Android开发中怎么实现一个图片上传功能

private void showDialog() {  View view = getLayoutInflater().inflate(R.layout.user_header_dialog, null);  final Dialog dialog = new Dialog(this, R.style.transparentFrameWindowStyle);  dialog.setContentView(view, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));  Window window = dialog.getWindow();  // 设置显示动画  window.setWindowAnimations(R.style.main_menu_animstyle);  WindowManager.LayoutParams wl = window.getAttributes();  wl.x = 0;  wl.y = getWindowManager().getDefaultDisplay().getHeight();  // 以下这两句是为了保证按钮可以水平满屏  wl.width = ViewGroup.LayoutParams.MATCH_PARENT;  wl.height = ViewGroup.LayoutParams.WRAP_CONTENT;  // 设置显示位置  dialog.onWindowAttributesChanged(wl);  // 设置点击外围解散  dialog.setCanceledOnTouchOutside(true);  dialog.show();  btn_picture = (Button) window.findViewById(R.id.btn_picture);  btn_photo = (Button) window.findViewById(R.id.btn_photo);  btn_cancle = (Button) window.findViewById(R.id.btn_cancle);  btn_picture.setOnClickListener(new View.OnClickListener() {// 图库     @SuppressLint("InlinedApi")     @Override     public void onClick(View v) {      Intent intent = new Intent(PhotoSelectActivity.this, AlbumActivity.class);      startActivity(intent);      dialog.dismiss();     }    });  btn_photo.setOnClickListener(new View.OnClickListener() {// 相机     @SuppressLint("InlinedApi")     @Override     public void onClick(View v) {      photo();      dialog.dismiss();     }    });  btn_cancle.setOnClickListener(new View.OnClickListener() {// 取消     @Override     public void onClick(View v) {      dialog.dismiss();     }    }); }