在自定义的圆里中间写入文字

朱雀 2022-07-14 03:22 126阅读 0赞

package com.example.kirito.animation360_1.view;
    
    import android.content.Context;
    import android.graphics.Canvas;
    import android.graphics.Color;
    import android.graphics.Paint;
    import android.util.AttributeSet;
    import android.util.Log;
    import android.view.View;
    
    /** * Created by kirito on 2016.11.24. */
    
    public class FloatCircleView extends View { 
        public int width = 150;
        public int height = 150;
        private Paint circlePaint;
        private Paint textPaint;
    
    
        private static final String TAG = "FloatCircleView";
    
        //三个构造函数都必须调用，否则无法正常使用自定义view
        public FloatCircleView(Context context) {
            this(context,null);
        }
    
        public FloatCircleView(Context context, AttributeSet attrs) {
            this(context, attrs,0);
        }
    
        public FloatCircleView(Context context, AttributeSet attrs, int defStyleAttr) {
            super(context, attrs, defStyleAttr);
            initPaint();
        }
    
        public void initPaint(){
            circlePaint = new Paint();
            circlePaint.setAntiAlias(true);
            circlePaint.setColor(Color.BLUE);
    
            textPaint = new Paint();
            textPaint.setAntiAlias(true);
            textPaint.setTextSize(25);
            textPaint.setColor(Color.RED);
            textPaint.setFakeBoldText(true);
        }
    
        @Override
        protected void onDraw(Canvas canvas) {
            canvas.drawCircle(width / 2,width / 2,width / 2,circlePaint);
    
            String text = "50%";
            float textWidth = textPaint.measureText(text);
            float x = (width - textWidth) / 2;
            Paint.FontMetrics metrics = textPaint.getFontMetrics();
            //ascent是负的，descent是正的，dy是正的
            float dy = -(metrics.ascent + metrics.descent) / 2;
            float y = height / 2 + dy;
    
            canvas.drawText(text,x,y,textPaint);
        }
    
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            setMeasuredDimension(width,height);
        }
    }

![实现效果][20161125143857831]

[20161125143857831]: /images/20220714/e1a1f42661cd42cb98910b46d3ec43cf.png