Android实现手写签名

package com.****.*****.widget;
 
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
 
/**
 * This view implements the drawing canvas.
 * <p/>
 * It handles all of the input events and drawing functions.
 * 签名版
 */
public class PaintView extends View {
 private Paint paint;
 private Canvas cacheCanvas;
 private Bitmap cachebBitmap;
 private Path path;
 private OnMoveLisener lisener;
 
 
 public void setSize(int width,int height,OnMoveLisener lisener) {
 this.lisener=lisener;
 init(width,height);
 }
 
 public PaintView(Context context, AttributeSet attrs) {
 super(context, attrs);
 //init(0,0);
 }
 
 public Bitmap getCachebBitmap() {
 return cachebBitmap;
 }
 
 private void init(int width,int height) {
 paint = new Paint();
 paint.setAntiAlias(true);
 paint.setStrokeWidth(3);
 paint.setStyle(Paint.Style.STROKE);
 paint.setColor(Color.BLACK);
 path = new Path();
 cachebBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
 cacheCanvas = new Canvas(cachebBitmap);
 cacheCanvas.drawColor(Color.WHITE);
 }
 
 public void clear() {
 if (cacheCanvas != null) {
 
  paint.setColor(Color.WHITE);
  cacheCanvas.drawPaint(paint);
  paint.setColor(Color.BLACK);
  cacheCanvas.drawColor(Color.WHITE);
  invalidate();
 }
 }
 
 
 @Override
 protected void onDraw(Canvas canvas) {
 // canvas.drawColor(BRUSH_COLOR);
 canvas.drawBitmap(cachebBitmap, 0, 0, null);
 canvas.drawPath(path, paint);
 }
 
 @Override
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 
 int curW = cachebBitmap != null ? cachebBitmap.getWidth() : 0;
 int curH = cachebBitmap != null ? cachebBitmap.getHeight() : 0;
 if (curW >= w && curH >= h) {
  return;
 }
 
 if (curW < w)
  curW = w;
 if (curH < h)
  curH = h;
 
 Bitmap newBitmap = Bitmap.createBitmap(curW, curH, Bitmap.Config.ARGB_8888);
 Canvas newCanvas = new Canvas();
 newCanvas.setBitmap(newBitmap);
 if (cachebBitmap != null) {
  newCanvas.drawBitmap(cachebBitmap, 0, 0, null);
 }
 cachebBitmap = newBitmap;
 cacheCanvas = newCanvas;
 }
 
 private float cur_x, cur_y;
 
 @Override
 public boolean onTouchEvent(MotionEvent event) {
 
 getParent().requestDisallowInterceptTouchEvent(true);// 通知父控件勿拦截本控件touch事件
 
 float x = event.getX();
 float y = event.getY();
 
 switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN: {
  cur_x = x;
  cur_y = y;
  path.moveTo(cur_x, cur_y);
  break;
  }
 
  case MotionEvent.ACTION_MOVE: {
  path.quadTo(cur_x, cur_y, x, y);
  cur_x = x;
  cur_y = y;
  lisener.hideWords();//隐藏提醒的文字
  break;
  }
 
  case MotionEvent.ACTION_UP: {
  cacheCanvas.drawPath(path, paint);
  path.reset();
  break;
  }
 }
 
 invalidate();
 
 return true;
 }
 
 
 public interface OnMoveLisener{
 void hideWords();//主界面回调后隐藏提示文字
 }
}