短視頻APP製作刷新驗證碼功能

首先看MainActivity的佈局

<TextView
    android: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="驗證碼:" />

<EditText
    android: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>

<Button
    android: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="確定" />

<Button
    android: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="刷新驗證碼" />

<ImageView
    android: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" />

MainActivity代碼

package com.example.yanzhengma;

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; // 圖片
    Button vc_shuaixi, vc_ok;
    String getCode = null;
    EditText vc_code;

    @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
        vc_shuaixi = (Button) findViewById(R.id.vc_shuaixi);
        vc_shuaixi.setOnClickListener(this);
        vc_ok = (Button) findViewById(R.id.vc_ok);
        vc_ok.setOnClickListener(this);

    }

    @Override
    public 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;
    }

    @Override
    public void onClick(View view) {
        // TODO Auto-generated method stub
        switch (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, "驗證碼爲空", Toast.LENGTH_SHORT).show();
                } else if (!v_code.equals(getCode)) {
                    Toast.makeText(MainActivity.this, "驗證碼錯誤", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(MainActivity.this, "驗證成功", Toast.LENGTH_SHORT).show();
                    Intent itIntent = new Intent(MainActivity.this,
                            secondActivity.class);
                    startActivity(itIntent);
                    MainActivity.this.finish();

                }

                break;
        }
    }

}

好了,到重點部分了,繪製驗證碼

package com.example.yanzhengma;

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;// 驗證碼的長度 這裏是4位
    private static final int DEFAULT_FONT_SIZE = 60;// 字體大小
    private static final int DEFAULT_LINE_NUMBER = 3;// 多少條幹擾線
    private static final int BASE_PADDING_LEFT = 20; // 左邊距
    private static final int RANGE_PADDING_LEFT = 35;// 左邊距範圍值
    private static final int BASE_PADDING_TOP = 42;// 上邊距
    private static final int RANGE_PADDING_TOP = 15;// 上邊距範圍值
    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

    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;// 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);
        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爲粗體，false爲非粗體
        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
    }

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

}