本文已参与「新人创作礼」活动，一起开启掘金创作之路。
项目中有一个签合同的功能，需要实现签字功能
自定义签字版：
public class SignatureView extends View {
private static final String TAG = SignatureView.class.getSimpleName();
public static final int PEN_WIDTH = 10;
public static final int PEN_COLOR = Color.BLACK;
public static final int BACK_COLOR = Color.WHITE;
//画笔x坐标起点
private float mPenX;
//画笔y坐标起点
private float mPenY;
private Paint mPaint = new Paint();
private Path mPath = new Path();
private Canvas mCanvas;
private Bitmap cacheBitmap;
//画笔宽度
private int mPentWidth = PEN_WIDTH;
//画笔颜色
private int mPenColor = PEN_COLOR;
//画板颜色
private int mBackColor = BACK_COLOR;
private boolean isTouched = false;
private String mSavePath = null;
public SignatureView(Context context) {
this(context, null);
}
public SignatureView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public SignatureView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.SignatureView);
mPenColor = typedArray.getColor(R.styleable.SignatureView_penColor, PEN_COLOR);
mBackColor = typedArray.getColor(R.styleable.SignatureView_backColor, BACK_COLOR);
mPentWidth = typedArray.getInt(R.styleable.SignatureView_penWidth, PEN_WIDTH);
typedArray.recycle();
init();
}
private void init() {
mPaint.setAntiAlias(true);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(mPentWidth);
mPaint.setColor(mPenColor);
}
public boolean getTouched() {
return isTouched;
}
public void setPentWidth(int pentWidth) {
mPentWidth = pentWidth;
}
public void setPenColor(@ColorInt int penColor) {
mPenColor = penColor;
}
public void setBackColor(@ColorInt int backColor) {
mBackColor = backColor;
}
/**
* 清空签名
*/
public void clear() {
if (mCanvas != null) {
isTouched = false;
mCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
mCanvas.drawColor(mBackColor);
invalidate();
}
}
/**
* 保存图片
*
* @param path 保存的地址
* @param clearBlank 是否清除空白区域
* @param blank 空白区域留空距离
* @throws IOException
*/
public void save(String path, boolean clearBlank, int blank) throws IOException {
if (TextUtils.isEmpty(path)) {
return;
}
mSavePath = path;
Bitmap bitmap = cacheBitmap;
if (clearBlank) {
bitmap = clearBlank(bitmap, blank);
}
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, bos);
byte[] buffer = bos.toByteArray();
if (buffer != null) {
File file = new File(path);
if (file.exists()) {
file.delete();
}
OutputStream os = new FileOutputStream(file);
os.write(buffer);
os.close();
bos.close();
}
}
/**
* 获取Bitmap缓存
*/
public Bitmap getBitmap() {
setDrawingCacheEnabled(true);
buildDrawingCache();
Bitmap bitmap = getDrawingCache();
setDrawingCacheEnabled(false);
return bitmap;
}
/**
* 获取保存路径
*/
public String getSavePath() {
return mSavePath;
}
/**
* 逐行扫描，清除边界空白
*
* @param blank 边界留多少个像素
*/
private Bitmap clearBlank(Bitmap bmp, int blank) {
int height = bmp.getHeight();
int width = bmp.getWidth();
int top = 0, left = 0, right = 0, bottom = 0;
int[] pixs = new int[width];
boolean isStop;
//扫描上边距不等于背景颜色的第一个点
for (int i = 0; i < height; i++) {
bmp.getPixels(pixs, 0, width, 0, i, width, 1);
isStop = false;
for (int pix :
pixs) {
if (pix != mBackColor) {
top = i;
isStop = true;
break;
}
}
if (isStop) {
break;
}
}
//扫描下边距不等于背景颜色的第一个点
for (int i = height - 1; i >= 0; i--) {
bmp.getPixels(pixs, 0, width, 0, i, width, 1);
isStop = false;
for (int pix :
pixs) {
if (pix != mBackColor) {
bottom = i;
isStop = true;
break;
}
}
if (isStop) {
break;
}
}
pixs = new int[height];
//扫描左边距不等于背景颜色的第一个点
for (int x = 0; x < width; x++) {
bmp.getPixels(pixs, 0, 1, x, 0, 1, height);
isStop = false;
for (int pix : pixs) {
if (pix != mBackColor) {
left = x;
isStop = true;
break;
}
}
if (isStop) {
break;
}
}
//扫描右边距不等于背景颜色的第一个点
for (int x = width - 1; x > 0; x--) {
bmp.getPixels(pixs, 0, 1, x, 0, 1, height);
isStop = false;
for (int pix : pixs) {
if (pix != mBackColor) {
right = x;
isStop = true;
break;
}
}
if (isStop) {
break;
}
}
if (blank < 0) {
blank = 0;
}
//计算加上保留空白距离之后的图像大小
left = left - blank > 0 ? left - blank : 0;
top = top - blank > 0 ? top - blank : 0;
right = right + blank > width - 1 ? width - 1 : right + blank;
bottom = bottom + blank > height - 1 ? height - 1 : bottom + blank;
return Bitmap.createBitmap(bmp, left, top, right - left, bottom - top);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
cacheBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(cacheBitmap);
mCanvas.drawColor(mBackColor);
isTouched = false;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(cacheBitmap, 0, 0, mPaint);
canvas.drawPath(mPath, mPaint);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mPenX = event.getX();
mPenY = event.getY();
mPath.moveTo(mPenX, mPenY);
return true;
case MotionEvent.ACTION_MOVE:
isTouched = true;
float x = event.getX();
float y = event.getY();
float penX = mPenX;
float penY = mPenY;
float dx = Math.abs(x - penX);
float dy = Math.abs(y - penY);
if (dx >= 3 || dy >= 3) {
float cx = (x + penX) / 2;
float cy = (y + penY) / 2;
mPath.quadTo(penX, penY, cx, cy);
mPenX = x;
mPenY = y;
}
invalidate();
break;
case MotionEvent.ACTION_UP:
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
break;
default:
break;
}
return super.onTouchEvent(event);
}
}
res---->values---->attrs
<!-- 合同手写签名 -->
<declare-styleable name="SignatureView">
<attr format="color" name="penColor"/>
<attr format="color" name="backColor"/>
<attr format="integer" name="penWidth"/>
</declare-styleable>
布局中使用刚刚自定义的签字版：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".view.activity.SignatureActivity">
<TextView
android:id="@+id/btn_clear"
android:layout_width="@dimen/dp_50"
android:layout_height="@dimen/dp_50"
android:gravity="center"
android:text="清空"
android:layout_alignParentBottom="true"
android:layout_toRightOf="@id/back"
android:layout_marginLeft="@dimen/dp_20"
/>
<TextView
android:id="@+id/back"
android:layout_width="@dimen/dp_50"
android:layout_height="@dimen/dp_50"
android:text="返回"
android:layout_alignParentBottom="true"
android:layout_marginLeft="@dimen/dp_20"
android:gravity="center"
/>
<Button
android:id="@+id/btn_save"
android:layout_width="@dimen/dp_100"
android:layout_height="@dimen/dp_40"
android:text="完成"
android:background="@drawable/btn_shape"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:layout_marginRight="@dimen/dp_10"
android:layout_marginBottom="@dimen/dp_10"
/>
<com.lmc.cityrabbit.utils.SignatureView
android:id="@+id/view_signature"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/rectangle_shape"
android:layout_marginBottom="@dimen/dp_50"
/>
</RelativeLayout>
具体实现：
//签名
public class SignatureActivity extends BaseActivity {
@BindView(R.id.back)
TextView back;
@BindView(R.id.btn_clear)
TextView btnClear;
@BindView(R.id.btn_save)
Button btnSave;
@BindView(R.id.view_signature)
SignatureView viewSignature;
private String mPath;
@Override
protected void initView() {
back.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View pView) {
finish();
}
});
btnClear.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View pView) {
viewSignature.clear();
}
});
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View pView) {
if(viewSignature.getTouched()){
try {
viewSignature.save("/sdcard/sign.png", true, 10);
mPath = Environment.getExternalStorageDirectory()+"/sign.png";
Log.e("凉城", mPath);
Toast.makeText(SignatureActivity.this, "图片保存在："+viewSignature.getSavePath(), Toast.LENGTH_SHORT).show();
} catch (IOException pE) {
pE.printStackTrace();
}
}else{
Toast.makeText(SignatureActivity.this, "请先签名", Toast.LENGTH_SHORT).show();
}
Intent intent = new Intent();
intent.putExtra("path", mPath);
setResult(300, intent);
finish();
}
});
}
@Override
protected void initData() {}
@Override
protected int getLayout() {
return R.layout.activity_signature;
}
}
