Android通过手机拍照或从本地相册选取图片设置头像

像微信、QQ、微博等社交类的APP，通常都有设置头像的功能，设置头像通常有两种方式： 

让用户通过选择本地相册之类的图片库中已有的图像，裁剪后作为头像。 

让用户启动手机的相机拍照，拍完照片后裁剪，然后作为头像。 

我现在写一个简单的完整代码例子，说明如何在Android中实现上述两个头像设置功能。 

MainActivity.Java文件： 

package zhangpgil.photo;import java.io.File;import android.support.v7.app.ActionBarActivity;import android.view.View;import android.widget.Button;import android.widget.ImageView;import android.widget.Toast;import android.content.Intent;import android.graphics.Bitmap;import android.net.Uri;import android.os.Bundle;import android.os.Environment;import android.provider.MediaStore;public class MainActivity extends ActionBarActivity {  private static final String IMAGE_FILE_NAME = "temp_head_image.jpg";  private static final int CODE_GALLERY_REQUEST = 0xa0; private static final int CODE_CAMERA_REQUEST = 0xa1; private static final int CODE_RESULT_REQUEST = 0xa2; // 裁剪后图片的宽(X)和高(Y),480 X 480的正方形。 private static int output_X = 480; private static int output_Y = 480; private ImageView headImage = null; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); headImage = (ImageView) findViewById(R.id.imageView); Button buttonLocal = (Button) findViewById(R.id.buttonLocal); buttonLocal.setOnClickListener(new View.OnClickListener() {  @Override  public void onClick(View v) {  choseHeadImageFromGallery();  } }); Button buttonCamera = (Button) findViewById(R.id.buttonCamera); buttonCamera.setOnClickListener(new View.OnClickListener() {  @Override  public void onClick(View v) {  choseHeadImageFromCameraCapture();  } }); } // 从本地相册选取图片作为头像 private void choseHeadImageFromGallery() { Intent intentFromGallery = new Intent(); // 设置文件类型 intentFromGallery.setType("image public void cropRawPhoto(Uri uri) { Intent intent = new Intent("com.android.camera.action.CROP"); intent.setDataAndType(uri, "image private void setImageToHeadView(Intent intent) { Bundle extras = intent.getExtras(); if (extras != null) {  Bitmap photo = extras.getParcelable("data");  headImage.setImageBitmap(photo); } }  public static boolean hasSdcard() { String state = Environment.getExternalStorageState(); if (state.equals(Environment.MEDIA_MOUNTED)) {  // 有存储的SDCard  return true; } else {  return false; } }}