在 android 中选择特定类型的文件

Selecting a specific type of file in android

我正在尝试制作一个应用程序,用户可以使用 android 设备的文件管理器 select 一个文件。这是我正在使用的代码:

 boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
                    if (isKitKat)
                    {
                        Intent uploadIntent = new Intent();
                        uploadIntent.setType("*/*");
                        uploadIntent.setAction(Intent.ACTION_GET_CONTENT);
                        startActivityForResult(uploadIntent, REPORT_USING_FILE_MANAGER);

                    }
                    else
                    {
                        Intent uploadIntent = new Intent(Intent.ACTION_GET_CONTENT);
                        uploadIntent.setType("*/*");
                        startActivityForResult(uploadIntent, REPORT_USING_FILE_MANAGER);
                    }

我只希望用户能够 select 图像文件(.jpg、.png 等)或 .pdf 文件。如何设置此限制?

您正在使用 loadIntent.setType("*/*"); 选择所有类型的文件。

您必须使用 MIME 类型对其进行过滤。

例如,如果您想选择 jpeg 文件,那么

loadIntent.setType("image/jpeg");

部分MIME类型如下,

image/jpeg
audio/mpeg4-generic
text/html
audio/mpeg
audio/aac
audio/wav
audio/ogg
audio/midi
audio/x-ms-wma
video/mp4
video/x-msvideo
video/x-ms-wmv
image/png
image/jpeg
image/gif
.xml ->text/xml
.txt -> text/plain
.cfg -> text/plain
.csv -> text/plain
.conf -> text/plain
.rc -> text/plain
.htm -> text/html
.html -> text/html
.pdf -> application/pdf
.apk -> application/vnd.android.package-archive

如果您有任何问题,请告诉我。

您需要为图像文件

实施 "photoPickerIntent"
Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, SELECT_PHOTO);

之后应完成以下操作:

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent)
    {
        switch (requestCode)
        {
            case SELECT_PHOTO:
                if (resultCode == RESULT_OK)
                {
                    Uri selectedImage = intent.getData();
                    System.out.println(selectedImage.toString() + "-" + selectedImage.getPath());

                    String[] filePathColumn = {MediaStore.Images.Media.DATA};
                    // Get the cursor
                    Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
                    // Move to first row
                    cursor.moveToFirst();

                    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);

                    imgDecodableString = cursor.getString(columnIndex);
                    cursor.close();

                }
                break;
            default:
                break;
        }

    }