.recycle();
        setWillNotDraw(false);
    }
     @Override
    protected void dispatchDraw(Canvas canvas) {
        super.dispatchDraw(canvas);
        if(cornerContent==null)return;
        int height=getHeight();
        if(height

CornerView.java

package com.forens.xuan.forkit.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

import com.forens.xuan.forkit.R;


/**
 * Project_Name:
 * Copyright:
 * Created:         dake.xuan on 2017/7/25 14:17
 * E-mail:          [email protected]
 * Desc:            (说明描述)
 */

public class CornerView extends View{
    private String cornerContent;
    private int cornerColor;
    public CornerView(Context context) {
        super(context);
    }

    public CornerView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        initCornerView(context,attrs);
    }

    public CornerView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initCornerView(context,attrs);
    }
    private void initCornerView(Context context,AttributeSet attrs){
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CornerView);
        cornerContent=a.getString(R.styleable.CornerView_cornerText);
        cornerColor=a.getColor(R.styleable.CornerView_cornerColor, Color.parseColor("#a4a4a4"));
        a.recycle();
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        //以宽度限定宽高
        super.onMeasure(widthMeasureSpec, widthMeasureSpec);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if(cornerContent==null)return;
        //先填充右下角三角形颜色
        Path path1=new Path();
        path1.moveTo(getWidth(),0);
        path1.lineTo(0,getHeight());
        path1.lineTo(getWidth(),getHeight());
        Paint paint1=new Paint();
        paint1.setColor(cornerColor);
        canvas.drawPath(path1,paint1);


        Paint textPaint=new Paint();
        textPaint.setTextAlign(Paint.Align.CENTER);
        textPaint.setStyle(Paint.Style.FILL);
        textPaint.setAntiAlias(true);
        textPaint.setColor(Color.WHITE);
        double m=(Math.sqrt(2)*getHeight())/2;
        float size= (float) (m/cornerContent.length());//根据实际路径长度求得字体大小
        textPaint.setTextSize(size);
        //沿路径绘制文本
        Path path=new Path();
        path.moveTo(getHeight()/2,getHeight());
        path.lineTo(getHeight(),getHeight()/2);
        canvas.drawTextOnPath(cornerContent,path,0, 0,textPaint);
    }
}

styleable