GIF压缩有问题，运行很顺滑！！！

1.自定义View——支持设置画笔颜色，画笔宽度，画板颜色，清除画板，检查是否有签名，保存画板图片(复制粘贴可直接使用)

/*** Created by YyyyQ on 2020/3/5.

* 电子签名*/

public class SignatureView extendsView {privateContext context;//X轴起点

private floatx;//Y轴起点

private floaty;//画笔

private final Paint paint = newPaint();//路径

private final Path path = newPath();//画布

privateCanvas canvas;//生成的图片

privateBitmap bitmap;//画笔的宽度

private int paintWidth = 10;//签名颜色

private int paintColor =Color.BLACK;//背景颜色

private int backgroundColor =Color.WHITE;//是否已经签名

private boolean isTouched = false;//签名开始与结束

public interfaceTouch {void OnTouch(booleanisTouch);

}privateTouch touch;publicSignatureView(Context context) {super(context);

init(context);

}publicSignatureView(Context context, @Nullable AttributeSet attrs) {super(context, attrs);

init(context);

}public SignatureView(Context context, @Nullable AttributeSet attrs, intdefStyleAttr) {super(context, attrs, defStyleAttr);

init(context);

}private voidinit(Context context) {this.context =context;//抗锯齿

paint.setAntiAlias(true);//样式

paint.setStyle(Paint.Style.STROKE);//画笔颜色

paint.setColor(paintColor);//画笔宽度

paint.setStrokeWidth(paintWidth);

}

@Overrideprotected void onSizeChanged(int w, int h, int oldw, intoldh) {super.onSizeChanged(w, h, oldw, oldh);//创建于view大小一致的bitmap

bitmap =Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);

canvas= newCanvas(bitmap);

canvas.drawColor(backgroundColor);

isTouched= false;

}

@Overridepublic booleanonTouchEvent(MotionEvent event) {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;

}//更新绘制

invalidate();return true;

}

@Overrideprotected voidonDraw(Canvas canvas) {super.onDraw(canvas);//画此次笔画之前的签名

canvas.drawBitmap(bitmap, 0, 0, paint);//通过画布绘制多点形成的图形

canvas.drawPath(path, paint);

}//手指按下的方法

private voidtouchDwon(MotionEvent event) {//重置绘制路径

path.reset();float downX =event.getX();float downY =event.getY();

x=downX;

y=downY;//绘制起点

path.moveTo(downX, downY);

}//手指滑动的方法

private voidtouchMove(MotionEvent event) {//当前的x,y坐标点

final float moveX =event.getX();final float moveY =event.getY();//之前的x,y坐标点

final float previousX =x;final float previousY =y;//获取绝对值

final float dx = Math.abs(moveX -previousX);final float dy = Math.abs(moveY -previousY);if (dx >= 3 || dy >= 3) {float cX = (moveX + previousX) / 2;float cY = (moveY + previousY) / 2;

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

x=moveX;

y=moveY;

}

}/*** 设置画笔颜色

*

*@parampaintColor*/

public void setPaintColor(intpaintColor) {this.paintColor =paintColor;

paint.setColor(paintColor);

}/*** 设置画笔宽度

*

*@parampaintWidth*/

public void setPaintWidth(intpaintWidth) {this.paintWidth =paintWidth;

paint.setStrokeWidth(paintWidth);

}/*** 设置画板颜色

*

*@paramcanvasColor*/

public void setCanvasColor(intcanvasColor) {this.backgroundColor =canvasColor;

}/*** 清除画板*/

public voidclear() {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

*/

publicBitmap getBitmap() {

setDrawingCacheEnabled(true);

buildDrawingCache();

Bitmap bitmap=getDrawingCache();

setDrawingCacheEnabled(false);returnbitmap;

}/*** 是否有签名

*

*@return

*/

publicBoolean getSigstatus() {returnisTouched;

}/*** 保存画板

*

*@parampath 保存到路径*/@SuppressLint("WrongThread")public Boolean save(String path) throwsIOException {

Bitmap bitmap= this.bitmap;

ByteArrayOutputStream bos= newByteArrayOutputStream();

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

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

file.delete();

}

OutputStream outputStream= newFileOutputStream(file);

outputStream.write(buffer);

outputStream.close();return true;

}else{return false;

}

}

}

2.xml布局引用自定义View(注意包名)

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="清除" />

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

/**

* Created by YyyyQ on 2020/3/9.

*/

public class SignatureActivity extends AppCompatActivity {

@Override

protected void onCreate(@Nullable Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_signature);

SignatureView signatureView = findViewById(R.id.signature);

//设置画笔颜色(可以不设置--默认画笔宽度10,画笔颜色黑,背景颜色白)

signatureView.setPaintColor(Color.BLACK);

signatureView.setPaintWidth(20);

signatureView.setCanvasColor(Color.WHITE);

//清除

Button clear = findViewById(R.id.clear);

clear.setOnClickListener(view -> {

signatureView.clear();

//设置画笔颜色(可以不设置--默认画笔宽度10,画笔颜色黑,背景颜色白)

signatureView.setPaintColor(Color.BLACK);

signatureView.setPaintWidth(20);

signatureView.setCanvasColor(Color.WHITE);

});

//是否含有签名

Button isSignature = 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

Button save = 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 (IOException e) {

e.printStackTrace();

}

});

}

}