Android使用StaticLayout实现文本绘制自动换行

使用的场景主要是绘制文本的时候指定绘制区域的宽度，文本需要根据宽度自动换行。

使用TextPaint和StaticLayout就可以实现这个功能，并可以获得绘制后的文本区域的高度：

 

package com.hu.text;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.view.MotionEvent;
import android.view.View;

import com.example.texttest.R;

public class MyView extends View {
	
	TextPaint textPaint = null;
	StaticLayout staticLayout = null;
	Paint paint = null;
	int width = 50;
	int height = 0;
	String txt = null;
	boolean running = false;

	public MyView(Context context) {
		super(context);
		textPaint = new TextPaint();
		textPaint.setAntiAlias(true);
		textPaint.setTextSize(12);
		txt = getResources().getString(R.string.my_text);
		staticLayout = new StaticLayout(txt, textPaint, width, Alignment.ALIGN_NORMAL, 1, 0, false);
		height = staticLayout.getHeight();
		paint = new Paint();
		paint.setStyle(Style.STROKE);
		paint.setColor(Color.RED);
	}
	
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub
		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			running = !running;
			if(running){
				new Thread(){
					public void run() {
						while(running){
							width ++;
							staticLayout = new StaticLayout(txt, textPaint, width, Alignment.ALIGN_NORMAL, 1, 0, false);
							height = staticLayout.getHeight();
							postInvalidate();
							try {
								Thread.sleep(50);
							} catch (InterruptedException e) {
								// TODO Auto-generated catch block
								e.printStackTrace();
							}
							if(width >= 300){
								width = 50;
							}
						}
					};
				}.start();
			}
			break;
		default:
			break;
		}
		return super.onTouchEvent(event);
	}

	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
		canvas.translate(20, 20);
		staticLayout.draw(canvas);
		canvas.drawRect(0, 0, width, height, paint);
		super.onDraw(canvas);
	}

}

 

 完。