我正在创建一个在文件图像上创建签名的应用程序。在这里，我将图像文件从存储卡加载到应用程序，并使用Canvas Paint可以通过绘图手动创建签名。
此处的问题是客户登录特定位置的应用程序要求。我的代码允许客户可以在客户想要的任何地方登录，例如在窗户上绘画。现在，我只想在特定区域签名......帮助我......
这是我的代码
Main.java
public class Longvan extends Activity implements OnClickListener, OnTouchListener {
ImageView choosenImageView;
Button choosePicture;
Button savePicture;
Bitmap bmp;
Bitmap alteredBitmap;
Canvas canvas;
Paint paint;
Matrix matrix;
float downx = 0;
float downy = 0;
float upx = 0;
float upy = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_longvan);
int currentOrientation = getResources().getConfiguration().orientation;
if (currentOrientation == Configuration.ORIENTATION_LANDSCAPE) {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
}
else {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
}
choosenImageView = (ImageView) this.findViewById(R.id.ChoosenImageView);
choosePicture = (Button) this.findViewById(R.id.ChoosePictureButton);
savePicture = (Button) this.findViewById(R.id.SavePictureButton);
savePicture.setOnClickListener(this);
choosePicture.setOnClickListener(this);
choosenImageView.setOnTouchListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_longvan, menu);
return true;
}
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
downx = event.getX();
downy = event.getY();
break;
case MotionEvent.ACTION_MOVE:
upx = event.getX();
upy = event.getY();
canvas.drawLine(downx, downy, upx, upy, paint);
choosenImageView.invalidate();
downx = upx;
downy = upy;
break;
case MotionEvent.ACTION_UP:
upx = event.getX();
upy = event.getY();
canvas.drawLine(downx, downy, upx, upy, paint);
choosenImageView.invalidate();
break;
case MotionEvent.ACTION_CANCEL:
break;
default:
break;
}
return true;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
if (v == choosePicture) {
Intent choosePictureIntent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(choosePictureIntent, 0);
} else if (v == savePicture) {
if (alteredBitmap != null) {
ContentValues contentValues = new ContentValues(3);
contentValues.put(Media.DISPLAY_NAME, "Draw On Me");
Uri imageFileUri = getContentResolver().insert(Media.EXTERNAL_CONTENT_URI, contentValues);
try {
OutputStream imageFileOS = getContentResolver().openOutputStream(imageFileUri);
alteredBitmap.compress(CompressFormat.JPEG, 90, imageFileOS);
Toast t = Toast.makeText(this, "Thank you! Image Saved!", Toast.LENGTH_LONG);
t.show();
} catch (Exception e) {
Log.v("EXCEPTION", e.getMessage());
}
}
}
}
protected void onActivityResult(int requestCode, int resultCode,
Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
if (resultCode == RESULT_OK) {
Uri imageFileUri = intent.getData();
try {
BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
bmpFactoryOptions.inJustDecodeBounds = true;
bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(
imageFileUri), null, bmpFactoryOptions);
bmpFactoryOptions.inJustDecodeBounds = false;
bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(
imageFileUri), null, bmpFactoryOptions);
alteredBitmap = Bitmap.createBitmap(bmp.getWidth(),bmp.getHeight(),bmp.getConfig());
canvas = new Canvas(alteredBitmap);
paint = new Paint();
paint.setColor(Color.BLUE);
paint.setStrokeWidth(2);
matrix = new Matrix();
canvas.drawBitmap(bmp, matrix, paint);
choosenImageView.setImageBitmap(alteredBitmap);
choosenImageView.setOnTouchListener(this);
} catch (Exception e) {
Log.v("ERROR", e.toString());
}
}
}
}
答案 0 :(得分：6)
用于输入签名的特定视图怎么样？这样的事情：https://github.com/CoatedMoose/CustomViews/tree/master/library/src/com/coatedmoose/customviews
然后，为Bitmap添加此setter：
public void setImage(Bitmap bitmap) {
this.mBitmap = bitmap;
this.invalidate();
}
或者，如果您不希望将应用的位图作为签名视图的一部分（将其用作背景，而不是画布），请将onDraw方法替换为：
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.TRANSPARENT);
canvas.drawBitmap(mBitmap, 0, 0, mPaint);
canvas.drawPath(mPath, mPaint);
}
然后只使用mSignatureView.setBackgroundResource(R.drawable.background);
编辑：
只需使用coatedMoose中的代码创建一个Class，并在布局XML中使用它：
<com.example.myapp.gui.views.SignatureView
android:id="@+id/signature"
android:layout_width="match_parent"
android:layout_height="80dp"/>
在代码中的某个位置，甚至作为XML属性，您可以设置背景。
编辑：signatureView类：
package me.other;
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 {
@SuppressWarnings("unused")
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.TRANSPARENT);
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.TRANSPARENT);
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();
}
}
一些随机布局XML：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.example.mysignatureviewapp.views.SignatureView
android:id="@+id/sign"
android:layout_width="match_parent"
android:layout_height="204dp">
</com.example.mysignatureviewapp.views.SignatureView>
</RelativeLayout>
在onCreate()方法中：
private SignatureView sign;
//
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.mysignatureviewlayout);
sign = (SignatureView) findViewById(R.id.sign);
sign.setBackgroundResource(R.drawable.mybackgrounddrawable);
}
//get your signature when you press, say, the back button
@Override
public void onBackPressed() {
Bitmap mySignature = sign.getImage();
//do something with bitmap
}
同时获得背景和签名：
BitmapDrawable mySignature = new BitmapDrawable(sign.getImage());
Drawable background = sign.getBackground();
LayerDrawable ld = new LayerDrawable(new Drawable[] { mySignature, background});