使用Canvas的drawTextOnPath方法实现沿着Path绘制文本

来源：互联网发布：des算法c语言实现编辑：程序博客网时间：2024/05/17 08:10

Android的Canvas提供了一个drawTextOnPath(String text,Path path,float hOffset,float vOffset,Paint paint)方法，该方法可以沿着Path路径绘制文本，其中text指文本内容，hOffset参数指定水平偏移、vOffset指定垂直偏移，下面用一个简单实例来演示，代码如下：

Activity：

package com.lovo.testcanvasactivity;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.os.Bundle;import android.view.View;public class TestPathActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(new MyView(this));}class MyView extends View {final String DRAW_STR = "天行健，君子以自强不息";// 画笔private Paint paint;// 声明路径对象数组Path[] paths = new Path[3];public MyView(Context context) {super(context);paths[0] = new Path();paths[0].moveTo(0, 0);for (int i = 0; i <= 7; i++) {// 生成7个点，随机生成Y坐标，并连成一条paths[0].lineTo(i * 30, (float) Math.random() * 30);}paths[1] = new Path();RectF rectF = new RectF(0, 0, 200, 120);paths[1].addOval(rectF, Path.Direction.CCW);paths[2] = new Path();paths[2].addArc(rectF, 60, 180);// 初始化画笔paint = new Paint();paint.setAntiAlias(true);paint.setColor(Color.CYAN);paint.setStrokeWidth(1);}@Overrideprotected void onDraw(Canvas canvas) {// 将背景填充为白色canvas.drawColor(Color.WHITE);canvas.translate(40, 40);// 设置从右边开始绘制（右对齐）paint.setTextAlign(Paint.Align.RIGHT);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(DRAW_STR, paths[0], -8, 20, paint);// 画布下移120canvas.translate(0, 120);// 绘制路径paint.setStyle(Paint.Style.STROKE);canvas.drawPath(paths[1], paint);// 沿着路径绘制一段文本paint.setStyle(Paint.Style.FILL);canvas.drawTextOnPath(DRAW_STR, paths[1], -20, 20, paint);// 画布下移120canvas.translate(0, 120);// 绘制路径paint.setStyle(Paint.Style.STROKE);canvas.drawPath(paths[2], paint);// 沿着路径绘制一段文本paint.setStyle(Paint.Style.FILL);canvas.drawTextOnPath(DRAW_STR, paths[2], -10, 20, paint);}}}

附上图片效果：