问题
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Hi I am a PHP developer I want to do a simple thing - I want to draw something drawn on a blank page on an Android Phone (with a finger with a largeish "emulated pen nib") and store the bitmap as a jpeg on a server by http post.
Here is what I have so far but this is taken from a tutorial that is involved with writing sprites for a game.. And I cant' adapt it
package com.my.example;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;
public class DrawCapture extends Activity implements OnTouchListener{
OurView v;
Bitmap ball;
float x,y;
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.draw_capture);
v = new OurView(this);
v.setOnTouchListener(this);
ball = BitmapFactory.decodeResource(getResources(), R.drawable.blueball);
x = y = 0;
setContentView(v);
}
@Override
protected void onPause(){
super.onPause();
v.pause();
}
protected void onResume(){
super.onResume();
v.resume();
}
public class OurView extends SurfaceView implements Runnable{
Thread t = null;
SurfaceHolder holder;
boolean isItOK = false;
public OurView(Context context) {
super(context);
holder = getHolder();
}
public void run() {
while (isItOK == true){
try {
Thread.sleep(50);
} catch (InterruptedException e) {
e.printStackTrace();
}
//perform canvas drawing
if (!holder.getSurface().isValid()){
continue;
}
Canvas c = holder.lockCanvas();
onDraw(c);
holder.unlockCanvasAndPost(c);
}
}
public void onDraw(Canvas c){
c.drawARGB(255, 210, 210, 210);
c.drawBitmap(ball, x - (ball.getWidth()/2), y - (ball.getHeight()/2), null);
}
public void pause(){
isItOK = false;
while(true){
try{
t.join();
} catch(InterruptedException e){
e.printStackTrace();
}
break;
}
t = null;
}
public void resume(){
isItOK = true;
t = new Thread(this);
t.start();
}
}
public boolean onTouch(View v, MotionEvent me){
switch (me.getAction()){
case MotionEvent.ACTION_DOWN :
x = me.getX();
y = me.getY();
break;
case MotionEvent.ACTION_UP :
x = me.getX();
y = me.getY();
break;
case MotionEvent.ACTION_MOVE :
x = me.getX();
y = me.getY();
break;
}
return true;
}
}
and here is the XML
<?xml version="1.0" encoding="utf-8"?>
<SurfaceView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
</SurfaceView>
Can someone please help me? I feel I am close - I use the blueball as a pen nib I just want to "save" this and possibly I'll need to have a button (or menu) on the XML page to do this ? I know it's a bit of a beg but there are a lot of people online asking how to draw with your finger and save something to the "cloud" if people could respond with examples of the code (not references) I promise I will compile this into a proper tutorial piece of code for the eventual benefit of all. Including the PHP server side code that I already am really happy with.
回答1:
You can try to use the Gesture Object proposed by Google, try to execute my following code :
Activity1 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"
android:background="#FFFFFF" >
<android.gesture.GestureOverlayView
android:id="@+id/gestures"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:fadeEnabled="false"
android:fadeOffset="5000000000"
android:gestureColor="#000000"
android:gestureStrokeType="multiple"
android:gestureStrokeWidth="1"
android:uncertainGestureColor="#000000"
android:layout_above="@+id/save_button" />
<Button
android:id="@id/save_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="20sp"
android:paddingLeft="20sp"
android:paddingRight="20sp"
android:text="Save"
android:textSize="22sp" />
</RelativeLayout>
Activity1 java :
package com.testandroidproject;
import java.io.ByteArrayOutputStream;
import android.app.Activity;
import android.content.Intent;
import android.gesture.GestureOverlayView;
import android.graphics.Bitmap;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class Activity1 extends Activity {
private Button button_save;
private GestureOverlayView gesture;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gesture = (GestureOverlayView) findViewById(R.id.gestures);
button_save = (Button) findViewById(R.id.save_button);
button_save.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
try {
Bitmap gestureImg = gesture.getGesture().toBitmap(100, 100,
8, Color.BLACK);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
gestureImg.compress(Bitmap.CompressFormat.PNG, 100, bos);
byte[] bArray = bos.toByteArray();
Intent intent = new Intent(Activity1.this, Activity2.class);
intent.putExtra("draw", bArray);
startActivity(intent);
} catch (Exception e) {
e.printStackTrace();
Toast.makeText(Activity1.this, "No draw on the string",
3000).show();
}
}
});
}
}
Activity2 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:background="#FFFFFF"
android:orientation="vertical" >
<ImageView
android:id="@+id/image_saved"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal" />
</LinearLayout>
Activity2 java :
package com.testandroidproject;
import java.io.ByteArrayInputStream;
import android.app.Activity;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;
public class Activity2 extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.display_image);
ImageView image = (ImageView) findViewById(R.id.image_saved);
ByteArrayInputStream imageStreamClient = new ByteArrayInputStream(
getIntent().getExtras().getByteArray("draw"));
image.setImageBitmap(BitmapFactory.decodeStream(imageStreamClient));
}
}
Hope you will find this helpful.
回答2:
I'm not sure what part of the "save" you are trying to accomplish, but I'll assume you're asking how to store what you've drawn on the canvas to a bitmap.
First, make yourself a bitmap to draw into. Say, canvasBitmap. Then:
c.setBitmap(canvasBitmap);
This will store everything that has been drawn into 'canvasBitmap.' Then, when the user presses a button to save:
savedBitmap = Bitmap.copy(canvasBitmap.getConfig(), true);
Now, take savedBitmap and fire it off into the cloud. Hope that helps.
来源：https://stackoverflow.com/questions/11631700/how-to-draw-something-with-your-finger-in-an-android-app-and-save-it-to-the