图片画画板

这个应用只是简单的模仿windows的画画板，当然不会有那么多功能（其实那货的功能已经够少的了）。这个目的只是简单的提提里面的一些重要的函数。

package com.example.mytest;import java.io.OutputStream;import java.net.URI;import java.util.ArrayList;import java.util.List;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.impl.conn.DefaultClientConnection;import org.apache.http.message.BasicNameValuePair;import android.app.Activity;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.os.Bundle;import android.util.Log;import android.view.MotionEvent;import android.view.View;import android.view.View.OnTouchListener;import android.widget.ImageView;import android.widget.TextView;public class MainActivity extends Activity {private ImageView iv ;private Bitmap bm ;private Canvas canvas;private Paint paint;@Overrideprotected void onCreate(Bundle savedInstanceState) {// TODO Auto-generated method stubsuper.onCreate(savedInstanceState);setContentView(R.layout.activity_main);iv = (ImageView) findViewById(R.id.iv);paint = new Paint();paint.setColor(Color.BLACK);paint.setStrokeWidth(5);iv.setOnTouchListener( new OnTouchListener() {int startX = 0;int startY = 0;@Overridepublic boolean onTouch(View v, MotionEvent event) {// TODO Auto-generated method stubswitch (event.getAction()) {//手指第一次接触屏幕case MotionEvent.ACTION_DOWN:bm = Bitmap.createBitmap(iv.getWidth(), iv.getHeight(), Bitmap.Config.ARGB_8888);canvas = new Canvas(bm);canvas.drawColor(Color.WHITE);startX = (int) event.getX();startY = (int) event.getY();break;    //手指在移动case MotionEvent.ACTION_MOVE:int newX = (int) event.getX();int newY = (int) event.getY();canvas.drawLine(startX, startY, newX, newY, paint);startX = newX;startY = newY;iv.setImageBitmap(bm);break;//手指移开屏幕case MotionEvent.ACTION_UP:break;default:break;}return true;}});}}