android自定义view实现矩形下方倒三角

效果图，内容文字可自行修改，颜色如果想自定义追加下就好。文字颜色也可以自定义属性自己在添加下就可以

package com.fawersmart.engineer.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.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;
 
import com.fawersmart.engineer.R;
 
public class RectangleWithTriangleView extends View {
    private Paint paint;
    private Paint textPaint;
    private Path path;
    private String customText;
 
    public RectangleWithTriangleView(Context context) {
        super(context);
        init(null);
    }
    public RectangleWithTriangleView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(attrs);
    }
 
    public RectangleWithTriangleView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(attrs);
    }
 
    private void init(AttributeSet attrs) {
        paint = new Paint();
        paint.setColor(Color.BLUE);
        paint.setStyle(Paint.Style.FILL);
        paint.setAntiAlias(true);
        textPaint = new Paint();
        textPaint.setColor(Color.WHITE);
        textPaint.setStyle(Paint.Style.FILL);
        textPaint.setAntiAlias(true);
        textPaint.setTextSize(28); // 文字大小，可以根据需要进行调整
 
        path = new Path();
        rectF = new RectF();
        TypedArray typedArray = getContext().obtainStyledAttributes(attrs, R.styleable.CustomView);
        customText = typedArray.getString(R.styleable.CustomView_customText);
    }
    private RectF rectF;
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
 
        int width = getWidth();
        int height = getHeight();
        int triangleHeight = width / 10; // 三角形的高度为矩形宽度的四分之一
        int cornerRadius = 10; // 圆角半径，可以根据需要进行调整
 
        // 更新圆角矩形的位置和大小
        rectF.set(0, 0, width, height - triangleHeight);
        // 绘制圆角矩形
        canvas.drawRoundRect(rectF, cornerRadius, cornerRadius, paint);
 
        // 绘制倒三角
        // 绘制倒三角形
        path.reset();
        path.moveTo(0, 5);
        path.lineTo(width, 5);
        path.lineTo(width / 2f, height);
        path.close();
 
        canvas.drawPath(path, paint);
        // 绘制文字
        float textWidth = textPaint.measureText(customText);
        float x = rectF.centerX() - textWidth / 2;
        float y = rectF.centerY() - (textPaint.descent() + textPaint.ascent()) / 2;
        canvas.drawText(customText, x, y, textPaint);
 
 
    }
 
    private float dpToPx(float dp) {
        return dp * getResources().getDisplayMetrics().density;
    }
}

在res/values/attrs.xml文件中定义自定义属性：

<resources>
    <declare-styleable name="CustomView">
        <attr name="customText" format="string" />
        <attr name="customTextColor" format="color" />
    </declare-styleable>
</resources>

引用

     <com.fawersmart.engineer.View.RectangleWithTriangleView
                    android:layout_width="36dp"
                    android:layout_marginLeft="2dp"
 
                    app:customText="text!"
                    android:layout_height="18dp"/>