在Android的数字签名

我想在android中创build数字签名应用程序。 它应该捕获用户签名并将其作为图像存储。 如果有人知道,请让我知道。

Related of "在Android的数字签名"

尝试自定义视图而不是手势:

package com.example.myapp.gui.views; 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.SystemClock; import android.util.AttributeSet; import android.view.MotionEvent; import android.view.View; /** * A simple view to capture a path traced onto the screen. Initially intended to be used to captures signatures. * * @author Andrew Crichton * @version 0.1 */ public class SignatureView extends View { private Path mPath; private Paint mPaint; private Paint bgPaint = new Paint(Color.TRANSPARENT); private Bitmap mBitmap; private Canvas mCanvas; private float curX, curY; private static final int TOUCH_TOLERANCE = 4; private static final int STROKE_WIDTH = 4; public SignatureView(Context context) { super(context); init(); } public SignatureView(Context context, AttributeSet attrs) { super(context, attrs); init(); } public SignatureView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } private void init() { setFocusable(true); mPath = new Path(); mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mPaint.setColor(Color.WHITE); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeWidth(STROKE_WIDTH); } public void setSigColor(int color) { mPaint.setColor(color); } public void setSigColor(int a, int red, int green, int blue) { mPaint.setARGB(a, red, green, blue); } public boolean clearSignature() { if (mBitmap != null) createFakeMotionEvents(); if (mCanvas != null) { mCanvas.drawColor(Color.BLACK); mCanvas.drawPaint(bgPaint); mPath.reset(); invalidate(); } else { return false; } return true; } public Bitmap getImage() { return this.mBitmap; } public void setImage(Bitmap bitmap) { this.mBitmap = bitmap; this.invalidate(); } @Override protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) { int bitmapWidth = mBitmap != null ? mBitmap.getWidth() : 0; int bitmapHeight = mBitmap != null ? mBitmap.getWidth() : 0; if (bitmapWidth >= width && bitmapHeight >= height) return; if (bitmapWidth < width) bitmapWidth = width; if (bitmapHeight < height) bitmapHeight = height; Bitmap newBitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888); Canvas newCanvas = new Canvas(); newCanvas.setBitmap(newBitmap); if (mBitmap != null) newCanvas.drawBitmap(mBitmap, 0, 0, null); mBitmap = newBitmap; mCanvas = newCanvas; } private void createFakeMotionEvents() { MotionEvent downEvent = MotionEvent.obtain(SystemClock.uptimeMillis(),SystemClock.uptimeMillis()+100, MotionEvent.ACTION_DOWN, 1f, 1f ,0); MotionEvent upEvent = MotionEvent.obtain(SystemClock.uptimeMillis(),SystemClock.uptimeMillis()+100, MotionEvent.ACTION_UP, 1f, 1f ,0); onTouchEvent(downEvent); onTouchEvent(upEvent); } @Override protected void onDraw(Canvas canvas) { canvas.drawColor(Color.BLACK); canvas.drawBitmap(mBitmap, 0, 0, mPaint); canvas.drawPath(mPath, mPaint); } @Override public boolean onTouchEvent(MotionEvent event) { float x = event.getX(); float y = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: touchDown(x, y); break; case MotionEvent.ACTION_MOVE: touchMove(x, y); break; case MotionEvent.ACTION_UP: touchUp(); break; } invalidate(); return true; } /**---------------------------------------------------------- * Private methods **---------------------------------------------------------*/ private void touchDown(float x, float y) { mPath.reset(); mPath.moveTo(x, y); curX = x; curY = y; } private void touchMove(float x, float y) { float dx = Math.abs(x - curX); float dy = Math.abs(y - curY); if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) { mPath.quadTo(curX, curY, (x + curX)/2, (y + curY)/2); curX = x; curY = y; } } private void touchUp() { mPath.lineTo(curX, curY); if (mCanvas == null) { mCanvas = new Canvas(); mCanvas.setBitmap(mBitmap); } mCanvas.drawPath(mPath, mPaint); mPath.reset(); } } 

然后,在你的XML中使用这个类: <com.example.myapp.gui.views.SignatureView .../>为了得到绘制的签名,使用这个: Bitmap bmp = ((SignatureView)findViewById(R.id.signatureview)).getImage();

你最终可以用这个代码保存位图:

 public void saveBitmap(Bitmap bmp) { try { String root = Environment.getExternalStorageDirectory().getAbsolutePath() + "/"; String filepath = root + "signature.jpg"; FileOutputStream fos = new FileOutputStream(filepath); bmp.compress(CompressFormat.JPEG, 100, fos); fos.flush(); fos.close(); } catch(Exception e) { Log.e("Could not save", e.getMessage()); e.printStackTrace(); } } 

这将把签名保存在你的SD卡的根目录中,如signature.jpeg。 对于写作部分,请确保在清单中具有该权限: <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

希望这个代码可以帮助你:)

esign_main.xml

 <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <android.gesture.GestureOverlayView android:id="@+id/signaturePad" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="5" android:background="@android:color/white" android:clickable="false" android:eventsInterceptionEnabled="true" android:fadeEnabled="false" android:gestureColor="#0000ff" android:gestureStrokeLengthThreshold="0.1" android:gestureStrokeType="multiple" android:longClickable="false" android:orientation="vertical" android:uncertainGestureColor="#000000" android:splitMotionEvents="true" android:fadeOffset="10000000"> </android.gesture.GestureOverlayView> <RelativeLayout android:id="@+id/rellay_esign_donebutton" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingBottom="10dp" > <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:gravity="center" > <Button android:id="@+id/DoneButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Done" /> <Button android:id="@+id/ClearButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Clear" /> </LinearLayout> </RelativeLayout> </LinearLayout> 

Esignature.java

 public class Esignature extends Activity { GestureOverlayView gestureView; String path; File file; Bitmap bitmap; public boolean gestureTouch=false; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.esign_main); Button donebutton = (Button) findViewById(R.id.DoneButton); donebutton.setText("Done"); Button clearButton = (Button) findViewById(R.id.ClearButton); clearButton.setText("Clear"); path=Environment.getExternalStorageDirectory()+"/signature.png"; file = new File(path); file.delete(); gestureView = (GestureOverlayView) findViewById(R.id.signaturePad); gestureView.setDrawingCacheEnabled(true); gestureView.setAlwaysDrawnWithCacheEnabled(true); gestureView.setHapticFeedbackEnabled(false); gestureView.cancelLongPress(); gestureView.cancelClearAnimation(); gestureView.addOnGestureListener(new OnGestureListener() { @Override public void onGesture(GestureOverlayView arg0, MotionEvent arg1) { // TODO Auto-generated method stub } @Override public void onGestureCancelled(GestureOverlayView arg0, MotionEvent arg1) { // TODO Auto-generated method stub } @Override public void onGestureEnded(GestureOverlayView arg0, MotionEvent arg1) { // TODO Auto-generated method stub } @Override public void onGestureStarted(GestureOverlayView arg0, MotionEvent arg1) { // TODO Auto-generated method stub if (arg1.getAction()==MotionEvent.ACTION_MOVE){ gestureTouch=false; } else { gestureTouch=true; } }}); donebutton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub try { bitmap = Bitmap.createBitmap(gestureView.getDrawingCache()); file.createNewFile(); FileOutputStream fos = new FileOutputStream(file); fos = new FileOutputStream(file); // compress to specified format (PNG), quality - which is // ignored for PNG, and out stream bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos); fos.close(); } catch (Exception e) { e.printStackTrace(); } if(gestureTouch==false) { setResult(0); finish(); } else { setResult(1); finish(); } } }); clearButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // TODO Auto-generated method stub gestureView.invalidate(); gestureView.clear(true); gestureView.clearAnimation(); gestureView.cancelClearAnimation(); } }); } } 

这可以在Gestureoverlay的帮助下完成。 这在APIDemos中得到了certificate。 以下链接必须有帮助:

电子签名

对于白色背景的JPG文件:

 gestureView.setDrawingCacheBackgroundColor(Color.WHITE); 

 bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos); 

使用Harshal Benake解决scheme。