如何获取在位图画布中绘制的签名的X和Y坐标

Question

下面给出的是我的Java代码。 我想捕获在位图中绘制的签名并将其存储在字符串数组（签名的X和Y坐标）中。

package com.ust.mobile.android.jnj;

import java.util.ArrayList;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.view.MotionEvent;
import android.view.View;

public class SignatureFieldClass extends View{


    private int nBitmapWidth = 700;
    private int nBitmapHeight = 220;

    private Bitmap  mBitmap;
    private Canvas  mCanvas;
    private Path    mPath;
    private Paint   mBitmapPaint;
    private Paint mPaint = new Paint();
    private ArrayList<String> signature=new ArrayList<String>();
    public SignatureFieldClass(Context c) {
        super(c);

        mPaint.setAntiAlias(true);
        mPaint.setDither(true);
        mPaint.setColor(0xFFFF0000);
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(4); 

        mBitmap = Bitmap.createBitmap(nBitmapWidth, nBitmapHeight, Bitmap.Config.ARGB_8888);
        mCanvas = new Canvas(mBitmap);
        mPath = new Path();
        mBitmapPaint = new Paint(Paint.DITHER_FLAG);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawColor(0xFF6386AD);
        canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
        canvas.drawPath(mPath, mPaint);
    }

    private float mX, mY;
    private static final float TOUCH_TOLERANCE = 4;

    private void touch_start(float x, float y) {
        mPath.reset();
        mPath.moveTo(x, y);
        mX = x;
        mY = y;
    }
    private void touch_move(float x, float y) {
        float dx = Math.abs(x - mX);
        float dy = Math.abs(y - mY);
        if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
            mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
            mX = x;
            mY = y;
        }
    }
    private void touch_up() {
        mPath.lineTo(mX, mY);
        // commit the path to our offscreen
        mCanvas.drawPath(mPath, mPaint);
        // kill this so we don't double draw
        mPath.reset();
    }

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

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                touch_start(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_MOVE:
                touch_move(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                touch_up();
                invalidate();
                break;
        }
        return true;
    }



    public void ClearPath(){
         mPath.reset();
         invalidate();
    }
}

Answer 1

我们可以将位图的X和Y坐标存储到字符串数组。对于dat，我们可以使用以下代码。 private int mX，mY; 私有静态最终浮点数TOUCH_TOLERANCE = 4;

private void touch_start(int  x, int y) {
    mPath.reset();
    mPath.moveTo(x, y);
    mX = x;
    s=Integer.toString(mX);
    //signatures=s;
    sb.append(s);
    sb.append(",");
    //signature[0]=s;
    mY = y;
    s=Integer.toString(mY);
    sb.append(s);

    //signature[1]=s;
}
private void touch_move(int x, int y) {
    float dx = Math.abs(x - mX);
    float dy = Math.abs(y - mY);
    if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
        mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
        mX = x;
        s=Integer.toString(mX);
        sb.append(",");
        sb.append(s);
        sb.append(",");
       /* int l=signature.length;
        signature[l]=s;*/
        mY = y;
        s=Integer.toString(mY);
        sb.append(s);

         /*l=signature.length;
         signature[l]=s;*/
    }
}
private void touch_up() {
    mPath.lineTo(mX, mY);
    s=Integer.toString(mX);
    sb.append(",");
    sb.append(s);
    s=Integer.toString(mY);
    sb.append(",");
    sb.append(s);
    sb.append(",");
    // commit the path to our offscreen
    mCanvas.drawPath(mPath, mPaint);
    // kill this so we don't double draw
    mPath.reset();
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    int x = (int)event.getX();
    int y = (int)event.getY();

    switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            touch_start(x, y);
            invalidate();
            break;
        case MotionEvent.ACTION_MOVE:
            touch_move(x, y);
            invalidate();
            break;
        case MotionEvent.ACTION_UP:
            touch_up();
            invalidate();
            break;
    }
    return true;
}

这不是完整的代码。它的d部分代码捕获了x和y坐标。sb是字符串缓冲区。我们可以将d字符串缓冲区中的d值复制到字符串中。