无法将图像保存在指定的文件位置

Question

package com.ammu; 

import java.io.File; 
import java.lang.reflect.Field; 

import android.app.Activity; 
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.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.TextView; 

public class camera extends Activity { 
    /** Called when the activity is first created. */ 

    Button b1; 
    TextView t1; 
    ImageView im; 
    protected String path; 
    protected boolean taken; 
    protected final static String photo_taken="taken"; 
      public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     im=(ImageView)findViewById(R.id.img); 
     b1=(Button)findViewById(R.id.but); 
     t1=(TextView)findViewById(R.id.txt); 
     b1.setOnClickListener(new ButtonClickHandler()); 
     path=Environment.getExternalStorageDirectory()+"img/makemachineeg.jpeg"; 
      } 
     public class ButtonClickHandler implements View.OnClickListener{ 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       startCameraActivity(); 
      } 

     } 
     public void startCameraActivity() { 
      // TODO Auto-generated method stub 
      File file=new File(path); 
      Uri output=Uri.fromFile(file); 
      Intent intent=new Intent(MediaStore.ACTION_IMAGE_CAPTURE); 
      intent.putExtra(MediaStore.EXTRA_OUTPUT,output); 
      startActivityForResult(intent,0); 


     } 

     public void onActivityResult(int requestcode,Intent data){ 
      //Log.i("MakeMachine","resultcode"); 
      Log.i("MakeMachine","resultcode:"+requestcode); 
      switch(requestcode){ 
      case 0: 
        Log.i("makeMachine","Usercancelled"); 
        break; 
      case -1: 
        onPhotoTaken(); 
        break; 
      } 
     } 

     private void onPhotoTaken() { 
      // TODO Auto-generated method stub 
      taken=true; 
      BitmapFactory.Options option=new BitmapFactory.Options(); 
      option.inSampleSize=4; 
      Bitmap bitmap=BitmapFactory.decodeFile(path,option); 
      im.setImageBitmap(bitmap); 
      t1.setVisibility(View.GONE); 

     } 
     protected void onSaveStateInstance(Bundle outstate){ 
      outstate.putBoolean(camera.photo_taken,taken); 
      } 

     protected void onRestoreStateInstance(Bundle savedInstanceState){ 
      Log.i("MakeMachine","onRestoreInstanceState()"); 
      if(savedInstanceState.getBoolean(camera.photo_taken,taken)){ 
       onPhotoTaken(); 
      } 
      } 


} 

Answer 1

你有没有在android manifest文件中给出权限？

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />