android 客戶端生成隨機驗證碼的實現

由於項目中要用到驗證碼，自己找了些資料，試著就把這個驗證碼給做了出來，代碼不是很多，比較的簡單，下面給大家看看我是怎麼實現該功能的：

首先當然是寫XML咯，貼上代碼

下面貼一下MainActivity的代碼:

裡面的注釋很詳細，就不多說了！

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; //圖標
    Button vc_shuaixi,vc_ok; //確定和刷新驗證碼
    String getCode=null; //獲取驗證碼的值
    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(); //獲取顯示的驗證碼
		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, 沒有填寫驗證碼, 2).show();
			}else if(!v_code.equals(getCode)){
				Toast.makeText(MainActivity.this, 驗證碼填寫不正確, 2).show();
			}else{
				Toast.makeText(MainActivity.this, 操作成功, 2).show();
			}
			
			}
		});
		
	}

最後貼一下做驗證碼必須的一個類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;//驗證碼的長度  這裡是4位
	private static final int DEFAULT_FONT_SIZE = 60;//字體大小
	private static final int DEFAULT_LINE_NUMBER = 3;//多少條干擾線
	private static final int BASE_PADDING_LEFT = 20; //左邊距
	private static final int RANGE_PADDING_LEFT = 35;//左邊距范圍值  
	private static final int BASE_PADDING_TOP = 42;//上邊距
	private static final int RANGE_PADDING_TOP = 15;//上邊距范圍值
	private static final int DEFAULT_WIDTH = 200;//默認寬度.圖片的總寬
	private static final int DEFAULT_HEIGHT = 70;//默認高度.圖片的總高
	private  final int DEFAULT_COLOR=0xdf;//默認背景顏色值
	
	//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;//保存生成的驗證碼
	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為粗體，false為非粗體
		float skewX = random.nextInt(11) / 10;
		skewX = random.nextBoolean() ? skewX : -skewX;
		paint.setTextSkewX(skewX); //float類型參數，負數表示右斜，整數左斜
//		paint.setUnderlineText(true); //true為下劃線，false為非下劃線
//		paint.setStrikeThruText(true); //true為刪除線，false為非刪除線
	}
	
	private void randomPadding() {
		padding_left += base_padding_left + random.nextInt(range_padding_left);
		padding_top = base_padding_top + random.nextInt(range_padding_top);
	}
}

代碼已經貼完畢，可以試著做一下！