Android沿路径绘制文本

Android的Canvas还提供了一个

drawTextOnPath(String text，Path path，float hOffset，float vOffset，Paint paint)

该方法沿着Path绘制文本，hOffset参数指定水平偏移，vOffset参数指定垂直偏移



MainActivity.java

package com.example.drawpathtext;

import android.os.Bundle;

import android.app.Activity;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Path;

import android.graphics.RectF;

import android.view.Menu;

import android.view.View;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new MyTextView(MainActivity.this));
}

class MyTextView extends View{

Path[] paths=new Path[3];
Paint paint;

public MyTextView(Context context) {
super(context);
paths[0]=new Path();
paths[0].moveTo(0, 0);
for(int i=1;i<=7;i++){
//生成7个点，随机生成他们的Y坐标，并将他们连成一条线
paths[0].lineTo(i*30, (float) (Math.random()*30));
}

paths[1]=new Path();
RectF rectF=new RectF(0,0,200,120);
//向路径中添加椭圆
paths[1].addOval(rectF, Path.Direction.CCW);

paths[2]=new Path();
//向路径中添加椭圆弧,60代表开始角度，180代表弧线扫描过的角度
paths[2].addArc(rectF, 60, 180);

//初始化画笔
paint=new Paint();
paint.setAntiAlias(true);
paint.setColor(Color.GRAY);
paint.setStrokeWidth(2);

}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.WHITE);
canvas.translate(40, 40);

//设置从右边开始绘制
paint.setTextAlign(Paint.Align.LEFT);
paint.setTextSize(20);

//绘制路径
paint.setStyle(Paint.Style.STROKE);
canvas.drawPath(paths[0], paint);

//沿着路径绘制一段文本
paint.setStyle(Paint.Style.FILL);
canvas.drawTextOnPath("安卓手机开发", paths[0], 0, 10, paint);

canvas.translate(0, 60);
//绘制路径
paint.setStyle(Paint.Style.STROKE);
canvas.drawPath(paths[1], paint);
paint.setStyle(Paint.Style.FILL);
canvas.drawTextOnPath("安卓手机开发", paths[1], 0, 10, paint);

canvas.translate(0, 120);
//绘制路径
paint.setStyle(Paint.Style.STROKE);
canvas.drawPath(paths[2], paint);
paint.setStyle(Paint.Style.FILL);
canvas.drawTextOnPath("安卓手机开发", paths[2], 5, 5, paint);
}

}

}