Question

我尝试保存位图，但第outStream = new FileOutputStream(file);行始终抛出错误java.io.FileNotFoundException: /storage/emulated/0/inpaint/card.png: open failed: ENOENT (No such file or directory)。

    //Save bitmap
    InputStream inputStream = null;
    try {
        inputStream = getContentResolver().openInputStream(uri);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

    Bitmap bmp = BitmapFactory.decodeStream(inputStream);
    File f3=new File(Environment.getExternalStorageDirectory()+"/inpaint/");
    if(!f3.exists())
        f3.mkdirs();
    OutputStream outStream = null;
    File file = new File(Environment.getExternalStorageDirectory() + "/inpaint/"+"card"+".png");
    try {
        outStream = new FileOutputStream(file);
        bmp.compress(Bitmap.CompressFormat.PNG, 90, outStream);
        outStream.close();
        Toast.makeText(getApplicationContext(), "Saved", Toast.LENGTH_LONG).show();
    } catch (Exception e) {
        e.printStackTrace();
    }

我还添加了

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

到清单。

Answer 1

如果您的设备包含棉花糖，请提供许可运行时间：

;with ServerPermsAndRoles as
(
    select
        spr.name as principal_name,
        spr.type_desc as principal_type,
        spm.permission_name collate SQL_Latin1_General_CP1_CI_AS as security_entity,
        'permission' as security_type,
        spm.state_desc
    from sys.server_principals spr
    inner join sys.server_permissions spm
    on spr.principal_id = spm.grantee_principal_id
    where spr.type in ('s', 'u')

    union all

    select
        sp.name as principal_name,
        sp.type_desc as principal_type,
        spr.name as security_entity,
        'role membership' as security_type,
        null as state_desc
    from sys.server_principals sp
    inner join sys.server_role_members srm
    on sp.principal_id = srm.member_principal_id
    inner join sys.server_principals spr
    on srm.role_principal_id = spr.principal_id
    where sp.type in ('s', 'u')
)
select *
from ServerPermsAndRoles
order by principal_name

通过以下方法传递位图：

       private static final int PERMISSION_REQUEST_CODE = 1;
      if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {

        if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)
                == PackageManager.PERMISSION_DENIED) {

            Log.d("permission", "permission denied to WRITE_EXTERNAL_STORAGE - requesting it");
            String[] permissions = {Manifest.permission.WRITE_EXTERNAL_STORAGE};

            requestPermissions(permissions, PERMISSION_REQUEST_CODE);

        }
    }

Answer 2

您可以应用以下代码 -

final int MyVersion = Build.VERSION.SDK_INT;
if (MyVersion > Build.VERSION_CODES.LOLLIPOP_MR1) {
                                if (!checkIfAlreadyhavePermission()) {
                                   ActivityCompat.requestPermissions(YourActivity.this, new String[]{android.Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
                                } else {
                                    your_method();
                                }
                                } else {
                                    your_method();
                            }

private void your_code(){
      //Your entire code will go here
}

public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case 1: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    your_method();
                } else {
                    Toast.makeText(getApplicationContext(), "Please provide access to external storage", Toast.LENGTH_LONG).show();
                }
                break;
            }
   }
}

Answer 3

我认为你和我有同样的问题。在Android版本23或更高版本中，您需要向用户询问代码中的额外存储权限。详情请见以下链接。

http://www.androidhowtocode.com/2017/01/javaiofilenotfoundexception.html

Answer 4

您可以使用此单行将图像保存在图片文件夹中，并将位图传递到以下行：

MediaStore.Images.Media.insertImage（getApplicationContext（）。getContentResolver（），bitmap，“Detected Image”，“”）;

无法保存位图：ENOENT（没有此类文件或目录）

4 个答案: