在 Android 上的 Rhodes 中将签名图片保存到文件中
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【中文标题】在 Android 上的 Rhodes 中将签名图片保存到文件中【英文标题】：Save a picture of a signature to a file in Rhodes on Android 【发布时间】：2012-02-19 08:08:08 【问题描述】：我正在尝试使用针对 android 选项卡的 Rhodes 实现签名捕获。我设法拿到画布并在上面涂鸦。但是我无法将签名保存在所需的位置。 signature_uri 采用默认位置为db/db-files/Image-XXXXXX.png。
这是示例中的代码：
def signature_callback
if @params['status'] == 'ok'
#create signature record in the DB
signature = SignatureUtil.new('signature_uri'=>@params['signature_uri'])
signature.save
puts "new Signature object: " + signature.inspect
end
在我得到的控制台中：
APP| RHO serve: /app/Settings/signature_callback
I/APP ( 801): I 01/26/2012 11:36:20:236 0000032e APP| Params: "status"=>"ok", "signature_uri"=>"db/db-files/Image_20120126113618375.png", "rho_callback"=>"1"
I/APP ( 801): I 01/26/2012 11:36:20:238 0000032e APP| *******************ok****************
I/APP ( 801): I 01/26/2012 11:36:20:238 0000032e APP| %%%%%%%%%%%%%%%%%db/db-files/Image_20120126113618375.png%%%%%%%%%%%
I/APP ( 801): I 01/26/2012 11:36:20:239 0000032e APP| App error: can't convert Symbol into Integer
I/APP ( 801): lib/rhom/rhom_object_factory.rb:67:in `[]'
I/APP ( 801): lib/rhom/rhom_object_factory.rb:67:in `initialize'
I/APP ( 801): apps/app/Settings/controller.rb:34:in `new'
I/APP ( 801): apps/app/Settings/controller.rb:34:in `signature_callback'
I/APP ( 801): lib/rho/rhocontroller.rb:91:in `serve'
I/APP ( 801): lib/rho/rhoapplication.rb:209:in `serve'
I/APP ( 801): lib/rho/rho.rb:822:in `serve'
I/APP ( 801): E 01/26/2012 11:36:20:248 00000321 Net| Request failed. HTTP Code: 500 returned. HTTP Response: <html>
I/APP ( 801): <head>
I/APP ( 801): <meta name="viewport" content="width=320"/>
I/APP ( 801): </head>
I/APP ( 801): <body>
I/APP ( 801): <h2>Server Error</h2>
I/APP ( 801): <p>
I/APP ( 801): Error: can't convert Symbol into Integer<br/>Trace: <br/
现在我想将它保存在所需的位置，而不是这个数据库存储。请分享您的观点。
【问题讨论】：
你能给我们看看痕迹吗？其他人：请阅读问题。他已经捕获了签名，但他想和罗德一起保存它。这是真正的问题，不是“如何在 Android 上捕获签名”。 【参考方案1】：只需尝试在签名 uri 中传递 sd 卡位置。 请注意在 manifest 中给予 sd 卡读写权限。
否则
将签名文件从内部包复制到所需位置，但这是重复工作。
【讨论】：
感谢 Manish 的回复，并为迟到的回复道歉。试过了，但没有运气。【参考方案2】：您是否查看过此页面：http://docs.rhomobile.com/rhodes/device-caps#file-system-access？在我看来，您需要将图像保存到数据库并使用 Rho::RhoApplication::get_blob_path(image.image_uri) 方法打开文件。然后您应该能够使用文件系统 API 创建一个新文件并将图像的内容写入您选择的任何位置。
【讨论】：
这与我们在项目中所做的非常接近。基本上 signature_uri 返回已保存图像的位置（我不知何故无法访问）。我们将此位置作为图像源推送到 Web 服务并在数据库中创建记录。通过正在存储的文件的大小验证正在保存的图像。笔画数与图像大小成正比。【参考方案3】：下面的代码可能对你有用
import java.io.File;
import java.io.FileOutputStream;
import java.util.Calendar;
import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore.Images;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.view.Window;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.Toast;
public class CaptureSignature extends Activity
LinearLayout mContent;
signature mSignature;
Button mClear, mGetSign, mCancel;
public static String tempDir;
public int count = 1;
public String current = null;
private Bitmap mBitmap;
View mView;
File mypath;
private String uniqueId;
private EditText yourName;
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.signature);
tempDir = Environment.getExternalStorageDirectory() + "/" + getResources().getString(R.string.external_dir) + "/";
ContextWrapper cw = new ContextWrapper(getApplicationContext());
File directory = cw.getDir(getResources().getString(R.string.external_dir), Context.MODE_PRIVATE);
prepareDirectory();
uniqueId = getTodaysDate() + "_" + getCurrentTime() + "_" + Math.random();
current = uniqueId + ".png";
mypath= new File(directory,current);
mContent = (LinearLayout) findViewById(R.id.linearLayout);
mSignature = new signature(this, null);
mSignature.setBackgroundColor(Color.WHITE);
mContent.addView(mSignature, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
mClear = (Button)findViewById(R.id.clear);
mGetSign = (Button)findViewById(R.id.getsign);
mGetSign.setEnabled(false);
mCancel = (Button)findViewById(R.id.cancel);
mView = mContent;
yourName = (EditText) findViewById(R.id.yourName);
mClear.setOnClickListener(new OnClickListener()
public void onClick(View v)
Log.v("log_tag", "Panel Cleared");
mSignature.clear();
mGetSign.setEnabled(false);
);
mGetSign.setOnClickListener(new OnClickListener()
public void onClick(View v)
Log.v("log_tag", "Panel Saved");
boolean error = captureSignature();
if(!error)
mView.setDrawingCacheEnabled(true);
mSignature.save(mView);
Bundle b = new Bundle();
b.putString("status", "done");
Intent intent = new Intent();
intent.putExtras(b);
setResult(RESULT_OK,intent);
finish();
);
mCancel.setOnClickListener(new OnClickListener()
public void onClick(View v)
Log.v("log_tag", "Panel Canceled");
Bundle b = new Bundle();
b.putString("status", "cancel");
Intent intent = new Intent();
intent.putExtras(b);
setResult(RESULT_OK,intent);
finish();
);
@Override
protected void onDestroy()
Log.w("GetSignature", "onDestory");
super.onDestroy();
private boolean captureSignature()
boolean error = false;
String errorMessage = "";
if(yourName.getText().toString().equalsIgnoreCase(""))
errorMessage = errorMessage + "Please enter your Name\n";
error = true;
if(error)
Toast toast = Toast.makeText(this, errorMessage, Toast.LENGTH_SHORT);
toast.setGravity(Gravity.TOP, 105, 50);
toast.show();
return error;
private String getTodaysDate()
final Calendar c = Calendar.getInstance();
int todaysDate = (c.get(Calendar.YEAR) * 10000) +
((c.get(Calendar.MONTH) + 1) * 100) +
(c.get(Calendar.DAY_OF_MONTH));
Log.w("DATE:",String.valueOf(todaysDate));
return(String.valueOf(todaysDate));
private String getCurrentTime()
final Calendar c = Calendar.getInstance();
int currentTime = (c.get(Calendar.HOUR_OF_DAY) * 10000) +
(c.get(Calendar.MINUTE) * 100) +
(c.get(Calendar.SECOND));
Log.w("TIME:",String.valueOf(currentTime));
return(String.valueOf(currentTime));
private boolean prepareDirectory()
try
if (makedirs())
return true;
else
return false;
catch (Exception e)
e.printStackTrace();
Toast.makeText(this, "Could not initiate File System.. Is Sdcard mounted properly?", 1000).show();
return false;
private boolean makedirs()
File tempdir = new File(tempDir);
if (!tempdir.exists())
tempdir.mkdirs();
if (tempdir.isDirectory())
File[] files = tempdir.listFiles();
for (File file : files)
if (!file.delete())
System.out.println("Failed to delete " + file);
return (tempdir.isDirectory());
public class signature extends View
private static final float STROKE_WIDTH = 5f;
private static final float HALF_STROKE_WIDTH = STROKE_WIDTH / 2;
private Paint paint = new Paint();
private Path path = new Path();
private float lastTouchX;
private float lastTouchY;
private final RectF dirtyRect = new RectF();
public signature(Context context, AttributeSet attrs)
super(context, attrs);
paint.setAntiAlias(true);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
public void save(View v)
Log.v("log_tag", "Width: " + v.getWidth());
Log.v("log_tag", "Height: " + v.getHeight());
if(mBitmap == null)
mBitmap = Bitmap.createBitmap (mContent.getWidth(), mContent.getHeight(), Bitmap.Config.RGB_565);;
Canvas canvas = new Canvas(mBitmap);
try
FileOutputStream mFileOutStream = new FileOutputStream(mypath);
v.draw(canvas);
mBitmap.compress(Bitmap.CompressFormat.PNG, 90, mFileOutStream);
mFileOutStream.flush();
mFileOutStream.close();
String url = Images.Media.insertImage(getContentResolver(), mBitmap, "title", null);
Log.v("log_tag","url: " + url);
//In case you want to delete the file
//boolean deleted = mypath.delete();
//Log.v("log_tag","deleted: " + mypath.toString() + deleted);
//If you want to convert the image to string use base64 converter
catch(Exception e)
Log.v("log_tag", e.toString());
public void clear()
path.reset();
invalidate();
@Override
protected void onDraw(Canvas canvas)
canvas.drawPath(path, paint);
@Override
public boolean onTouchEvent(MotionEvent event)
float eventX = event.getX();
float eventY = event.getY();
mGetSign.setEnabled(true);
switch (event.getAction())
case MotionEvent.ACTION_DOWN:
path.moveTo(eventX, eventY);
lastTouchX = eventX;
lastTouchY = eventY;
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
resetDirtyRect(eventX, eventY);
int historySize = event.getHistorySize();
for (int i = 0; i < historySize; i++)
float historicalX = event.getHistoricalX(i);
float historicalY = event.getHistoricalY(i);
expandDirtyRect(historicalX, historicalY);
path.lineTo(historicalX, historicalY);
path.lineTo(eventX, eventY);
break;
default:
debug("Ignored touch event: " + event.toString());
return false;
invalidate((int) (dirtyRect.left - HALF_STROKE_WIDTH),
(int) (dirtyRect.top - HALF_STROKE_WIDTH),
(int) (dirtyRect.right + HALF_STROKE_WIDTH),
(int) (dirtyRect.bottom + HALF_STROKE_WIDTH));
lastTouchX = eventX;
lastTouchY = eventY;
return true;
private void debug(String string)
private void expandDirtyRect(float historicalX, float historicalY)
if (historicalX < dirtyRect.left)
dirtyRect.left = historicalX;
else if (historicalX > dirtyRect.right)
dirtyRect.right = historicalX;
if (historicalY < dirtyRect.top)
dirtyRect.top = historicalY;
else if (historicalY > dirtyRect.bottom)
dirtyRect.bottom = historicalY;
private void resetDirtyRect(float eventX, float eventY)
dirtyRect.left = Math.min(lastTouchX, eventX);
dirtyRect.right = Math.max(lastTouchX, eventX);
dirtyRect.top = Math.min(lastTouchY, eventY);
dirtyRect.bottom = Math.max(lastTouchY, eventY);
【讨论】：
不是在寻找活动类/android 代码片段好友。还是谢谢以上是关于在 Android 上的 Rhodes 中将签名图片保存到文件中的主要内容，如果未能解决你的问题，请参考以下文章
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