绘制字符串：

字符串工具类：
/**
* 实现文字自动换行
* 自动翻页
*/
package com.yarin.android.Examples_05_06;

import java.util.Vector;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.FontMetrics;
import android.view.KeyEvent;

public class TextUtil
{
int m_iTextPosX; //绘制的x点
int m_iTextPosY; //绘制的y点
int m_iTextWidth; //绘制宽度
int m_iTextHeight; //绘制高度

int m_iFontHeight; //字体高度

int m_ipageLineNum; //每一页显示的行数

int m_iTextBGColor; // 背景颜色
int m_iTextColor; // 字体颜色
int m_iAlpha; //Alpha值

int m_iRealLine; // 字符串真实的行数
int m_iCurLine; //当前行

String m_strText;

Vector m_String;

Paint m_paint;

int m_iTextSize;

public TextUtil()
{
m_paint = new Paint();
m_String = new Vector();
}

public TextUtil(String strText, int x, int y, int w, int h, int bgcolor, int txetcolor, int a, int iTextSize)
{
m_paint = new Paint();
m_String = new Vector();

m_strText = strText;

m_iTextPosX = x;
m_iTextPosY = y;
m_iTextWidth = w;
m_iTextHeight = h;

m_iTextBGColor = bgcolor;
m_iTextColor = txetcolor;

m_iTextSize = iTextSize;

m_iAlpha = a;

}

/**
* 初始化
* @param strText 要显示的字符串
* @param x x
* @param y y
* @param w w
* @param h h
* @param bgcolor 背景颜色
* @param txetcolor 文字的颜色
* @param a Alpha
* @param iTextSize 字体大小
*/
public void InitText(String strText, int x, int y, int w, int h, int bgcolor, int txetcolor, int a, int iTextSize)
{
m_iCurLine = 0;
m_ipageLineNum = 0;
m_iRealLine = 0;
m_strText = "";
m_iTextPosX = 0;
m_iTextPosY = 0;
m_iTextWidth = 0;
m_iTextHeight = 0;
m_iTextBGColor = 0;
m_iTextColor = 0;
m_iTextSize = 0;
m_iAlpha = 0;

m_String.clear();

SetText(strText);
SetRect(x, y, w, h);
SetBGColor(bgcolor);
SetTextColor(txetcolor);
SetFontSize(iTextSize);
SetAlpha(a);

SetPaint();

GetTextIfon();
}

/**
* 设置Alpha
* @param a Alpha值
*/
public void SetAlpha(int a)
{
m_iAlpha = a;
}

/**
* 对Paint属性的设置
*/
public void SetPaint()
{
m_paint.setARGB(m_iAlpha, Color.red(m_iTextColor), Color.green(m_iTextColor), Color.blue(m_iTextColor));
m_paint.setTextSize(m_iTextSize);
}

/**
* 设置字体尺寸
* @param iTextSize
*/
public void SetFontSize(int iTextSize)
{
m_iTextSize = iTextSize;
}

/**
* 设置显示文本的区域
* @param x
* @param y
* @param w
* @param h
*/
public void SetRect(int x, int y, int w, int h)
{
m_iTextPosX = x;
m_iTextPosY = y;
m_iTextWidth = w;
m_iTextHeight = h;
}

/**
* 设置背景颜色
* @param bgcolor
*/
public void SetBGColor(int bgcolor)
{
m_iTextBGColor = bgcolor;
}

/**
* 设置字体颜色
* @param txetcolor
*/
public void SetTextColor(int txetcolor)
{
m_iTextColor = txetcolor;
}

/**
* 色绘制要显示的字符串
* @param strText
*/
public void SetText(String strText)
{
m_strText = strText;
}

/**
* 得到字符串的信息
* 包括：行数、页数等信息
* 内部调用
*/
public void GetTextIfon()
{
char ch;
int w = 0;
int istart = 0;
FontMetrics fm = m_paint.getFontMetrics();

m_iFontHeight = (int) Math.ceil(fm.descent - fm.top) + 2;

m_ipageLineNum = m_iTextHeight / m_iFontHeight;

for (int i = 0; i < m_strText.length(); i++)
{
ch = m_strText.charAt(i);
float[] widths = new float[1];
String srt = String.valueOf(ch);
m_paint.getTextWidths(srt, widths);

if (ch == '\n')
{
m_iRealLine++;
m_String.addElement(m_strText.substring(istart, i));
istart = i + 1;
w = 0;
}
else
{
w += (int) (Math.ceil(widths[0]));
if (w > m_iTextWidth)
{
m_iRealLine++;
m_String.addElement(m_strText.substring(istart, i));
istart = i;
i--;
w = 0;
}
else
{
if (i == (m_strText.length() - 1))
{
m_iRealLine++;
m_String.addElement(m_strText.substring(istart, m_strText.length()));
}
}
}
}
}

/**
* 绘制字符串
* @param canvas
*/
public void DrawText(Canvas canvas)
{
for (int i = m_iCurLine, j = 0; i < m_iRealLine; i++, j++)
{
if (j > m_ipageLineNum)
{
break;
}
canvas.drawText((String) (m_String.elementAt(i)), m_iTextPosX, m_iTextPosY + m_iFontHeight * j, m_paint);
}
}

/**
* 翻页等按键处理
* @param keyCode
* @param event
* @return
*/
public boolean KeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_DPAD_UP)
{
if (m_iCurLine > 0)
{
m_iCurLine--;
}
}
else if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN)
{
if ((m_iCurLine + m_ipageLineNum) < (m_iRealLine - 1))
{
m_iCurLine++;
}
}
return false;
}
}
视图类：
package com.yarin.android.Examples_05_06;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;

public class GameView extends View implements Runnable
{
/* 声明Paint对象 */
private Paint mPaint = null;
private int mICount = 0;

/* 声明TextUtil对象 */
private TextUtil mTextUtil = null;
public GameView(Context context)
{
super(context);
/* 构建对象 */
mPaint = new Paint();

String string = "测试自动换行\n\n设置文字自动换行abcdefgh\niklmnopqrst换行123347465\n43756245Android\n设置文字自动换行abcdefgh\niklmnopqrst换行123347465\n43756245Android";

/* 实例化TextUtil */
mTextUtil = new TextUtil(string,5,50,300,80,0x0,0xffffff,255,16);

/* 初始化TextUtil */
mTextUtil.InitText(string,5,50,300,80,0x0,0xffffff,255,16);

/* 开启线程 */
new Thread(this).start();
}

public void onDraw(Canvas canvas)
{
super.onDraw(canvas);

/* 设置背景颜色 */
canvas.drawColor(Color.BLACK);

mPaint.setAntiAlias(true);

if ( mICount < 100 )
{
mICount++;
}

mPaint.setColor(Color.RED);

canvas.drawText("装在进度："+mICount+"%......", 10, 20, mPaint);

/* 绘制TextUtil：实现自动换行 */
mTextUtil.DrawText(canvas);
}

// 触笔事件
public boolean onTouchEvent(MotionEvent event)
{
return true;
}

// 按键按下事件
public boolean onKeyDown(int keyCode, KeyEvent event)
{
return mTextUtil.KeyDown(keyCode, event);
}

// 按键弹起事件
public boolean onKeyUp(int keyCode, KeyEvent event)
{
return false;
}

public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event)
{
return true;
}

/**
* 线程处理
*/
public void run()
{
while (!Thread.currentThread().isInterrupted())
{
try
{
Thread.sleep(100);
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
}
//使用postInvalidate可以直接在线程中更新界面
postInvalidate();
}
}
}