解决通过Intent调用系统拍照程序，返回图片太小的问题[android]

转载自：http://zjf1428.iteye.com/blog/919162

以下的代码可以调用系统的拍照程序， 

Intent it = newIntent("android.media.action.IMAGE_CAPTURE"); 
startActivityForResult(it, Activity.DEFAULT_KEYS_DIALER); 
按下拍照键后，会返回到你的activity，所以你的activity要在onActivityResult方法里加一个处理， 

protectedvoidonActivityResult(intrequestCode, intresultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     try{ 
         Bundle extras = data.getExtras(); 
         Bitmap b = (Bitmap) extras.get("data"); 
         take = b; 
         ImageView img = (ImageView)findViewById(R.id.image); 
         img.setImageBitmap(take); 
     }catch(Exception e){ 
     } 
} 
但是这样你会发现这个bitmap尺寸太小了。明显是被压缩过了，要像返回未被压缩的照片，那么你要给调用系统拍照程序intent加上参数，指定图片输出的位置。 

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Intent it = newIntent("android.media.action.IMAGE_CAPTURE"); 
it.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(newFile(F.SD_CARD_TEMP_PHOTO_PATH))); 
startActivityForResult(it, Activity.DEFAULT_KEYS_DIALER); 
这样就是大图片返回了。 

protectedvoidonActivityResult(intrequestCode, intresultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     try{ 
         ImageView img = (ImageView)findViewById(R.id.image); 
         take = U.ResizeBitmap(U.getBitmapForFile(F.SD_CARD_TEMP_PHOTO_PATH), 640); 
         img.setImageBitmap(take); 
         imgflag = true; 
     }catch(Exception e){ 
     } 
} 
另外注意一下，返回的那个bitmap会很大，你用完以后要把它回收掉，不然你很容易内存报oom错误 

publicstaticBitmap ResizeBitmap(Bitmap bitmap, intnewWidth) { 
     intwidth = bitmap.getWidth(); 
     intheight = bitmap.getHeight(); 
     floattemp = ((float) height) / ((float) width); 
     intnewHeight = (int) ((newWidth) * temp); 
     floatscaleWidth = ((float) newWidth) / width; 
     floatscaleHeight = ((float) newHeight) / height; 
     Matrix matrix = newMatrix(); 
     // resize the bit map 
     matrix.postScale(scaleWidth, scaleHeight); 
     // matrix.postRotate(45); 
     Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true); 
     bitmap.recycle(); 
     returnresizedBitmap; 
}

完整版 


java类代码： 

 package com.android.camera;

 import java.io.File;
 import java.io.InputStreamReader;

 import com.android.R;
 import com.utils.CommonUtil;
 import com.utils.ExceptionDetail;

 import android.app.Activity;
 import android.content.Intent;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.graphics.Matrix;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Environment;
 import android.provider.MediaStore;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.ImageView;

 /**
  * 调用系统相机拍照保存图片并浏览图片
  *
  */
 public class CameraTest8 extends Activity implements OnClickListener{

     private String PHOTO_FOLDER=new File(Environment.getExternalStorageDirectory(), "").getPath()+"/myAndroid/";
     private String PHOTO_NAME="";

     private ImageView imageView_pic;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         // TODO Auto-generated method stub
         super.onCreate(savedInstanceState);

         setContentView(R.layout.cameratest8);

         File file=new File(PHOTO_FOLDER);
         if (!file.exists() && !file.isDirectory()) {
             file.mkdir();
         }

         Button button_camera=(Button)findViewById(R.id.button_camera);
         button_camera.setOnClickListener(this);
         imageView_pic=(ImageView)findViewById(R.id.imageView_pic);

     }

     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         // TODO Auto-generated method stub
         super.onActivityResult(requestCode, resultCode, data);

         switch(requestCode){
         case Activity.DEFAULT_KEYS_DIALER:{
             try{
                  Bitmap take = resizeBitmap(getBitmapForFile(PHOTO_FOLDER+PHOTO_NAME), 640);
                  imageView_pic.setImageBitmap(take);
              }catch(Exception e){
                  System.out.println(ExceptionDetail.getErrorMessage(e));
              }

             break;
         }
         }
     }

     public static Bitmap resizeBitmap(Bitmap bitmap, int newWidth) {
          int width = bitmap.getWidth();
          int height = bitmap.getHeight();
          float temp = ((float) height) / ((float) width);
          int newHeight = (int) ((newWidth) * temp);
          float scaleWidth = ((float) newWidth) / width;
          float scaleHeight = ((float) newHeight) / height;
          Matrix matrix = new Matrix();
          // resize the bit map
          matrix.postScale(scaleWidth, scaleHeight);
          // matrix.postRotate(45);
          Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);
          bitmap.recycle();
          return resizedBitmap;
     }

     public static Bitmap getBitmapForFile(String filePath){
         Bitmap bitmap = BitmapFactory.decodeFile(filePath);
         return bitmap;
     }

     @Override
     public void onClick(View v) {
         switch(v.getId()){
         case R.id.button_camera:{
             PHOTO_NAME="MyPic"+CommonUtil.getCurrentTime("yyyyMMddHHmmssSSS")+".jpg";
             Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
             intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(PHOTO_FOLDER+PHOTO_NAME)));
             startActivityForResult(intent, Activity.DEFAULT_KEYS_DIALER);
             break;
         }
         }
     }


 }

布局文件代码： 

 xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent" >

     <Button
         android:id="@+id/button_camera"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentLeft="true"
         android:layout_alignParentTop="true"
         android:text="相机" />

     <ImageView
         android:id="@+id/imageView_pic"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_below="@+id/button_camera"
         android:layout_centerHorizontal="true"
         android:layout_marginTop="60dp"
         android:src="@drawable/app_panel_friendcard_icon" />

 RelativeLayout>