package com.example.fingerdraw;import java.io.FileNotFoundException;
import java.io.OutputStream;import android.app.Activity;
import android.content.ContentValues;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore.Images.Media;
import android.view.Display;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;public class MainActivity extends Activity implements OnTouchListener,OnClickListener {private ImageView image;private Paint paint;private Canvas canvas;private Bitmap bitmap;private Bitmap alterBitmap;private Button choose;private Button save;private final static int RESULT = 0;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);image = (ImageView) findViewById(R.id.image);choose = (Button) findViewById(R.id.chooseButton);save=(Button)findViewById(R.id.saveButton);/** bitmap = Bitmap.createBitmap(getWindowManager().getDefaultDisplay()* .getWidth(), getWindowManager().getDefaultDisplay().getHeight(),* Bitmap.Config.ARGB_8888); canvas = new Canvas(bitmap);// 画板 paint =* new Paint();// 画刷 paint.setColor(Color.BLUE);* image.setImageBitmap(bitmap);*/image.setOnTouchListener(this);choose.setOnClickListener(this);save.setOnClickListener(this);}private float downx = 0;private float downy = 0;private float upx = 0;private float upy = 0;public boolean onTouch(View v, MotionEvent event) {int action = event.getAction();switch (action) {case MotionEvent.ACTION_DOWN:downx = event.getX();downy = event.getY();break;case MotionEvent.ACTION_MOVE:// 路径画板upx = event.getX();upy = event.getY();canvas.drawLine(downx, downy, upx, upy, paint);image.invalidate();downx = upx;downy = upy;break;case MotionEvent.ACTION_UP:// 直线画板
upx = event.getX();upy = event.getY();canvas.drawLine(downx, downy, upx, upy, paint);image.invalidate();// 刷新break;default:break;}return true;}public void onClick(View arg0) {if(arg0==choose){Intent intent = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);startActivityForResult(intent, RESULT);}else if(arg0==save){//保存画好的图片if(alterBitmap!=null){try {Uri imageUri=getContentResolver().insert(Media.EXTERNAL_CONTENT_URI, new ContentValues());OutputStream outputStream=getContentResolver().openOutputStream(imageUri);alterBitmap.compress(CompressFormat.PNG, 90, outputStream);Toast.makeText(getApplicationContext(), "save!", Toast.LENGTH_SHORT).show();} catch (FileNotFoundException e) {e.printStackTrace();}}}}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {// TODO Auto-generated method stubsuper.onActivityResult(requestCode, resultCode, data);if (resultCode == RESULT_OK) {Uri imageFileUri = data.getData();Display display = getWindowManager().getDefaultDisplay();float dw = display.getWidth();float dh = display.getHeight();try {BitmapFactory.Options options = new BitmapFactory.Options();options.inJustDecodeBounds = true;bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, options);int heightRatio = (int) Math.ceil(options.outHeight / dh);int widthRatio = (int) Math.ceil(options.outWidth / dw);if (heightRatio > 1 && widthRatio > 1) {if (heightRatio > widthRatio) {options.inSampleSize = heightRatio;} else {options.inSampleSize = widthRatio;}}options.inJustDecodeBounds = false;bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, options);alterBitmap = Bitmap.createBitmap(bitmap.getWidth(),bitmap.getHeight(), bitmap.getConfig());canvas = new Canvas(alterBitmap);paint = new Paint();paint.setColor(Color.GREEN);paint.setStrokeWidth(10);Matrix matrix = new Matrix();canvas.drawBitmap(bitmap, matrix, paint);image.setImageBitmap(alterBitmap);image.setOnTouchListener(this);} catch (FileNotFoundException e) {e.printStackTrace();}}}}