android开发分享android实现手写签名功能

  package com.xx;     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.os.bundle;  import android.support.v7.app.appcompatactivity;  import android.view.motionevent;  import android.view.view;  import android.widget.button;  import android.widget.framelayout;  import android.widget.imageview;  import com.xx.r;     /**   * description: 签名类   * copyright:  copyright (c)2018   * company:      * author:   corwin   * version:   1.0   * date:    2018/9/5 18:32   * modification history:   * date     author   version   description   * ------------------------------------------------------------------   * 2018/9/5  corwin   1.0     1.0 version   */  public class signatureactivity extends appcompatactivity {      private imageview imagesign;   private signatureview mview;      @override public void oncreate(bundle savedinstancestate) {    super.oncreate(savedinstancestate);    setcontentview(r.layout.activity_signature);       imagesign = findviewbyid(r.id.iv_sign);    framelayout framelayout = findviewbyid(r.id.fl_view);       mview = new signatureview(this);    framelayout.addview(mview);    mview.requestfocus();       button btnclear = findviewbyid(r.id.btn_clear);    btnclear.setonclicklistener((v) -> {      mview.clear();    });       button btnok = findviewbyid(r.id.btn_ok);    btnok.setonclicklistener((v) -> {      bitmap imagebitmap = mview.getcachebbitmap();      imagesign.setimagebitmap(imagebitmap);    });   }      /**    * 自定义签名控件    */   class signatureview extends view {       //画笔    private paint paint;       //画布    private canvas cachecanvas;       //位图    private bitmap cachebbitmap;       //图片保存路径    private path path;       //位图缓存    public bitmap getcachebbitmap() {     return cachebbitmap;    }       public signatureview(context context) {     super(context);     init();    }       /**     * 初始化     */    private void init() {     //设置画笔     paint = new paint();     paint.setantialias(true);     paint.setstrokewidth(3);     paint.setstyle(paint.style.stroke);     paint.setcolor(color.black);     path = new path();        //创建位图     cachebbitmap = bitmap.createbitmap(10, 10, bitmap.config.argb_8888);        //用自定义位图构建画布     cachecanvas = new canvas(cachebbitmap);     //设置画布为白色     cachecanvas.drawcolor(color.white);    }       /**     * 清除画板，重置画笔     */    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.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) {     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;       break;      }      case motionevent.action_up: {       cachecanvas.drawpath(path, paint);       path.reset();       break;      }     }     invalidate();     return true;    }   }  }

  <?xml version="1.0"?>  <linearlayout xmlns:android="https://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    >   <imageview     android:id="@+id/iv_sign"     android:layout_width="match_parent"     android:layout_height="0dp"     android:layout_gravity="center"     android:layout_marginbottom="3dp"     android:layout_weight="1"     android:background="@color/white"     />   <framelayout     android:id="@+id/fl_view"     android:layout_width="match_parent"     android:layout_height="0dp"     android:layout_weight="1"     android:background="@color/white"     />   <linearlayout     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:background="@android:drawable/bottom_bar"     android:paddingtop="3dp"     >    <button      android:id="@+id/btn_ok"      android:layout_width="0dp"      android:layout_height="wrap_content"      android:layout_weight="1"      android:text="确定"      />    <button      android:id="@+id/btn_clear"      android:layout_width="0dp"      android:layout_height="wrap_content"      android:layout_weight="1"      android:text="清除"      />   </linearlayout>  </linearlayout>