android client随机验证码生成函数

由于该项目使用验证码。自己找了一些资料。尽量把这个验证码做出来。代码不是很，較的简单，以下给大家看看我是怎么实现该功能的：

源代码地址下载：http://download.csdn.net/detail/u014608640/7268905

首先当然是写XML咯，贴上代码

 <LinearLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:orientation="horizontal"
       android:id="@+id/yh"
       >

       <TextView
           android:text="username:"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           />

       <EditText
           android:layout_width="fill_parent"
           android:layout_height="wrap_content"
           />

   </LinearLayout>

   <LinearLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:orientation="horizontal"
       android:layout_below="@id/yh"
       android:id="@+id/pwd"
       >

       <TextView
           android:text="password:"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           />

       <EditText
           android:layout_width="fill_parent"
           android:layout_height="wrap_content"
           />

   </LinearLayout>

   <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center_vertical"
                android:layout_marginTop="4dp"
                android:orientation="horizontal"
                android:layout_below="@id/pwd"
                android:id="@+id/code"
                 >

                <LinearLayout
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginBottom="10dp"
                    android:layout_marginLeft="10dp"
                    android:layout_marginRight="10dp"
                    android:layout_marginTop="5dp"
                    android:orientation="horizontal" >

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginLeft="20dp"
                        android:layout_marginRight="5dp"
                        android:text="验 证 码:"
                        android:textColor="#000000" />

                    <EditText
                        android:id="@+id/vc_code"
                        android:layout_width="60dp"
                        android:layout_height="wrap_content"
                        android:layout_weight="1"
                        android:background="#0000"
                        android:maxLength="4"
                        android:paddingBottom="10dp"
                        android:paddingLeft="10dp"
                        android:paddingTop="10dp"
                        android:textColor="#000000"
                        android:textSize="14sp" />
                </LinearLayout>

                <ImageView
                    android:id="@+id/vc_image"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"
                    android:layout_marginBottom="10dp"
                    android:layout_marginTop="5dp"
                    android:layout_weight="1" />

                <Button
                    android:id="@+id/vc_shuaixi"
                    android:layout_width="40dp"
                    android:layout_height="wrap_content"
                    android:background="@android:color/transparent"
                    android:layout_gravity="center_vertical"
                    android:text="刷新验证码"
                    android:textStyle="italic"
                    android:layout_marginTop="5dp"
                    android:layout_marginBottom="10dp"
                    android:layout_marginLeft="5dp"
                    android:layout_marginRight="5dp"
                    android:textColor="#7f7f7f"
                    android:textSize="12sp" />
            </LinearLayout>

   <LinearLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:layout_below="@id/code"
       android:orientation="horizontal"
       >
       <Button
           android:id="@+id/vc_ok"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:text="确定"
           />

   </LinearLayout>

以下贴一下MainActivity的代码:

里面的凝视非常具体。就不多说了！

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
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.Toast;

public class MainActivity extends Activity {

    ImageView vc_image; //图标
    Button vc_shuaixi,vc_ok; //确定和刷新验证码
    String getCode=null; //获取验证码的值
    EditText vc_code; //文本框的值

	@Override
	protected 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
		Log.e("info", getCode+"----");
		vc_shuaixi=(Button)findViewById(R.id.vc_shuaixi);
		vc_shuaixi.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				vc_image.setImageBitmap(Code.getInstance().getBitmap());
				getCode=Code.getInstance().getCode();
			}
		});

		vc_ok=(Button)findViewById(R.id.vc_ok);
		vc_ok.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
			String	v_code=vc_code.getText().toString().trim();
			if(v_code==null||v_code.equals("")){
				Toast.makeText(MainActivity.this, "没有填写验证码", 2).show();
			}else if(!v_code.equals(getCode)){
				Toast.makeText(MainActivity.this, "验证码填写不对", 2).show();
			}else{
				Toast.makeText(MainActivity.this, "操作成功", 2).show();
			}

			}
		});

	}

最后贴一下做验证码必须的一个类Code:

import java.util.Random;

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

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;
	}
	//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 = 70;//默认高度.图片的总高
	private  final int DEFAULT_COLOR=0xdf;//默认背景颜色值

	//settings decided by the layout xml
	//canvas width and height
	private int width = DEFAULT_WIDTH;
	private int height = DEFAULT_HEIGHT; 

	//random word space and pading_top
	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;

	//number of chars, lines; font size
	private int codeLength = DEFAULT_CODE_LENGTH;
	private int line_number = DEFAULT_LINE_NUMBER;
	private int font_size = DEFAULT_FONT_SIZE;

	//variables
	private String code;//保存生成的验证码
	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 );//保存
		c.restore();//
		return bp;
	}

	public String getCode() {
		return code.toLowerCase();
	}

	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类型參数，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
	}

	private void randomPadding() {
		padding_left += base_padding_left + random.nextInt(range_padding_left);
		padding_top = base_padding_top + random.nextInt(range_padding_top);
	}
}

代码已经贴完成。能够试着做一下。

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