android - ACTION_IMAGE_CAPTURE - 在默认位置拍照后获取 URI

Question

我正在拍摄如下照片:

activity.startActivityForResult(new Intent(MediaStore.ACTION_IMAGE_CAPTURE), BaseDef.REQUEST_CODE_CAMERA);

之后，我只想获取新图像路径、uri 或类似的(不是位图或图像数据)，以便我知道新图像的位置。因此，我尝试像下面这样检索 uri:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if (requestCode == BaseDef.REQUEST_CODE_CAMERA)
    {
        if (resultCode == RESULT_OK)
        {
            Uri uri = data.getData();
        }
    }
}

但是 uri 有时是 null。如何在此类设备上获取图像路径/uri？

编辑

我真的很想保留使用任何相机应用创建的默认文件名!

当前的解决方法(我不知道这是否总是有效):

    @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if (requestCode == BaseDef.REQUEST_CODE_CAMERA)
    {
        if (resultCode == RESULT_OK)
        {
            String path = null;
            Uri uri = data.getData();
            if (uri != null)
                path = MediaUtil.getRealPathFromURI(uri);
            else
            {
                L.d(this, "URI == NULL => trying to get last image path directly");
                // here I just sort mediastore by id desc and get the first image's path
                // can I be sure this ALWAYS works? 
                // When the camera returns, the image SHOULD be already in the media store
                // If not, I would get a wrong image...
                path = MediaStoreUtil.getLastImagePath(); 
            }

            if (path == null)
            {
                L.d(this, "Path of camera image could not be retrieved");
                return;
            }
        }
    }
}

Answer 1

注意:针对 api-24 或更高版本，see here .

针对 api-23 或更低版本:

执行此操作的最佳方法是发送带有用于打开相机的 Intent 的 Uri。您将需要创建一个临时文件，该文件将被拍摄的照片覆盖。

首先声明一个成员变量来存放Uri:

public class MyPhotoActivity extends AppCompatActivity {

    Uri uri;
    //.............

设置临时文件并将 Uri 传递给相机应用:

public void takePhoto() {
  counter++; //this is an int
  String imageFileName = "JPEG_" + counter; //make a better file name
  File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
  File image = File.createTempFile(imageFileName, 
                                   ".jpg", 
                                   storageDir
                                  );

  uri = Uri.fromFile(image);
  Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
  takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
  startActivityForResult(takePhotoIntent, BaseDef.REQUEST_CODE_CAMERA);
}

然后，如果您在 onActivityResult() 中获得成功结果，创建的临时文件将包含捕获的图像，您可以使用 uri 来满足您的任何需要:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    if (requestCode == BaseDef.REQUEST_CODE_CAMERA)
    {
        if (resultCode == RESULT_OK)
        {
            //use uri member variable...
            //it has the image that was captured
        }
    }
}