图形验证码的实现

图形验证码的实现界面如下：

具体实现代码如下：

package com.example.tuxingyanzhengma;import java.util.Random;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;public class Code {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 Code bpUtil;private Code() {};public static Code getInstance() {if (bpUtil == null)bpUtil = new Code();return bpUtil;}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 = 70;// 默认高度.图片的总高private final int DEFAULT_COLOR = 0xdf;// 默认背景颜色值private int width = DEFAULT_WIDTH;private int height = DEFAULT_HEIGHT;private int base_padding_left = BASE_PADDING_LEFT;private int range_padding_left = RANGE_PADDING_LEFT;private int base_padding_top = BASE_PADDING_TOP;private int range_padding_top = RANGE_PADDING_TOP;private int codeLength = DEFAULT_CODE_LENGTH;private int line_number = DEFAULT_LINE_NUMBER;private int font_size = DEFAULT_FONT_SIZE;private String code;// 验证码private int padding_left, padding_top;private Random random = new Random();private Bitmap createBitmap() {padding_left = 0;Bitmap bp = Bitmap.createBitmap(width, height, Config.ARGB_8888);Canvas c = new Canvas(bp);code = createCode();c.drawColor(Color.rgb(DEFAULT_COLOR, DEFAULT_COLOR, DEFAULT_COLOR));Paint paint = new Paint();paint.setTextSize(font_size);for (int i = 0; i < code.length(); i++) {randomTextStyle(paint);randomPadding();c.drawText(code.charAt(i) + "", padding_left, padding_top, paint);}for (int i = 0; i < line_number; i++) {drawLine(c, paint);}c.save(Canvas.ALL_SAVE_FLAG);c.restore();//return bp;}public String getCode() {return code;}public Bitmap getBitmap() {return createBitmap();}private String createCode() {StringBuilder buffer = new StringBuilder();for (int i = 0; i < codeLength; i++) {buffer.append(CHARS[random.nextInt(CHARS.length)]);}return buffer.toString();}private void drawLine(Canvas canvas, Paint paint) {int color = randomColor();int startX = random.nextInt(width);int startY = random.nextInt(height);int stopX = random.nextInt(width);int stopY = random.nextInt(height);paint.setStrokeWidth(1);paint.setColor(color);canvas.drawLine(startX, startY, stopX, stopY, paint);}private int randomColor() {return randomColor(1);}private int randomColor(int rate) {int red = random.nextInt(256) / rate;int green = random.nextInt(256) / rate;int blue = random.nextInt(256) / rate;return Color.rgb(red, green, blue);}private void randomTextStyle(Paint paint) {int color = randomColor();paint.setColor(color);paint.setFakeBoldText(random.nextBoolean()); // true为粗体，false为非粗体float skewX = random.nextInt(11) / 10;skewX = random.nextBoolean() ? skewX : -skewX;paint.setTextSkewX(skewX); // float类型参数，负数表示右斜，整数左斜}private void randomPadding() {padding_left += base_padding_left + random.nextInt(range_padding_left);padding_top = base_padding_top + random.nextInt(range_padding_top);}}package com.example.tuxingyanzhengma;import android.R.string;import android.os.Bundle;import android.app.Activity;import android.content.ClipData.Item;import android.content.Intent;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.ImageView;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity implements OnClickListener {ImageView vc_image; // 图片Button vc_shuaixi, vc_ok;String getCode = null;EditText vc_code;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);vc_image = (ImageView) findViewById(R.id.vc_image);vc_image.setImageBitmap(Code.getInstance().getBitmap());vc_code = (EditText) findViewById(R.id.vc_code);getCode = Code.getInstance().getCode(); // 获取显示的验证码vc_shuaixi = (Button) findViewById(R.id.vc_shuaixi);vc_shuaixi.setOnClickListener(this);vc_ok = (Button) findViewById(R.id.vc_ok);vc_ok.setOnClickListener(this);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic void onClick(View view) {// TODO Auto-generated method stubswitch (view.getId()) {case R.id.vc_shuaixi:vc_image.setImageBitmap(Code.getInstance().getBitmap());getCode = Code.getInstance().getCode();break;case R.id.vc_ok:String v_code = vc_code.getText().toString().trim();if (v_code == null || v_code.equals("")) {Toast.makeText(MainActivity.this, "验证码为空", Toast.LENGTH_SHORT).show();} else if (!v_code.equals(getCode)) {Toast.makeText(MainActivity.this, "验证码错误", Toast.LENGTH_SHORT).show();} else {Toast.makeText(MainActivity.this, "验证成功", Toast.LENGTH_SHORT).show();}break;}}}<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MainActivity" ><TextViewandroid:id="@+id/textView1"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignParentLeft="true"android:layout_alignParentTop="true"android:layout_marginLeft="20dp"android:layout_marginTop="77dp"android:text="验证码:" /><EditTextandroid:id="@+id/vc_code"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignBaseline="@+id/textView1"android:layout_alignBottom="@+id/textView1"android:layout_toRightOf="@+id/textView1"android:ems="10" ><requestFocus /></EditText><Buttonandroid:id="@+id/vc_ok"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignLeft="@+id/vc_image"android:layout_alignRight="@+id/vc_shuaixi"android:layout_below="@+id/vc_shuaixi"android:layout_marginTop="15dp"android:text="确定" /><Buttonandroid:id="@+id/vc_shuaixi"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignRight="@+id/vc_code"android:layout_alignTop="@+id/vc_image"android:layout_marginRight="20dp"android:text="刷新验证码" /><ImageViewandroid:id="@+id/vc_image"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignLeft="@+id/textView1"android:layout_below="@+id/vc_code"android:layout_marginTop="25dp"android:src="@drawable/ic_launcher" /></RelativeLayout>