Android签名捕获 [英] Android Signature Capture

问题描述

我正在开发android应用程序.在我的项目中，我有一个有关签名捕获的任务，即用户应将他/她的签名保留在移动设备的屏幕上，然后单击保存按钮单击该签名必须将其存储在数据库中.我已经搜索并找到了一些链接，但仍然没有找到确切的解决方案. 我也尝试过TouchPaint.java，但是在那里我没有找到用于布局的xml文件. 您能给我们推荐一些示例代码吗?我将感谢你....

I am working on android application. In my project I have a task regarding signature capture i.e the user should keep his/her signature on the screen of the mobile and once save button is clicked the signature has to stored in the database. I have searched and found some links but still I didn't find the exact solution. I also tried TouchPaint.java but there I didnt find the xml file for layout. Could you please suggest us with some sample code? I will be thankful to you....

推荐答案

这是Has AlTaiar的C#签名视图的有效Java版本， 花了我一段时间才能使其正常工作100％

Here is the working Java version of Has AlTaiar's C# Signature View, Took me a while to get it to work 100% correctly

public class CaptureSignatureView extends View {

    private Bitmap _Bitmap;
    private Canvas _Canvas;
    private Path _Path;
    private Paint _BitmapPaint;
    private Paint _paint;
    private float _mX;
    private float _mY;
    private float TouchTolerance = 4;
    private float LineThickness = 4;

    public CaptureSignatureView(Context context, AttributeSet attr) {
        super(context, attr);
        _Path = new Path();
        _BitmapPaint = new Paint(Paint.DITHER_FLAG);
        _paint = new Paint();
        _paint.setAntiAlias(true);
        _paint.setDither(true);
        _paint.setColor(Color.argb(255, 0, 0, 0));
        _paint.setStyle(Paint.Style.STROKE);
        _paint.setStrokeJoin(Paint.Join.ROUND);
        _paint.setStrokeCap(Paint.Cap.ROUND);
        _paint.setStrokeWidth(LineThickness);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        _Bitmap = Bitmap.createBitmap(w, (h > 0 ? h : ((View) this.getParent()).getHeight()), Bitmap.Config.ARGB_8888);
        _Canvas = new Canvas(_Bitmap);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawColor(Color.WHITE);
        canvas.drawBitmap(_Bitmap, 0, 0, _BitmapPaint);
        canvas.drawPath(_Path, _paint);
    }

    private void TouchStart(float x, float y) {
        _Path.reset();
        _Path.moveTo(x, y);
        _mX = x;
        _mY = y;
    }

    private void TouchMove(float x, float y) {
        float dx = Math.abs(x - _mX);
        float dy = Math.abs(y - _mY);

        if (dx >= TouchTolerance || dy >= TouchTolerance) {
            _Path.quadTo(_mX, _mY, (x + _mX) / 2, (y + _mY) / 2);
            _mX = x;
            _mY = y;
        }
    }

    private void TouchUp() {
        if (!_Path.isEmpty()) {
            _Path.lineTo(_mX, _mY);
            _Canvas.drawPath(_Path, _paint);
        } else {
            _Canvas.drawPoint(_mX, _mY, _paint);
        }

        _Path.reset();
    }

    @Override
    public boolean onTouchEvent(MotionEvent e) {
        super.onTouchEvent(e);
        float x = e.getX();
        float y = e.getY();

        switch (e.getAction()) {
            case MotionEvent.ACTION_DOWN:
                TouchStart(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_MOVE:
                TouchMove(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                TouchUp();
                invalidate();
                break;
        }

        return true;
    }

    public void ClearCanvas() {
        _Canvas.drawColor(Color.WHITE);
        invalidate();
    }

    public byte[] getBytes() {
        Bitmap b = getBitmap();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        b.compress(Bitmap.CompressFormat.PNG, 100, baos);
        return baos.toByteArray();
    }

    public Bitmap getBitmap() {
        View v = (View) this.getParent();
        Bitmap b = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        v.layout(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
        v.draw(c);

        return b;
    }
}

我尝试了罗布·克罗尔(Rob Croll)的建议，该建议效果很好，但它是直线的，使签名看起来不像人.如果您知道我的意思:P

I tried Rob Croll's suggestion, which worked good, but it is straight liney, rendering the signature not human looking. If you know what I mean :P

这是将视图追加到空的线性布局上的方式

Here is how you append the view on an empty linear layout

LinearLayout mContent = (LinearLayout) findViewById(R.id.linearLayout);
CaptureSignatureView mSig = new CaptureSignatureView(this, null);
mContent.addView(mSig, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);

这是获取签名字节或位图的方法

Here is how to get the bytes or Bitmap of the Signature

byte[] signature = mSig.getBytes();
Bitmap signature = mSig.getBitmap();

这篇关于Android签名捕获的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！