無法將圖像保存到存儲-Android

Question

package ar.camera;

import android.content.Intent;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;


import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;

import static android.provider.MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE;

public class MainActivity extends AppCompatActivity {

    static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 1;
    private Uri fileUri;

    //create the file URI
    private static Uri getOutputMediaFileUri(int type) {
        return Uri.fromFile(getOutputMediaFile(type));
    }


    private static File getOutputMediaFile(int type){

        final File mediaStorageDir;

        if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
            mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "EMFDetectingApp");
        } else{
            mediaStorageDir = new File ("/storage/sdcard0/EMFDetectingApp");
        }

        if(  !mediaStorageDir.exists()){
            if (! mediaStorageDir.mkdirs()){
                Log.d("EMFDectectingApp", "failed to create directory");
                return null;
            }
        }

        //create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile = null;
        if(type == MEDIA_TYPE_IMAGE) {
            mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
            return mediaFile;
        } else{
            return null;
        }



    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);

        //create the uri of a file to save the image
        fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

        //specifying the path and file name for teh received image
        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data){
        if(requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE){
            if(resultCode == RESULT_OK){
                //image cpatured and saved to fileUri specifies in the Intent
                Toast.makeText(this, "Image successfully saved", Toast.LENGTH_SHORT).show();
            }
            else if(resultCode == RESULT_CANCELED){
                Toast.makeText(this, "Image capture cancelled", Toast.LENGTH_SHORT).show();

            }
            else{
                Toast.makeText(this, "Image capture failed", Toast.LENGTH_SHORT).show();

            }
        }
    }


}

我創建了一個應用程序，該應用程序使用相機拍攝圖像並保存。 但是，當我運行上面的代碼時，我可以拍照，但圖像不會保存。 我在圖庫或SD卡中找不到它。 有人可以在此代碼中找到錯誤嗎？

Answer 1

有人可以在此代碼中找到錯誤嗎？

• 在完成設置Intent之前，您正在調用startActivityForResult() - 在調用startActivityForResult() 之前調用putExtra() startActivityForResult()

• 切勿對路徑進行硬編碼 （例如/storage/sdcard0/EMFDetectingApp ），因為此類路徑可能並不在所有設備上都存在。

• 如果該文件是可移動存儲設備，則/storage/sdcard0/在Android 4.4+設備上寫入/storage/sdcard0/ 。

• 如果targetSdkVersion為24或更高版本，則不能在Android 7.0+設備上使用Uri.fromFile()

• 在Windows / macOS / Linux或大多數畫廊應用程序中，您的照片將是不可見的，除非您使MediaScannerConnection將照片MediaScannerConnection索引 。