1.自定义View——支撑设置画笔色彩，画笔宽度，画板色彩，铲除画板，查看是否有签名，保存画板图片(仿制粘贴可直接使用)

/***CreatedbyYyyyQon2020/3/5.

*电子签名*/publicclassSignatureViewextendsView{privateContextcontext;//X轴起点privatefloatx;//Y轴起点privatefloaty;//画笔privatefinalPaintpaint=newPaint();//途径privatefinalPathpath=newPath();//画布privateCanvascanvas;//生成的图片privateBitmapbitmap;//画笔的宽度privateintpaintWidth=10;//签名色彩privateintpaintColor=Color.BLACK;//布景色彩privateintbackgroundColor=Color.WHITE;//是否现已签名privatebooleanisTouched=false;//签名开始与结束publicinterfaceTouch{voidOnTouch(booleanisTouch);

}privateTouchtouch;publicSignatureView(Contextcontext){super(context);

init(context);

}publicSignatureView(Contextcontext,@NullableAttributeSetattrs){super(context,attrs);

init(context);

}publicSignatureView(Contextcontext,@NullableAttributeSetattrs,intdefStyleAttr){super(context,attrs,defStyleAttr);

init(context);

}privatevoidinit(Contextcontext){this.context=context;//抗锯齿paint.setAntiAlias(true);//样式paint.setStyle(Paint.Style.STROKE);//画笔色彩paint.setColor(paintColor);//画笔宽度paint.setStrokeWidth(paintWidth);

}

@OverrideprotectedvoidonSizeChanged(intw,inth,intoldw,intoldh){super.onSizeChanged(w,h,oldw,oldh);//创建于view巨细一致的bitmapbitmap=Bitmap.createBitmap(getWidth(),getHeight(),Bitmap.Config.ARGB_8888);

canvas=newCanvas(bitmap);

canvas.drawColor(backgroundColor);

isTouched=false;

}

@OverridepublicbooleanonTouchEvent(MotionEventevent){if(touch!=null)touch.OnTouch(true);switch(event.getAction()){//手指按下caseMotionEvent.ACTION_DOWN:

touchDwon(event);break;//手指移动caseMotionEvent.ACTION_MOVE:

isTouched=true;if(touch!=null)touch.OnTouch(false);

touchMove(event);break;//手指抬起caseMotionEvent.ACTION_UP:

canvas.drawPath(path,paint);

path.reset();break;

}//更新制作invalidate();returntrue;

}

@OverrideprotectedvoidonDraw(Canvascanvas){super.onDraw(canvas);//画此次笔画之前的签名canvas.drawBitmap(bitmap,0,0,paint);//通过画布制作多点构成的图形canvas.drawPath(path,paint);

}//手指按下的办法privatevoidtouchDwon(MotionEventevent){//重置制作途径path.reset();floatdownX=event.getX();floatdownY=event.getY();

x=downX;

y=downY;//制作起点path.moveTo(downX,downY);

}//手指滑动的办法privatevoidtouchMove(MotionEventevent){//当前的x,y坐标点finalfloatmoveX=event.getX();finalfloatmoveY=event.getY();//之前的x,y坐标点finalfloatpreviousX=x;finalfloatpreviousY=y;//获取绝对值finalfloatdx=Math.abs(moveX-previousX);finalfloatdy=Math.abs(moveY-previousY);if(dx>=3||dy>=3){floatcX=(moveX+previousX)/2;floatcY=(moveY+previousY)/2;

path.quadTo(previousX,previousY,cX,cY);

x=moveX;

y=moveY;

}

}/***设置画笔色彩

*

*@parampaintColor*/publicvoidsetPaintColor(intpaintColor){this.paintColor=paintColor;

paint.setColor(paintColor);

}/***设置画笔宽度

*

*@parampaintWidth*/publicvoidsetPaintWidth(intpaintWidth){this.paintWidth=paintWidth;

paint.setStrokeWidth(paintWidth);

}/***设置画板色彩

*

*@paramcanvasColor*/publicvoidsetCanvasColor(intcanvasColor){this.backgroundColor=canvasColor;

}/***铲除画板*/publicvoidclear(){if(canvas!=null){

isTouched=false;//更新画板paint.setColor(paintColor);

paint.setStrokeWidth(paintWidth);

canvas.drawColor(backgroundColor,PorterDuff.Mode.CLEAR);

invalidate();

}

}/***获取画板的Bitmap

*

*@return*/publicBitmapgetBitmap(){

setDrawingCacheEnabled(true);

buildDrawingCache();

Bitmapbitmap=getDrawingCache();

setDrawingCacheEnabled(false);returnbitmap;

}/***是否有签名

*

*@return*/publicBooleangetSigstatus(){returnisTouched;

}/***保存画板

*

*@parampath保存到途径*/@SuppressLint(“WrongThread”)publicBooleansave(Stringpath)throwsIOException{

Bitmapbitmap=this.bitmap;

ByteArrayOutputStreambos=newByteArrayOutputStream();

bitmap.compress(Bitmap.CompressFormat.PNG,100,bos);byte[]buffer=bos.toByteArray();if(buffer!=null){

Filefile=newFile(path);if(file.exists()){

file.delete();

}

OutputStreamoutputStream=newFileOutputStream(file);

outputStream.write(buffer);

outputStream.close();returntrue;

}else{returnfalse;

}

}

}

2.xml布局引用自定义View(留意包名)

android:layout_width=”match_parent”android:layout_height=”match_parent”android:orientation=”vertical”>

android:id=”@+id/signature”android:layout_width=”match_parent”android:layout_height=”0dp”android:layout_weight=”1″android:background=”#fff”/>

android:layout_width=”match_parent”android:layout_height=”50dp”android:layout_margin=”20dp”android:orientation=”horizontal”>

android:id=”@+id/clear”android:layout_width=”0dp”android:layout_height=”match_parent”android:layout_weight=”1″android:gravity=”center”android:text=”铲除”/>

android:id=”@+id/isSignature”android:layout_width=”0dp”android:layout_height=”match_parent”android:layout_marginLeft=”10dp”android:layout_weight=”1″android:gravity=”center”android:text=”是否签名”/>

android:id=”@+id/save”android:layout_width=”0dp”android:layout_height=”match_parent”android:layout_marginLeft=”10dp”android:layout_weight=”1″android:gravity=”center”android:text=”保存”/>

3.Activity调用

/**

*CreatedbyYyyyQon2020/3/9.

*/

publicclassSignatureActivityextendsAppCompatActivity{

@Override

protectedvoidonCreate(@NullableBundlesavedInstanceState){

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_signature);

SignatureViewsignatureView=findViewById(R.id.signature);

//设置画笔色彩(能够不设置–默许画笔宽度10,画笔色彩黑,布景色彩白)

signatureView.setPaintColor(Color.BLACK);

signatureView.setPaintWidth(20);

signatureView.setCanvasColor(Color.WHITE);

//铲除

Buttonclear=findViewById(R.id.clear);

clear.setOnClickListener(view->{

signatureView.clear();

//设置画笔色彩(能够不设置–默许画笔宽度10,画笔色彩黑,布景色彩白)

signatureView.setPaintColor(Color.BLACK);

signatureView.setPaintWidth(20);

signatureView.setCanvasColor(Color.WHITE);

});

//是否含有签名

ButtonisSignature=findViewById(R.id.isSignature);

isSignature.setOnClickListener(view->{

if(signatureView.getSigstatus()){

Toast.makeText(SignatureActivity.this,”有签名”,Toast.LENGTH_SHORT).show();

}else{

Toast.makeText(SignatureActivity.this,”无签名”,Toast.LENGTH_SHORT).show();

}

});

//保存

Buttonsave=findViewById(R.id.save);

save.setOnClickListener(view->{

try{

if(signatureView.save(“/sdcard/YyyyQ.png”)){

Toast.makeText(SignatureActivity.this,”保存成功”,Toast.LENGTH_SHORT).show();

}else{

Toast.makeText(SignatureActivity.this,”保存失败”,Toast.LENGTH_SHORT).show();

}

}catch(IOExceptione){

e.printStackTrace();

}

});

}

}