Android手机生成验证码，可以本地和网络对比

转载自http://blog.youkuaiyun.com/qq_33078541?viewmode=contents

一行代码生成图片和纯文字的验证码，使用起来非常简单

package com.example.testandroi;

import java.util.Random;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

/**
 * Created by GT on 2016/2/26.
 * 博客地址：http://blog.youkuaiyun.com/qq_33078541?viewmode=list
 */
public class CodeUtils {
	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' };

	private static CodeUtils mCodeUtils;
	private int mPaddingLeft, mPaddingTop;
	private StringBuilder mBuilder = new StringBuilder();
	private Random mRandom = new Random();

	// Default Settings
	private static final int DEFAULT_CODE_LENGTH = 4;// 验证码的长度 这里是4位
	private static final int DEFAULT_FONT_SIZE = 60;// 字体大小
	private static final int DEFAULT_LINE_NUMBER = 3;// 多少条干扰线
	private static final int BASE_PADDING_LEFT = 20; // 左边距
	private static final int RANGE_PADDING_LEFT = 35;// 左边距范围值
	private static final int BASE_PADDING_TOP = 42;// 上边距
	private static final int RANGE_PADDING_TOP = 15;// 上边距范围值
	private static final int DEFAULT_WIDTH = 200;// 默认宽度.图片的总宽
	private static final int DEFAULT_HEIGHT = 100;// 默认高度.图片的总高
	private static final int DEFAULT_COLOR = 0xDF;// 默认背景颜色值

	public static CodeUtils getInstance() {
		if (mCodeUtils == null) {
			mCodeUtils = new CodeUtils();
		}
		return mCodeUtils;
	}

	// 生成验证码图片
	public Bitmap createBitmap() {
		mPaddingLeft = 0; // 每次生成验证码图片时初始化
		mPaddingTop = 0;

		Bitmap bitmap = Bitmap.createBitmap(DEFAULT_WIDTH, DEFAULT_HEIGHT,
				Bitmap.Config.ARGB_8888);
		Canvas canvas = new Canvas(bitmap);

		// 生成的验证码
		String code = createCode();

		canvas.drawColor(Color.rgb(DEFAULT_COLOR, DEFAULT_COLOR, DEFAULT_COLOR));
		Paint paint = new Paint();
		paint.setTextSize(DEFAULT_FONT_SIZE);

		for (int i = 0; i < code.length(); i++) {
			randomTextStyle(paint);
			randomPadding();
			canvas.drawText(code.charAt(i) + "", mPaddingLeft, mPaddingTop,
					paint);
		}

		// 干扰线
		for (int i = 0; i < DEFAULT_LINE_NUMBER; i++) {
			drawLine(canvas, paint);
		}

		canvas.save(Canvas.ALL_SAVE_FLAG);// 保存
		canvas.restore();
		return bitmap;
	}

	// 生成验证码
	public String createCode() {
		mBuilder.delete(0, mBuilder.length()); // 使用之前首先清空内容

		for (int i = 0; i < DEFAULT_CODE_LENGTH; i++) {
			mBuilder.append(CHARS[mRandom.nextInt(CHARS.length)]);
		}

		return mBuilder.toString();
	}

	// 生成干扰线
	private void drawLine(Canvas canvas, Paint paint) {
		int color = randomColor();
		int startX = mRandom.nextInt(DEFAULT_WIDTH);
		int startY = mRandom.nextInt(DEFAULT_HEIGHT);
		int stopX = mRandom.nextInt(DEFAULT_WIDTH);
		int stopY = mRandom.nextInt(DEFAULT_HEIGHT);
		paint.setStrokeWidth(1);
		paint.setColor(color);
		canvas.drawLine(startX, startY, stopX, stopY, paint);
	}

	// 随机颜色
	private int randomColor() {
		mBuilder.delete(0, mBuilder.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;
			}

			mBuilder.append(haxString);
		}

		return Color.parseColor("#" + mBuilder.toString());
	}

	// 随机文本样式
	private void randomTextStyle(Paint paint) {
		int color = randomColor();
		paint.setColor(color);
		paint.setFakeBoldText(mRandom.nextBoolean()); // true为粗体，false为非粗体
		float skewX = mRandom.nextInt(11) / 10;
		skewX = mRandom.nextBoolean() ? skewX : -skewX;
		paint.setTextSkewX(skewX); // float类型参数，负数表示右斜，整数左斜
		// paint.setUnderlineText(true); //true为下划线，false为非下划线
		// paint.setStrikeThruText(true); //true为删除线，false为非删除线
	}

	// 随机间距
	private void randomPadding() {
		mPaddingLeft += BASE_PADDING_LEFT + mRandom.nextInt(RANGE_PADDING_LEFT);
		mPaddingTop = BASE_PADDING_TOP + mRandom.nextInt(RANGE_PADDING_TOP);
	}

}

使用的话，Bitmap bitmap=CodeUtils.getInstance().createBitmap();

iamge.setImageBitmap(bitmap);

是不是很简单呢？可以本地保存对比，也可以先传送到后台再进行对比