Android个人中心的头像上传，图片编码及截取实例

public class MainActivity extends AppCompatActivity implements View.OnClickListener {  private ImageView iv_img;  private Button bt_camera;  private Button bt_xiangce;  private static final int PHOTO_REQUEST_CAREMA = 1;// 拍照  private static final int PHOTO_REQUEST_GALLERY = 2;// 从相册中选择  private static final int PHOTO_REQUEST_CUT = 3;// 结果  /* 头像名称 */  private static final String PHOTO_FILE_NAME = "temp_photo.jpg";  private File tempFile;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    //加载控件    initView();  }  private void initView() {    iv_img = (ImageView) findViewById(R.id.iv_img);    bt_camera = (Button) findViewById(R.id.bt_camera);    bt_xiangce = (Button) findViewById(R.id.bt_xiangce);    //从SharedPreferences获取图片    getBitmapFromSharedPreferences();    //监听两个按钮，相册按钮和相机按钮    bt_camera.setOnClickListener(this);    bt_xiangce.setOnClickListener(this);  }  @Override  public void onClick(View v) {    switch (v.getId()) {      case R.id.bt_camera:        // 激活相机        Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");        // 判断存储卡是否可以用，可用进行存储        if (hasSdcard()) {          tempFile = new File(Environment.getExternalStorageDirectory(), PHOTO_FILE_NAME);          // 从文件中创建uri          Uri uri = Uri.fromFile(tempFile);          intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);        }        // 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_CAREMA        startActivityForResult(intent, PHOTO_REQUEST_CAREMA);        break;      case R.id.bt_xiangce:        // 激活系统图库，选择一张图片        Intent intent1 = new Intent(Intent.ACTION_PICK);        intent1.setType("image/*");        // 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_GALLERY        startActivityForResult(intent1, PHOTO_REQUEST_GALLERY);        break;    }  }  /*   * 判断sdcard是否被挂载   */  private boolean hasSdcard() {    //判断ＳＤ卡手否是安装好的　　　media_mounted    if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {      return true;    } else {      return false;    }  }  /*   * 剪切图片   */  private void crop(Uri uri) {    // 裁剪图片意图    Intent intent = new Intent("com.android.camera.action.CROP");    intent.setDataAndType(uri, "image/*");    intent.putExtra("crop", "true");    // 裁剪框的比例，1：1    intent.putExtra("aspectX", 1);    intent.putExtra("aspectY", 1);    // 裁剪后输出图片的尺寸大小    intent.putExtra("outputX", 250);    intent.putExtra("outputY", 250);    intent.putExtra("outputFormat", "JPEG");// 图片格式    intent.putExtra("noFaceDetection", true);// 取消人脸识别    intent.putExtra("return-data", true);    // 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_CUT    startActivityForResult(intent, PHOTO_REQUEST_CUT);  }  /**   *   * @param requestCode   * @param resultCode   * @param data   */  @Override  protected void onActivityResult(int requestCode, int resultCode, Intent data) {    if (requestCode == PHOTO_REQUEST_GALLERY) {      // 从相册返回的数据      if (data != null) {        // 得到图片的全路径        Uri uri = data.getData();        crop(uri);      }    } else if (requestCode == PHOTO_REQUEST_CAREMA) {      // 从相机返回的数据      if (hasSdcard()) {        crop(Uri.fromFile(tempFile));      } else {        Toast.makeText(MainActivity.this, "未找到存储卡，无法存储照片！", Toast.LENGTH_SHORT).show();      }    } else if (requestCode == PHOTO_REQUEST_CUT) {      // 从剪切图片返回的数据      if (data != null) {        Bitmap bitmap = data.getParcelableExtra("data");        /**         * 获得图片         */        iv_img.setImageBitmap(bitmap);        //保存到SharedPreferences        saveBitmapToSharedPreferences(bitmap);      }      try {        // 将临时文件删除        tempFile.delete();      } catch (Exception e) {        e.printStackTrace();      }    }    super.onActivityResult(requestCode, resultCode, data);  }  //保存图片到SharedPreferences  private void saveBitmapToSharedPreferences(Bitmap bitmap) {    // Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);    //第一步:将Bitmap压缩至字节数组输出流ByteArrayOutputStream    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();    bitmap.compress(Bitmap.CompressFormat.PNG, 80, byteArrayOutputStream);    //第二步:利用Base64将字节数组输出流中的数据转换成字符串String    byte[] byteArray = byteArrayOutputStream.toByteArray();    String imageString = new String(Base64.encodeToString(byteArray, Base64.DEFAULT));    //第三步:将String保持至SharedPreferences    SharedPreferences sharedPreferences = getSharedPreferences("testSP", Context.MODE_PRIVATE);    SharedPreferences.Editor editor = sharedPreferences.edit();    editor.putString("image", imageString);    editor.commit();    //上传头像    setImgByStr(imageString,"");  }  /**   * 上传头像   * @param imgStr   * @param imgName   */  public void setImgByStr(String imgStr, String imgName) {  //这里是头像接口，通过Post请求，拼接接口地址和ID，上传数据。    String url = "http://这里写的是接口地址（具体接收格式要看后台怎么给）";    Map<String, String> params = new HashMap<String, String>();    params.put("id", "11111111");// 11111111    params.put("data", imgStr);    OkHttp.postAsync(url, params, new OkHttp.DataCallBack() {      @Override      public void requestFailure(Request request, IOException e) {        Log.i("上传失败", "失败" + request.toString() + e.toString());      }      @Override      public void requestSuccess(String result) throws Exception {        Toast.makeText(MainActivity.this,"上传成功",Toast.LENGTH_SHORT).show();        Log.i("上传成功", result);      }    });  }  //从SharedPreferences获取图片  private void getBitmapFromSharedPreferences(){    SharedPreferences sharedPreferences=getSharedPreferences("testSP", Context.MODE_PRIVATE);    //第一步:取出字符串形式的Bitmap    String imageString=sharedPreferences.getString("image", "");    //第二步:利用Base64将字符串转换为ByteArrayInputStream    byte[] byteArray= Base64.decode(imageString, Base64.DEFAULT);    if(byteArray.length==0){      iv_img.setImageResource(R.mipmap.ic_launcher);    }else{      ByteArrayInputStream byteArrayInputStream=new ByteArrayInputStream(byteArray);      //第三步:利用ByteArrayInputStream生成Bitmap      Bitmap bitmap= BitmapFactory.decodeStream(byteArrayInputStream);      iv_img.setImageBitmap(bitmap);    }  }}