Android更换头像功能实现

现在不管什么APP都有个头像，如果你看见没有头像的APP就会感觉非常奇怪，以前头像都是方的，后来就变成圆的，我估计在过个几年就得来个五角星形状的头像，下面我把更换头像的代码写来：

<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"    tools:context=".MainActivity" >    <ImageView        android:id="@+id/iv_head"        android:layout_width="200dip"        android:layout_height="200dip"        android:layout_alignParentTop="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="210dip"        android:src="@drawable/ic_launcher" />    <Button        android:id="@+id/btn_takephoto"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentLeft="true"        android:layout_alignParentTop="true"        android:text="拍照" />    <Button        android:id="@+id/btn_photos"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignParentRight="true"        android:layout_alignParentTop="true"        android:text="从相册取" /></RelativeLayout>

首先我定义了一个非常简单的XML布局，里面两个Button，一个ImageView用来显示头像：

下面我来看看MainActivity代码：

package com.example.changhead;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.provider.MediaStore;import android.annotation.SuppressLint;import android.app.Activity;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ImageView;@SuppressLint("SdCardPath")public class MainActivity extends Activity implements OnClickListener {private ImageView ivHead;//头像显示private Button btnTakephoto;//拍照private Button btnPhotos;//相册private Bitmap head;//头像Bitmapprivate static String path="/sdcard/myHead/";//sd路径@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initView();}private void initView() {//初始化控件btnPhotos = (Button) findViewById(R.id.btn_photos);btnTakephoto = (Button) findViewById(R.id.btn_takephoto);btnPhotos.setOnClickListener(this);btnTakephoto.setOnClickListener(this);ivHead = (ImageView) findViewById(R.id.iv_head);Bitmap bt = BitmapFactory.decodeFile(path + "head.jpg");//从Sd中找头像，转换成Bitmapif(bt!=null){@SuppressWarnings("deprecation")Drawable drawable = new BitmapDrawable(bt);//转换成drawableivHead.setImageDrawable(drawable);}else{/** *如果SD里面没有则需要从服务器取头像，取回来的头像再保存在SD中 *  */}}@Overridepublic void onClick(View v) {switch (v.getId()) {case R.id.btn_photos://从相册里面取照片Intent intent1 = new Intent(Intent.ACTION_PICK, null);intent1.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");startActivityForResult(intent1, 1);break;case R.id.btn_takephoto://调用相机拍照Intent intent2 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);intent2.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(Environment.getExternalStorageDirectory(),"head.jpg")));startActivityForResult(intent2, 2);//采用ForResult打开break;default:break;}}protected void onActivityResult(int requestCode, int resultCode, Intent data) {switch (requestCode) {case 1:if (resultCode == RESULT_OK) {cropPhoto(data.getData());//裁剪图片}break;case 2:if (resultCode == RESULT_OK) {File temp = new File(Environment.getExternalStorageDirectory()+ "/head.jpg");cropPhoto(Uri.fromFile(temp));//裁剪图片}break;case 3:if (data != null) {Bundle extras = data.getExtras();head = extras.getParcelable("data");if(head!=null){/** * 上传服务器代码 */setPicToView(head);//保存在SD卡中ivHead.setImageBitmap(head);//用ImageView显示出来}}break;default:break;}super.onActivityResult(requestCode, resultCode, data);};/** * 调用系统的裁剪 * @param uri */public void cropPhoto(Uri uri) {Intent intent = new Intent("com.android.camera.action.CROP");intent.setDataAndType(uri, "image/*");intent.putExtra("crop", "true"); // aspectX aspectY 是宽高的比例intent.putExtra("aspectX", 1);intent.putExtra("aspectY", 1);// outputX outputY 是裁剪图片宽高intent.putExtra("outputX", 150);intent.putExtra("outputY", 150);intent.putExtra("return-data", true);startActivityForResult(intent, 3);}private void setPicToView(Bitmap mBitmap) { String sdStatus = Environment.getExternalStorageState();          if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用                 return;             }  FileOutputStream b = null;File file = new File(path);file.mkdirs();// 创建文件夹String fileName =path + "head.jpg";//图片名字try {b = new FileOutputStream(fileName);mBitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把数据写入文件} catch (FileNotFoundException e) {e.printStackTrace();} finally {try {//关闭流b.flush();b.close();} catch (IOException e) {e.printStackTrace();}}}}

上面的注释已经很详细了，就这些

对了不要忘记加权限：

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