How To Implement Captcha In Android

I want to do captcha in my application. After my initial analysis, I found that most of them recommend to use 'Simplcaptcha'. I gave a shot at it. But my efforts are in vain. The

Solution 1:

You can use the custom view below to show captcha (tune it according to your needs like if you want to have a alphanumeric captcha or you want a skewed captcha)

publicclassCaptchaViewextendsImageView {

private Paint mPaint;
privatestatic String mCaptchaAsText;

publicCaptchaView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init();
}

publicCaptchaView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

publicCaptchaView(Context context) {
    super(context);
    init();
}

privatevoidinit() {
    mPaint = newPaint();
    mPaint.setColor(Color.BLACK);

    initCaptcha();
}

privatestaticvoidinitCaptcha() {
    mCaptchaAsText = "";
    for (inti=0; i < 4; i++) {
        intnumber= (int) (Math.random() * 10);
        mCaptchaAsText += number;
    }
}

@OverrideprotectedvoidonMeasure(int widthMeasureSpec, int heightMeasureSpec) {

    intdesiredWidth=300;
    intdesiredHeight=80;

    intwidthMode= MeasureSpec.getMode(widthMeasureSpec);
    intwidthSize= MeasureSpec.getSize(widthMeasureSpec);
    intheightMode= MeasureSpec.getMode(heightMeasureSpec);
    intheightSize= MeasureSpec.getSize(heightMeasureSpec);

    int width;
    int height;

    // Measure Widthif (widthMode == MeasureSpec.EXACTLY) {
        // Must be this size
        width = widthSize;
    } elseif (widthMode == MeasureSpec.AT_MOST) {
        // Can't be bigger than...
        width = Math.min(desiredWidth, widthSize);
    } else {
        // Be whatever you want
        width = desiredWidth;
    }

    // Measure Heightif (heightMode == MeasureSpec.EXACTLY) {
        // Must be this size
        height = heightSize;
    } elseif (heightMode == MeasureSpec.AT_MOST) {
        // Can't be bigger than...
        height = Math.min(desiredHeight, heightSize);
    } else {
        // Be whatever you want
        height = desiredHeight;
    }

    // MUST CALL THIS
    setMeasuredDimension(width, height);
}

@OverrideprotectedvoidonDraw(Canvas canvas) {
    super.onDraw(canvas);

    mPaint.setTextSize(getMeasuredHeight());
    canvas.drawText(mCaptchaAsText,
            ((canvas.getWidth() - mPaint.measureText(mCaptchaAsText)) / 2),
            getMeasuredHeight(), mPaint);
}

publicstaticbooleanmatch(String value) {
    if (value.equals(mCaptchaAsText)) {
        returntrue;
    } else {
        if (value != null && value.length() > 0)
            initCaptcha();

        returnfalse;
    }
}
}

Solution 2:

A very easy to use, minimal options, on-device Captcha system for Android applications REFER