Android中ImageView实现选择本地图片并显示功能

<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" > 
 <imageview 
  android:id="@+id/image_choose" 
  android:layout_width="250dp" 
  android:layout_height="250dp" 
  android:background="#cc0000" 
  android:layout_centerhorizontal="true" 
  android:layout_margintop="30dp" 
  android:src="@drawable/default_bg" 
  android:padding="5dp" 
  /> 
</relativelayout> 

package com.example.chooseimage; 
import android.os.bundle; 
import android.provider.mediastore; 
import android.app.activity; 
import android.content.intent; 
import android.view.view; 
import android.view.view.onclicklistener; 
import android.view.window; 
import android.widget.imageview; 
public class mainactivity extends activity implements onclicklistener { 
 private imageview image_choose; 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
  super.oncreate(savedinstancestate); 
  requestwindowfeature(window.feature_no_title); 
  setcontentview(r.layout.activity_main); 
  image_choose = (imageview) findviewbyid(r.id.image_choose); 
  image_choose.setonclicklistener(this); 
 } 
 @override 
 public void onclick(view v) { 
  // todo auto-generated method stub 
  switch (v.getid()) { 
  case r.id.image_choose: { 
   intent intent = new intent(intent.action_pick, null); 
   intent.setdataandtype(mediastore.images.media.external_content_uri, 
     "image/*"); 
   startactivityforresult(intent, 0x1); 
   break; 
  } 
  } 
 } 
 @override 
 protected void onactivityresult(int requestcode, int resultcode, intent data) { 
  // todo auto-generated method stub 
  if (requestcode == 0x1 && resultcode == result_ok) { 
   if (data != null) { 
    image_choose.setimageuri(data.getdata()); 
   } 
  } 
  super.onactivityresult(requestcode, resultcode, data); 
 } 
}