<declare-styleable name="VerifyCode">
 <attr name="codeTextSize" format="dimension"/>
 <attr name="codeBackground" format="color"/>
 <attr name="codeLength" format="integer"/>
 <attr name="isContainChar" format="boolean"/>
 <attr name="pointNum" format="integer"/>
 <attr name="linNum" format="integer"/>
 </declare-styleable>

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;
import java.util.Random;
/**
 * 類描述:自定義驗證碼
 * 創(chuàng)建者：lb
 */
public class VerifyCode extends View {
 private String mCodeText;//文本內容
 private int mCodeTextSize;//文本大小
 private int mCodeLength;//驗證碼長度
 private int mCodeBackground;//背景色
 private boolean isContainChar;//驗證碼是否包含字母
 private int mPointNum;//干擾點數
 private int mLineNum;//干擾線數
 private Paint mPaint;//畫筆
 private Rect mBound;//繪制范圍
 private Bitmap bitmap;//驗證碼圖片
 private static Random mRandom = new Random();
 private static int mWidth;//控件的寬度
 private static int mHeight;//控件的高度
 public VerifyCode(Context context) {
 super(context);
 }
 public VerifyCode(Context context, AttributeSet attrs) {
 super(context, attrs);
 initAttrValues(context,attrs);
 initData();
 }
 /**
 * 初始化屬性集合
 * @param context
 * @param attrs
 */
 private void initAttrValues(Context context, AttributeSet attrs){
 // //獲取在AttributeSet中定義的 VerifyCode 中聲明的屬性的集合
 TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.VerifyCode);
 //獲取TypeArray的長度
 int count=typedArray.getIndexCount();
 for (int i=0;i<count;i++){
  //獲取此項屬性的ID
  int index=typedArray.getIndex(i);
  switch (index){
  case R.styleable.VerifyCode_codeTextSize:
   // 默認設置為16sp，TypeValue類 px轉sp 一個轉換類
   mCodeTextSize =typedArray.getDimensionPixelSize(index,(int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));
   break;
  case R.styleable.VerifyCode_codeBackground:
mCodeBackground=typedArray.getColor(index,Color.WHITE);
   break;
  case R.styleable.VerifyCode_codeLength:
   mCodeLength=typedArray.getInteger(index,4);
   break;
  case R.styleable.VerifyCode_isContainChar:
   isContainChar=typedArray.getBoolean(index,false);
   break;
  case R.styleable.VerifyCode_pointNum:
   mPointNum=typedArray.getInteger(index,100);
   break;
  case R.styleable.VerifyCode_linNum:
   mLineNum=typedArray.getInteger(index,3);
   break;
  }
 }
 //Recycles the TypedArray, to be re-used by a later caller
 //官方解釋：回收TypedArray 以便后面的使用者重用
 typedArray.recycle();
 }
 /**
 * 初始化數據
 */
 private void initData(){
 mCodeText=getValidationCode(mCodeLength,isContainChar);
 mPaint=new Paint();
 mPaint.setAntiAlias(true);
 mBound=new Rect();
 //計算文字所在矩形，可以得到寬高
 mPaint.getTextBounds(mCodeText,0, mCodeText.length(),mBound);
 }
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 //獲取控件寬高的顯示模式
 int widthMode=MeasureSpec.getMode(widthMeasureSpec);
 int heightMode=MeasureSpec.getMode(heightMeasureSpec);
 //獲取寬高的尺寸值 固定值的寬度
 int widthSize=MeasureSpec.getSize(widthMeasureSpec);
 int heightSize=MeasureSpec.getSize(heightMeasureSpec);
 //設置寬高默認為建議的最小寬高
 int width= getDefaultSize(getSuggestedMinimumWidth(),widthMeasureSpec) ;
 int height=getDefaultSize(getSuggestedMinimumHeight(),heightMeasureSpec);

// MeasureSpec父布局傳遞給后代的布局要求 包含 確定大小和三種模式
// EXACTLY：一般是設置了明確的值或者是MATCH_PARENT
// AT_MOST：表示子布局限制在一個最大值內，一般為WARP_CONTENT
// UNSPECIFIED：表示子布局想要多大就多大，很少使用
 if (widthMode==MeasureSpec.EXACTLY){
  width=widthSize;
 }else{
  mPaint.setTextSize(mCodeTextSize);
  mPaint.getTextBounds(mCodeText,0,mCodeText.length(),mBound);
  float textWidth=mBound.width();
  int tempWidth=(int)(getPaddingLeft()+textWidth+getPaddingRight());
  width=tempWidth;
 }
 if (heightMode == MeasureSpec.EXACTLY)
 {
  height = heightSize;
 } else
 {
  mPaint.setTextSize(mCodeTextSize);
  mPaint.getTextBounds(mCodeText, 0, mCodeText.length(), mBound);
  float textHeight = mBound.height();
  int tempHeight = (int) (getPaddingTop() + textHeight + getPaddingBottom());
  height = tempHeight;
 }
 //設置測量的寬高
 setMeasuredDimension(width,height);
 }
 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 mWidth=getWidth();
 mHeight=getHeight();

 if (bitmap==null){
  bitmap=createBitmapValidate();
 }
 canvas.drawBitmap(bitmap,0,0,mPaint);
 }
 @Override
 public boolean onTouchEvent(MotionEvent event) {
 switch (event.getAction()){
  case MotionEvent.ACTION_DOWN:
  refresh();
  break;
 }
 return super.onTouchEvent(event);
 }
 /**
 * 創(chuàng)建圖片驗證碼
 * @return
 */
 private Bitmap createBitmapValidate(){
 if(bitmap != null && !bitmap.isRecycled()){
  //回收并且置為null
  bitmap.recycle();
  bitmap = null;
 }
 //創(chuàng)建圖片
 Bitmap sourceBitmap=Bitmap.createBitmap(mWidth,mHeight, Bitmap.Config.ARGB_8888);
 //創(chuàng)建畫布
 Canvas canvas=new Canvas(sourceBitmap);
 //畫上背景顏色
 canvas.drawColor(mCodeBackground);
 //初始化文字畫筆
 mPaint.setStrokeWidth(3f);
 mPaint.setTextSize(mCodeTextSize);
 //測量驗證碼字符串顯示的寬度值
 float textWidth=mPaint.measureText(mCodeText);
 //畫上驗證碼
 int length = mCodeText.length();
 //計算一個字符的所占位置
 float charLength = textWidth / length;
 for (int i = 1; i <= length; i++) {
  int offsetDegree = mRandom.nextInt(15);
  //這里只會產生0和1，如果是1那么正旋轉正角度，否則旋轉負角度
  offsetDegree = mRandom.nextInt(2) == 1 ? offsetDegree : -offsetDegree;
  //用來保存Canvas的狀態(tài)。save之后，可以調用Canvas的平移、放縮、旋轉、錯切、裁剪等操作。
  canvas.save();
  //設置旋轉
  canvas.rotate(offsetDegree, mWidth / 2, mHeight / 2);
  //給畫筆設置隨機顏色
  mPaint.setARGB(255, mRandom.nextInt(200) + 20, mRandom.nextInt(200) + 20,
   mRandom.nextInt(200) + 20);
  //設置字體的繪制位置
  canvas.drawText(String.valueOf(mCodeText.charAt(i - 1)), (i - 1) * charLength+5,
   mHeight * 4 / 5f, mPaint);
  //用來恢復Canvas之前保存的狀態(tài)。防止save后對Canvas執(zhí)行的操作對后續(xù)的繪制有影響。
  canvas.restore();
 }
 //重新設置畫筆
 mPaint.setARGB(255, mRandom.nextInt(200) + 20, mRandom.nextInt(200) + 20,
  mRandom.nextInt(200) + 20);
 mPaint.setStrokeWidth(1);
 //產生干擾效果1 －－ 干擾點
 for (int i = 0; i < mPointNum; i++) {
  drawPoint(canvas, mPaint);
 }
 //生成干擾效果2 －－ 干擾線
 for (int i = 0; i < mLineNum; i++) {
  drawLine(canvas, mPaint);
 }
 return sourceBitmap;
 }
 /**
 * 生成干擾點
 */
 private static void drawPoint(Canvas canvas, Paint paint) {
 PointF pointF = new PointF(mRandom.nextInt(mWidth) + 10, mRandom.nextInt(mHeight) + 10);
 canvas.drawPoint(pointF.x, pointF.y, paint);
 }
 /**
 * 生成干擾線
 */
 private static void drawLine(Canvas canvas, Paint paint) {
 int startX = mRandom.nextInt(mWidth);
 int startY = mRandom.nextInt(mHeight);
 int endX = mRandom.nextInt(mWidth);
 int endY = mRandom.nextInt(mHeight);
 canvas.drawLine(startX, startY, endX, endY, paint);
 }
 /**
 * 獲取驗證碼
 *
 * @param length 生成隨機數的長度
 * @param contains 是否包含字符串
 * @return
 */
 public String getValidationCode(int length,boolean contains) {
 String val = "";
 Random random = new Random();
 for (int i = 0; i < length; i++) {
  if (contains){
  //字母或數字
  String code = random.nextInt(2) % 2 == 0 ? "char" : "num";
  //字符串
  if ("char".equalsIgnoreCase(code)) {
   //大寫或小寫字母
   int choice = random.nextInt(2) % 2 == 0 ? 65 : 97;
   val += (char) (choice + random.nextInt(26));
  } else if ("num".equalsIgnoreCase(code)) {
   val += String.valueOf(random.nextInt(10));
  }
  }else{
  val += String.valueOf(random.nextInt(10));
  }
 }
 return val;
 }
 /**
 *判斷驗證碼是否一致 忽略大小寫
 */
 public Boolean isEqualsIgnoreCase(String CodeString) {
 return mCodeText.equalsIgnoreCase(CodeString);
 }
 /**
 * 判斷驗證碼是否一致 不忽略大小寫
 */
 public Boolean isEquals(String CodeString) {
 return mCodeText.equals(CodeString);
 }
 /**
 * 提供外部調用的刷新方法
 */
 public void refresh(){
 mCodeText= getValidationCode(mCodeLength,isContainChar);
 bitmap = createBitmapValidate();
 invalidate();
 }
}