我正在写一个线程的画布.
public void draw(Canvas canvas) {
Paint p = new Paint();
p.setAntiAlias(true);
p.setTextSize(30);
p.setColor(Color.WHITE);
p.setTextAlign(Paint.Align.CENTER);
canvas.drawText("Centered",xCentre,yCentre,p);
}
当我有一个多色的SpannableStringBuilder我想写入画布时我的问题就开始了,我不知道怎么做. SpannableStringBuilder有一个drawText()方法,我一直无法使用.或者是否有其他方法将字符串写入画布,其中一些字母具有不同的颜色？
解决方法
我自己找到了解决方案.
您可以计算字符串在画布上绘制后的宽度.然后你知道在改变颜色之后还在哪里继续向画布绘制文本.
package com.example;
import android.app.Activity;
import android.content.Context;
import android.graphics.*;
import android.os.Bundle;
import android.view.View;
public class MyActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}
private static class SampleView extends View {
public SampleView(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
String blackText = "black";
String redText = " red";
Paint mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setTextSize(30);
mPaint.setTypeface(Typeface.create(Typeface.SERIF,Typeface.ITALIC));
float canvasWidth = canvas.getWidth();
float blackTextWidth = mPaint.measureText(blackText);
float sentenceWidth = mPaint.measureText(blackText + redText);
float startPositionX = (canvasWidth - sentenceWidth) / 2;
mPaint.setTextAlign(Paint.Align.LEFT);
canvas.translate(0,80);
mPaint.setColor(Color.BLACK);
canvas.drawText(blackText,startPositionX,mPaint);
mPaint.setColor(Color.RED);
canvas.drawText(redText,startPositionX + blackTextWidth,mPaint);
}
}
}
