简单的画笔绘制功能实现

package com.Lee.DrawDemo; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.Paint.Style; import android.os.Bundle; import android.os.Environment; import android.util.Log; 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 DrawDemoActivity extends Activity implements OnTouchListener, OnClickListener { Bitmap bitmap; ImageView imageView; float upX; float upY; float downX; float downY; int dw = 0; int dh = 0; String TAG = "DrawDemoActivity"; Canvas canvas; Paint paint; ImageView mImageView; Bitmap myBitmap; Matrix matrix; Button btn1, btn2; Context context = DrawDemoActivity.this; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); btn1 = (Button) findViewById(R.id.btn1); btn2 = (Button) findViewById(R.id.btn2); mImageView = (ImageView) findViewById(R.id.bg_Image); dw = getWindowManager().getDefaultDisplay().getWidth(); dh = getWindowManager().getDefaultDisplay().getHeight(); paint = new Paint(); paint.setColor(Color.BLACK); paint.setStrokeWidth(5); paint.setStyle(Style.FILL_AND_STROKE); matrix = new Matrix(); myBitmap = Bitmap.createBitmap(dw -100, dh-100, Config.ARGB_8888); canvas = new Canvas(myBitmap); canvas.drawColor(Color.GRAY); mImageView.setImageBitmap(myBitmap); bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher); mImageView.setOnTouchListener(this);// 设置监听 btn1.setOnClickListener(this); btn2.setOnClickListener(this); } @Override public void onClick(View v) { // TODO Auto-generated method stub Log.e(TAG, "onClick"); switch (v.getId()) { case R.id.btn2:// 重绘 myBitmap = Bitmap.createBitmap(dw+200, dh+200, Config.ARGB_8888); canvas = new Canvas(myBitmap); canvas.drawColor(Color.RED); mImageView.setImageBitmap(myBitmap); Log.e(TAG, "Clear"); break; case R.id.btn1:// 保存已经涂鸦过的图片 if (null != myBitmap) { String rootpath = Environment.getExternalStorageDirectory() .getPath(); File dir = new File(rootpath + "/Draw/");// 输出路径 if (!dir.exists()) { Log.e(TAG, "dir.exists"); dir.mkdirs(); } File file = new File(rootpath + "/Draw/Test.jpg");// 输出路径 try { file.createNewFile(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); Log.e(TAG, "createNewFile" + e.toString()); } FileOutputStream out = null; try { out = new FileOutputStream(file); } catch (FileNotFoundException e1) { // TODO Auto-generated catch block e1.printStackTrace(); Log.e(TAG, "FileNotFoundException" + e1.toString()); } // 设置输出流 myBitmap.compress(Bitmap.CompressFormat.JPEG, 100, out); Toast.makeText(this, "已保存"+file.toString(), Toast.LENGTH_SHORT).show(); try { out.flush(); out.close(); } catch (IOException e1) { // TODO Auto-generated catch block e1.printStackTrace(); Log.e(TAG, "IOException" + e1.toString()); } } Log.e(TAG, "Save"); break; } } @Override public boolean onTouch(View v, MotionEvent event) { // TODO Auto-generated method stub switch (event.getAction()) { case MotionEvent.ACTION_UP: canvas.drawBitmap(bitmap, upX, upY, paint); mImageView.invalidate(); break; 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); mImageView.invalidate(); downX = upX; downY = upY; break; case MotionEvent.ACTION_CANCEL: break; } return true; } }