Android本地驗(yàn)證碼的生成代碼

更新時(shí)間：2021年01月28日 14:40:30 作者：Loften_93663469

這篇文章主要為大家詳細(xì)介紹了Android本地驗(yàn)證碼的生成，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

android客戶端生成本地驗(yàn)證碼主要用來(lái)限制用戶隨意按請(qǐng)求按鈕，其實(shí)該示例也是來(lái)對(duì)自定義view的練練手而已，先給出效果圖吧

其中可定制：

＊干擾線數(shù)目
＊干擾點(diǎn)數(shù)目
＊背景顏色
＊驗(yàn)證碼字體大小及字?jǐn)?shù)

相信以上可以滿足一般的需要了吧，不夠的話可自行添加，下面就來(lái)講實(shí)現(xiàn)的步驟了

繼承view，重寫(xiě)構(gòu)造方法，并初始化所需參數(shù)

public class ValidationCode extends View {

 private Paint mTextPaint;//文字畫(huà)筆
 private Paint mPointPaint;//干擾點(diǎn)畫(huà)筆
 private Paint mPathPaint;//干擾線畫(huà)筆
 private Paint mBitmapPaint;//Bitmap圖畫(huà)筆
 private String mCodeString;//隨機(jī)驗(yàn)證碼
 private int mCodeCount;//驗(yàn)證碼位數(shù)
 private float mTextSize;//驗(yàn)證碼字符大小
 private int mPointNumber;//干擾點(diǎn)數(shù)目
 private int mLineNumber;//干擾線數(shù)目
 private int mBackGround;//背景顏色
 private float mTextWidth;//驗(yàn)證碼字符串的顯示寬度
 private static int mWidth;//控件的寬度
 private static int mHeight;//控件的高度
 private static Random mRandom = new Random();
 private Bitmap bitmap = null;//生成驗(yàn)證碼圖片


 public ValidationCode(Context context) {
  this(context, null);
 }

 public ValidationCode(Context context, AttributeSet attrs) {
  super(context, attrs);
  getAttrValues(context, attrs);
  init();
 }

 /**
  * 獲取布局文件中的值
  */
 private void getAttrValues(Context context, AttributeSet attrs) {
  TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ValidationCode);
  mCodeCount = typedArray.getInteger(R.styleable.ValidationCode_CodeCount, 4);
  mPointNumber = typedArray.getInteger(R.styleable.ValidationCode_PointNumber, 100);
  mLineNumber = typedArray.getInteger(R.styleable.ValidationCode_LineNumber, 2);
  mTextSize = typedArray.getDimension(R.styleable.ValidationCode_CodeTextSize, 20);
  mBackGround = typedArray.getColor(R.styleable.ValidationCode_BackGround,Color.WHITE);
  typedArray.recycle();
 }

 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));

 }

 /**
  * 初始化畫(huà)筆
  */
 private void init() {
  //生成隨機(jī)數(shù)字和字母組合
  mCodeString = getValidationCode(mCodeCount);
  //初始化文字畫(huà)筆
  mTextPaint = new Paint();
  mTextPaint.setStrokeWidth(3);
  mTextPaint.setTextSize(mTextSize);
  //初始化干擾點(diǎn)畫(huà)筆
  mPointPaint = new Paint();
  mPointPaint.setStrokeWidth(4);
  mPointPaint.setStrokeCap(Paint.Cap.ROUND);//設(shè)置斷點(diǎn)處為圓形
  //初始化干擾線畫(huà)筆
  mPathPaint = new Paint();
  mPathPaint.setStrokeWidth(5);
  mPathPaint.setColor(Color.GRAY);
  mPathPaint.setStyle(Paint.Style.STROKE);//設(shè)置畫(huà)筆為空心
  mPathPaint.setStrokeCap(Paint.Cap.ROUND);//設(shè)置斷點(diǎn)處為圓形
  //初始化Bitmap畫(huà)筆
  mBitmapPaint = new Paint();
  mBitmapPaint.setColor(Color.RED);
  //取得驗(yàn)證碼字符串顯示的寬度值
  mTextWidth = mTextPaint.measureText(mCodeString);

 }
}

getAttrValues方法是用來(lái)配置自定義的屬性，需要在 values 中新建 * attrs.xml * 文件，并加上自定義的屬性，如下：

<?xml version="1.0" encoding="utf-8"?>
<resources>
 <declare-styleable name="ValidationCode">
  <attr name="CodeCount" format="integer"/>
  <attr name="PointNumber" format="integer"/>
  <attr name="LineNumber" format="integer"/>
  <attr name="CodeTextSize" format="dimension"/>
  <attr name="BackGround" format="color"/>
 </declare-styleable>
</resources>

onMeasure方法則是在你需要對(duì)自定義的view的大小做出處理時(shí)，通過(guò)setMeasuredDimension設(shè)置該控件大小，下面給出重新定義的寬高代碼塊

/**
* 對(duì)view的寬高進(jìn)行重新定義
*/
private int measureWidth(int measureSpec) {
 int result = 0;
 int specMode = MeasureSpec.getMode(measureSpec);
 int specSize = MeasureSpec.getSize(measureSpec);

 if (specMode == MeasureSpec.EXACTLY) {
  result = specSize;
 } else {
  result = (int) (mTextWidth * 2.0f);
  if (specMode == MeasureSpec.AT_MOST) {
   result = Math.min(result, specSize);
  }
 }
 return result;
}

private int measureHeight(int measureSpec) {
 int result = 0;

 int specMode = MeasureSpec.getMode(measureSpec);
 int specSize = MeasureSpec.getSize(measureSpec);

 if (specMode == MeasureSpec.EXACTLY) {
  result = specSize;
 } else {
  result = (int) (mTextWidth / 1.5f);
  if (specMode == MeasureSpec.AT_MOST) {
   result = Math.min(result, specSize);
  }
 }
 return result;
}

重寫(xiě)onDraw()，繪制圖形

1、繪制驗(yàn)證碼文本字符串，干擾點(diǎn)，干擾線，生成驗(yàn)證碼的bitmap圖

/**
 * 獲取驗(yàn)證碼
 *
 * @param length 生成隨機(jī)數(shù)的長(zhǎng)度
 * @return
 */
public static String getValidationCode(int length) {
 String val = "";
 Random random = new Random();
 for (int i = 0; i < length; i++) {
  //字母或數(shù)字
  String code = random.nextInt(2) % 2 == 0 ? "char" : "num";
  //字符串
  if ("char".equalsIgnoreCase(code)) {
   //大寫(xiě)或小寫(xiě)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));
  }
 }
 return val;
}

/**
 * 生成干擾點(diǎn)
 */
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);
}

/**
 1. 繪制驗(yàn)證碼并返回
 */
private Bitmap generateValidate(){
 if(bitmap != null && !bitmap.isRecycled()){
  //回收并且置為null
  bitmap.recycle();
  bitmap = null;
 }
 //創(chuàng)建圖片和畫(huà)布
 Bitmap sourceBitmap = Bitmap.createBitmap(mWidth,mHeight, Bitmap.Config.ARGB_8888);
 Canvas canvas = new Canvas(sourceBitmap);

 //畫(huà)背景顏色
 canvas.drawColor(mBackGround);

 //畫(huà)上驗(yàn)證碼
 int length = mCodeString.length();
 float charLength = mTextWidth / length;
 for (int i = 1; i <= length; i++) {
  int offsetDegree = mRandom.nextInt(15);
  //這里只會(huì)產(chǎn)生0和1，如果是1那么正旋轉(zhuǎn)正角度，否則旋轉(zhuǎn)負(fù)角度
  offsetDegree = mRandom.nextInt(2) == 1 ? offsetDegree : -offsetDegree;
  canvas.save();
  canvas.rotate(offsetDegree, mWidth / 2, mHeight / 2);
  //給畫(huà)筆設(shè)置隨機(jī)顏色
  mTextPaint.setARGB(255, mRandom.nextInt(200) + 20, mRandom.nextInt(200) + 20,
    mRandom.nextInt(200) + 20);
  canvas.drawText(String.valueOf(mCodeString.charAt(i - 1)), (i - 1) * charLength * 1.6f + 30,
    mHeight * 2 / 3f, mTextPaint);
  canvas.restore();
 }

 //產(chǎn)生干擾效果1 －－ 干擾點(diǎn)
 for (int i = 0; i < mPointNumber; i++) {
  mPointPaint.setARGB(255, mRandom.nextInt(200) + 20, mRandom.nextInt(200) + 20,
    mRandom.nextInt(200) + 20);
  drawPoint(canvas, mPointPaint);
 }

 //生成干擾效果2 －－ 干擾線
 for (int i = 0; i < mLineNumber; i++) {
  mPathPaint.setARGB(255, mRandom.nextInt(200) + 20, mRandom.nextInt(200) + 20,
    mRandom.nextInt(200) + 20);
  drawLine(canvas, mPathPaint);
 }

 canvas.save();
 return sourceBitmap;
}

2、實(shí)現(xiàn)onDraw()方法，繪畫(huà)出驗(yàn)證碼

@Override
protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);

 //獲取控件的寬和高
 mHeight = getHeight();
 mWidth = getWidth();

 if(bitmap == null){
  bitmap = generateValidate();
 }
 canvas.drawBitmap(bitmap,0,0,mBitmapPaint);
}

添加觸摸事件，點(diǎn)擊切換驗(yàn)證碼

@Override
public boolean onTouchEvent(MotionEvent event) {
 switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN:
   mCodeString = getValidationCode(mCodeCount);
   bitmap = generateValidate();
   invalidate();
   break;
  default:
   break;
 }
 return super.onTouchEvent(event);
}

添加公開(kāi)使用方法

我們總是需要提供給用戶調(diào)用的方法，判斷驗(yàn)證碼是否一致之類的，方便用戶進(jìn)一步的操作，這里提供個(gè)幾個(gè)方法

/**
 * 判斷驗(yàn)證碼是否一致
 *
 * @String CodeString
 * 這里忽略大小寫(xiě)
 */
public Boolean isEqualsIgnoreCase(String CodeString) {
 return mCodeString.equalsIgnoreCase(CodeString);
}

/**
 * 判斷驗(yàn)證碼是否一致
 * 不忽略大小寫(xiě)
 */
public Boolean isEquals(String CodeString) {
 return mCodeString.equals(CodeString);
}

/**
 * 外界控件調(diào)用刷新驗(yàn)證碼圖片
 */
public void refresh(){
 mCodeString = getValidationCode(mCodeCount);
 bitmap = generateValidate();
 invalidate();
}

以上就是生成本地驗(yàn)證碼的一個(gè)簡(jiǎn)單的自定義view步驟，這里就給出源碼地址，有需要的就去看看。

以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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