android读取相册照片和相机照片

  之前在读取照片的时候总是遇到一个问题，就是在照相机里读出的照片像素高，没办法放到自己定义好的imageview中，但是如果用bundle的方法读取的话，独处的像素很低，图片根本看不清，所以我决定采用把相机里的图片先存到手机的文档中，然后在文档中通过压缩的方式读取照片就ok了。压缩图片需要BitmapFactory.options

 

final BitmapFactory.Options options=new BitmapFactory.Options();options.inJustDecodeBounds=true;BitmapFactory.decodeFile(mUri.getPath(), options);options.inSampleSize=calculateInSampleSize(options, 275, 275);options.inJustDecodeBounds=false;Bitmap bitmap=BitmapFactory.decodeFile(mUri.getPath(), options);imageview.setImageBitmap(bitmap);

calculateInSampleSize是进行图片裁剪的函数。下面将会给出。

options.inJustDecodeBounds大家可以查一下它的含义就会明白怎样设true和false

public static int calculateInSampleSize(BitmapFactory.Options options,int resWidth,int resHeigth){//原始照片的高和宽final int heigth=options.outHeight;final int width=options.outWidth;    int inSampleSize=1;// 计算压缩的比例：分为宽高比例    final int heigthRatio=Math.round((float)heigth/(float)resHeigth);    final int widthRadtio=Math.round((float)width/(float)resWidth);    inSampleSize=heigthRatio<widthRadtio?heigthRatio:widthRadtio;    return inSampleSize;}

ok下面我将给出全部的代码。记得要添加相机权限在清单里。

package com.example.facedatect1;import java.io.File;import java.io.FileNotFoundException;import java.io.IOException;import java.sql.Date;import java.text.SimpleDateFormat;import java.util.Map;import android.R.id;import android.R.integer;import android.app.Activity;import android.content.ContentResolver;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.provider.MediaStore;import android.util.Log;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.Toast;public class MainActivity extends Activity {private Button picbtn;private Button cambtn;private ImageView imageview;public static final int TAKE_PIC=1;public static final int TAKE_CAM=2;private Uri mUri=null;//图片路径private String filename;//图片名称private Bitmap bit;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);imageview=(ImageView)findViewById(R.id.imageView1);picbtn=(Button)findViewById(R.id.picbtn);picbtn.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubIntent intent=new Intent();intent.setType("image/*");//使用Intent.ACTION_GET_CONTENTintent.setAction(Intent.ACTION_GET_CONTENT);/* 取得相片后返回本画面 */ startActivityForResult(intent, TAKE_PIC);}});cambtn=(Button)findViewById(R.id.camarabtn);cambtn.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stub// 先建立一个保存图片的文件，再进行拍照事件的触发SimpleDateFormat format=new SimpleDateFormat("yyyyMMddHHmmSS");Date date=new Date(System.currentTimeMillis());filename=format.format(date);//创建File对象用于存储拍照的图片 SD卡根目录                       //存储至DCIM文件夹File path=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);File outputImage=new File(path,filename+".jpg");try {                if(outputImage.exists()) {                    outputImage.delete();                }                outputImage.createNewFile();            } catch(IOException e) {                e.printStackTrace();            }//将File对象转换为Uri并启动照相程序mUri=Uri.fromFile(outputImage);Intent intent=new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);intent.putExtra(MediaStore.EXTRA_OUTPUT, mUri);//指定图片输出地址startActivityForResult(intent, TAKE_CAM);}});}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {// TODO Auto-generated method stubsuper.onActivityResult(requestCode, resultCode, data);if (resultCode != RESULT_OK) {             Toast.makeText(MainActivity.this, "照相失败"+resultCode, Toast.LENGTH_SHORT).show();            return;         }switch (requestCode) {case TAKE_PIC:    mUri=data.getData();Log.e("uri", "-------->>"+mUri);ContentResolver cr=this.getContentResolver();final BitmapFactory.Options option=new BitmapFactory.Options();option.inJustDecodeBounds=true;try {BitmapFactory.decodeStream(cr.openInputStream(mUri), null, option);} catch (FileNotFoundException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}option.inSampleSize=calculateInSampleSize(option, 275, 275);

                    //275是自己设的截图后的大小，大家可以根据自己的需求自己定义option.inJustDecodeBounds=false;try {bit = BitmapFactory.decodeStream(cr.openInputStream(mUri), null, option);imageview.setImageBitmap(bit);} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}break;case TAKE_CAM:final BitmapFactory.Options options=new BitmapFactory.Options();options.inJustDecodeBounds=true;BitmapFactory.decodeFile(mUri.getPath(), options);options.inSampleSize=calculateInSampleSize(options, 275, 275);options.inJustDecodeBounds=false;bit=BitmapFactory.decodeFile(mUri.getPath(), options);imageview.setImageBitmap(bit);break;}}public static int calculateInSampleSize(BitmapFactory.Options options,int resWidth,int resHeigth){//原始照片的高和宽final int heigth=options.outHeight;final int width=options.outWidth;    int inSampleSize=1;// 计算压缩的比例：分为宽高比例    if (heigth > resHeigth || width > resWidth) {    final int heigthRatio=Math.round((float)heigth/(float)resHeigth);    final int widthRadtio=Math.round((float)width/(float)resWidth);    inSampleSize=heigthRatio<widthRadtio?heigthRatio:widthRadtio;}    return inSampleSize;}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();if (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}}