android 选择图片(从手机照相机或手机图片)

package com.app.imagechooser;

import java.io.File;

import android.app.Activity;
import android.app.AlertDialog;

import android.content.DialogInterface;
import android.content.Intent;

import android.database.Cursor;
import android.provider.MediaStore;
import android.net.Uri;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

import android.os.Bundle;
import android.os.Environment;

import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.Button;

/**
 * This example shows how to create and handle image picker in Android.
 * 
 * @author Lorensius W. L. T <lorenz@londatiga.net>
 *
 */
public class MainActivity extends Activity {
	private Uri mImageCaptureUri;
	private ImageView mImageView;	

	private static final int PICK_FROM_CAMERA = 1;
	private static final int PICK_FROM_FILE = 2;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        final String [] items			= new String [] {"From Camera", "From SD Card"};				
		ArrayAdapter<String> adapter	= new ArrayAdapter<String> (this, android.R.layout.select_dialog_item,items);
		AlertDialog.Builder builder		= new AlertDialog.Builder(this);
	//android.R.layout.select_dialog_item 这是android内置布局	
		builder.setTitle("Select Image");
		builder.setAdapter( adapter, new DialogInterface.OnClickListener() {
			public void onClick( DialogInterface dialog, int item ) {
				if (item == 0) {
					Intent intent 	 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
					File file		 = new File(Environment.getExternalStorageDirectory(),
							   			"tmp_avatar_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
					mImageCaptureUri = Uri.fromFile(file);

					try {			
						intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);
						intent.putExtra("return-data", true);

						startActivityForResult(intent, PICK_FROM_CAMERA);
					} catch (Exception e) {
						e.printStackTrace();
					}			

					dialog.cancel();
				} else {
					Intent intent = new Intent();

	                intent.setType("image/*");
	                intent.setAction(Intent.ACTION_GET_CONTENT);

	                startActivityForResult(Intent.createChooser(intent, "Complete action using"), PICK_FROM_FILE);
				}
			}
		} );

		final AlertDialog dialog = builder.create();

		mImageView = (ImageView) findViewById(R.id.iv_pic);

		((Button) findViewById(R.id.btn_choose)).setOnClickListener(new View.OnClickListener() {			
			@Override
			public void onClick(View v) {
				dialog.show();
			}
		});
    }

    @Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
	    if (resultCode != RESULT_OK) return;

		Bitmap bitmap 	= null;
		String path		= "";

		if (requestCode == PICK_FROM_FILE) {
			mImageCaptureUri = data.getData(); 
			path = getRealPathFromURI(mImageCaptureUri); //from Gallery 

			if (path == null)
				path = mImageCaptureUri.getPath(); //from File Manager

			if (path != null) 
				bitmap 	= BitmapFactory.decodeFile(path);
		} else {
			path	= mImageCaptureUri.getPath();
			bitmap  = BitmapFactory.decodeFile(path);
		}

		mImageView.setImageBitmap(bitmap);		
	}

	public String getRealPathFromURI(Uri contentUri) {
        String [] proj 		= {MediaStore.Images.Media.DATA};
        Cursor cursor 		= managedQuery( contentUri, proj, null, null,null);

        if (cursor == null) return null;

        int column_index 	= cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

        cursor.moveToFirst();

        return cursor.getString(column_index);
	}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:padding="10dp">

	<TextView  
    	android:layout_width="fill_parent" 
    	android:layout_height="wrap_content" 
    	android:text="Android Image Choose Example"/>

	<Button 
		android:id="@+id/btn_choose"
		android:text="Choose Image" 		 
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content"
		android:layout_marginTop="10dp"/>

	<ImageView 
		android:id="@+id/iv_pic"
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"		
		android:layout_marginTop="10dp"/>

</LinearLayout>