android图像编辑和处理（一）

1.使用内置Gallery应用程序选择图像：

</pre><pre name="code" class="java">package com.example.testphotoedit;import java.io.FileNotFoundException;import android.app.Activity;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.Paint;import android.net.Uri;import android.os.Bundle;import android.view.Display;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ImageView;public class MainActivity extends Activity implements OnClickListener {private ImageView chosenImageView,copyPicture;private Button choosePicture;private Uri imageFileUri;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.fragment_main);choosePicture = (Button) findViewById(R.id.button_chose);chosenImageView = (ImageView) findViewById(R.id.chose_picture);copyPicture=(ImageView) findViewById(R.id.copy_picture);choosePicture.setOnClickListener(this);}@Overridepublic void onClick(View v) {// TODO Auto-generated method stubif (v.getId() == R.id.button_chose) {Intent chooseIntent = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);//启动Gallery应用程序startActivityForResult(chooseIntent, 0);}}

/* (non-Javadoc) * @see android.app.Activity#onActivityResult(int, int, android.content.Intent) *  * 在返回的意图数据中，返回选择的图像的URI */@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {// TODO Auto-generated method stubsuper.onActivityResult(requestCode, resultCode, data);if (resultCode == RESULT_OK) {imageFileUri = data.getData();Display currentDisply = getWindowManager().getDefaultDisplay();int dw = currentDisply.getWidth() / 2 - 100;int dh = currentDisply.getHeight() / 2 - 100；

<span style="font-family: Arial, Helvetica, sans-serif;">try {</span>

BitmapFactory.Options bmpFactory = new BitmapFactory.Options();bmpFactory.inJustDecodeBounds = true;//加载图像的尺寸而非图像本身Bitmap bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactory);int heightRatio = (int) Math.ceil(bmpFactory.outHeight/ (float) dh);int widthRatio = (int) Math.ceil(bmpFactory.outWidth/ (float) dw);if (heightRatio > 1 && widthRatio > 1) {if (heightRatio > widthRatio) {bmpFactory.inSampleSize = heightRatio;} else {bmpFactory.inSampleSize = widthRatio;}}bmpFactory.inJustDecodeBounds = false;//加载真实的图像bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactory);chosenImageView.setImageBitmap(bmp);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}}

2.在位图上绘制位图

Bitmap alteredBitmap = Bitmap.createBitmap(bmp.getWidth(),bmp.getWidth(), bmp.getConfig());Canvas canvas=new Canvas(alteredBitmap);Paint  paint=new Paint();canvas.drawBitmap(bmp, 0,0, paint);copyPicture.setImageBitmap(alteredBitmap);

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context="com.example.testphotoedit.MainActivity$PlaceholderFragment" >    <Button         android:id="@+id/button_chose"        android:layout_width="120dp"        android:layout_height="60dp"        android:text="选择图片"/>        <ImageView        android:id="@+id/chose_picture"        android:layout_below="@+id/button_chose"        android:layout_width="wrap_content"        android:layout_height="wrap_content" />     <ImageView        android:id="@+id/copy_picture"        android:layout_below="@+id/chose_picture"        android:layout_width="wrap_content"        android:layout_height="wrap_content" /></RelativeLayout>

注：有什么不懂的可以留言。。