Android自定义View绘制随机生成图片验证码

<?xml version="1.0" encoding="utf-8"?>
<resources>

 <attr name="text" format="String" />
 <attr name="textColor" format="color" />
 <attr name="textSize" format="dimension" />
 <attr name="bgColor" format="color" />

 <declare-styleable name="CustomView">
  <attr name="text" />
  <attr name="textColor" />
  <attr name="textSize" />
  <attr name="bgColor" />
 </declare-styleable>

</resources>

<RelativeLayout xmlns:android="http://scheR_871_11845@as.android.com/apk/res/android"
 xmlns:custom="http://scheR_871_11845@as.android.com/apk/res-auto"
 android:layout_width="match_parent"
 android:layout_height="match_parent">

 <com.per.customview01.view.CustomView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:padding="10dp"
  custom:bgColor="#FF27FF28"
  custom:text="J2RdWQG"
  custom:textColor="#ff0000"
  custom:textSize="36dp" />

</RelativeLayout>

/**
  * 文本
  */
 private String mText;
 /**
  * 文本的颜色
  */
 privatE int mTextColor;
 /**
  * 文本的大小
  */
 privatE int mTextSize;
 /**
  * 文本的背景颜色
  */
 privatE int mBgCplor;
 private Rect mBound;
 private Paint mPaint;

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

 public CustomView(Context context,AttributeSet attrs) {
  this(context,attrs,0);
 }

 public CustomView(Context context,int defStyleAttr) {
  super(context,defStyleAttr);
  /**
   * 获得我们所定义的自定义样式属性
   */
  TypedArray a = context.getTheme().obtainStyledAttributes(attrs,R.styleable.CustomView,defStyleAttr,0);
  for (int i = 0; i < a.geTindexCount(); i++) {
   int attr = a.geTindex(i);
   switch (attr) {
    case R.styleable.CustomView_text:
     mText = a.getString(attr);
     break;
    case R.styleable.CustomView_textColor:
     // 默认文本颜色设置为黑色
     mTextColor = a.getColor(R.styleable.CustomView_textColor,Color.bLACK);
     break;
    case R.styleable.CustomView_bgColor:
     // 默认文本背景颜色设置为蓝色
     mBgCplor = a.getColor(R.styleable.CustomView_bgColor,Color.bLUE);
     break;
    case R.styleable.CustomView_textSize:
     // 默认设置为16sp，TypeValue也可以把sp转化为px
     mTextSize = a.getDimensionPixelSize(attr,(int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,16,getresources().getDisplaymetrics()));
     break;
   }
  }
  a.recycle();
  // 获得绘制文本的宽和高
  mPaint = new Paint();
  mPaint.setTextSize(mTextSizE);

  mBound = new Rect();
  mPaint.getTextBounds(mText,mText.length(),mBound);
 }

 public CustomView(Context context) {
  super(context);
 }

 public CustomView(Context context,AttributeSet attrs) {
  super(context,attrs);
 }

 public CustomView(Context context) {
  this(context,0);
 }

@Override
 protected void onMeasure(int widthMeasureSpec,int heightMeasureSpeC) {
  super.onMeasure(widthMeasureSpec,heightMeasureSpec);
 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  mPaint.setColor(mBgCplor);
  canvas.drawRect(0,getMeasuredWidth(),getMeasuredHeight(),mPaint);

  mPaint.setColor(mTextColor);
  canvas.drawText(mText,getWidth() / 2 - mBound.width() / 2,getHeight() / 2 + mBound.height() / 2,mPaint);
 }

 @Override
 protected void onMeasure(int widthMeasureSpec,heightMeasureSpec);
  int widthMode = MeasureSpec.getMode(widthMeasureSpec);
  int widthSize = MeasureSpec.getSize(widthMeasureSpec);
  int heighMode = MeasureSpec.getMode(heightMeasureSpec);
  int heighSize = MeasureSpec.getSize(heightMeasureSpec);
  setMeasuredDimension(widthMode == MeasureSpec.EXACTLY ? widthSize : getPaddingLeft() + getPaddingRight() + mBound.width(),heighMode == MeasureSpec.EXACTLY ? heighSize : getPaddingTop() + getPaddingBottom() + mBound.height());
 }

package com.per.customview01.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.View;

import com.per.customview01.R;

import java.util.Random;

/**
 * @author: adan
 * @description:
 * @projectName: CustomView01
 * @date: 2016-06-12
 * @time: 10:26
 */
public class CustomView extends View {
 private static final char[] CHARS = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
 /**
  * 初始化生成随机数的类
  */
 private Random mRandom = new Random();
 /**
  * 初始化可变字符串
  */
 private StringBuffer sb = new StringBuffer();
 /**
  * 文本
  */
 private String mText;
 /**
  * 文本的颜色
  */
 privatE int mTextColor;
 /**
  * 文本的大小
  */
 privatE int mTextSize;
 /**
  * 文本的背景颜色
  */
 privatE int mBgCplor;
 private Rect mBound;
 private Paint mPaint;

 public CustomView(Context context) {
  this(context,mBound);

  this.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    mText = createCode();
    mTextColor = randomColor();
    mBgCplor = randomColor();
    //View重新调用一次draw过程,以起到界面刷新的作用
    posTinvalidate();
   }
  });
 }

 /**
  * 生成验证码
  */
 public String createCode() {
  sb.delete(0,sb.length()); // 使用之前首先清空内容
  for (int i = 0; i < 6; i++) {
   sb.append(CHARS[mRandom.nexTint(CHARs.length)]);
  }
  Log.e("生成验证码",sb.toString());
  return sb.toString();
 }

 /**
  * 随机颜色
  */
 privatE int randomColor() {
  sb.delete(0,sb.length()); // 使用之前首先清空内容
  String haxString;
  for (int i = 0; i < 3; i++) {
   haxString = Integer.toHexString(mRandom.nexTint(0xFF));
   if (haxString.length() == 1) {
    haxString = "0" + haxString;
   }
   sb.append(haxString);
  }
  Log.e("随机颜色","#" + sb.toString());
  return Color.parseColor("#" + sb.toString());
 }

 @Override
 protected void onMeasure(int widthMeasureSpec,heighMode == MeasureSpec.EXACTLY ? heighSize : getPaddingTop() + getPaddingBottom() + mBound.height());
 }

 @Override
 protected void onDraw(Canvas canvas) {
  super.onDraw(canvas);
  mPaint.setColor(mBgCplor);
  canvas.drawRect(0,mPaint);
 }
}