假设在SD卡目录中有一个图像文件夹仅用于图像。

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// tells your intent to get the contents
// opens the URI for your image directory on your sdcard
intent.setType("file:///sdcard/image/*"); 
startActivityForResult(intent, 1);

然后，您可以决定如何处理活动中的内容。

这是一个检索图像路径名称的示例，用您的代码进行测试，以确保您可以处理返回的结果。您可以根据需要更改代码以更好地满足您的需求。

protected final void onActivityResult(final int requestCode, final int
                     resultCode, final Intent i) {
    super.onActivityResult(requestCode, resultCode, i);

  // this matches the request code in the above call
  if (requestCode == 1) {
      Uri _uri = i.getData();

    // this will be null if no image was selected...
    if (_uri != null) {
      // now we get the path to the image file
     cursor = getContentResolver().query(_uri, null,
                                      null, null, null);
     cursor.moveToFirst();
     String imageFilePath = cursor.getString(0);
     cursor.close();
     }
   }

我的建议是尽量让检索图像工作正确，我认为问题是在存储卡上访问图像的内容。看一下在sd卡上显示图像。

如果您能够启动并运行它(可能通过示例提供正确的提供程序)，那么您应该能够为您的代码找到一种变通方法。

通过更新这个问题来让我了解你的进展。祝你好运

public class BrowsePictureActivity extends Activity {

    // this is the action code we use in our intent, 
    // this way we know we're looking at the response from our own action
    private static final int SELECT_PICTURE = 1;

    private String selectedImagePath;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ((Button) findViewById(R.id.Button01))
                .setOnClickListener(new OnClickListener() {

                    public void onClick(View arg0) {

                        // in onCreate or any event where your want the user to
                        // select a file
                        Intent intent = new Intent();
                        intent.setType("image/*");
                        intent.setAction(Intent.ACTION_GET_CONTENT);
                        startActivityForResult(Intent.createChooser(intent,
                                "Select Picture"), SELECT_PICTURE);
                    }
                });
    }

    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == RESULT_OK) {
            if (requestCode == SELECT_PICTURE) {
                Uri selectedImageUri = data.getData();
                selectedImagePath = getPath(selectedImageUri);
            }
        }
    }

    /**
     * helper to retrieve the path of an image URI
     */
    public String getPath(Uri uri) {
            // just some safety built in 
            if( uri == null ) {
                // TODO perform some logging or show user feedback
                return null;
            }
            // try to retrieve the image from the media store first
            // this will only work for images selected from gallery
            String[] projection = { MediaStore.Images.Media.DATA };
            Cursor cursor = managedQuery(uri, projection, null, null, null);
            if( cursor != null ){
                int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                cursor.moveToFirst();
                return cursor.getString(column_index);
            }
            // this is our fallback here
            return uri.getPath();
    }

}

假设在SD卡目录中有一个图像文件夹仅用于图像。

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// tells your intent to get the contents
// opens the URI for your image directory on your sdcard
intent.setType("file:///sdcard/image/*"); 
startActivityForResult(intent, 1);

然后，您可以决定如何处理活动中的内容。

这是一个检索图像路径名称的示例，用您的代码进行测试，以确保您可以处理返回的结果。您可以根据需要更改代码以更好地满足您的需求。

protected final void onActivityResult(final int requestCode, final int
                     resultCode, final Intent i) {
    super.onActivityResult(requestCode, resultCode, i);

  // this matches the request code in the above call
  if (requestCode == 1) {
      Uri _uri = i.getData();

    // this will be null if no image was selected...
    if (_uri != null) {
      // now we get the path to the image file
     cursor = getContentResolver().query(_uri, null,
                                      null, null, null);
     cursor.moveToFirst();
     String imageFilePath = cursor.getString(0);
     cursor.close();
     }
   }

我的建议是尽量让检索图像工作正确，我认为问题是在存储卡上访问图像的内容。看一下在sd卡上显示图像。

如果您能够启动并运行它(可能通过示例提供正确的提供程序)，那么您应该能够为您的代码找到一种变通方法。

通过更新这个问题来让我了解你的进展。祝你好运

这是我的例子，可能不完全是你的情况。

假设你从你的API提供者获得base64格式，给它一个文件名和文件扩展名，将它保存到文件系统中的某个位置。

public static void shownInBuiltInGallery(final Context ctx, String strBase64Image, final String strFileName, final String strFileExtension){

new AsyncTask<String, String, File>() {
    @Override
    protected File doInBackground(String... strBase64Image) {

        Bitmap bmpImage = convertBase64StringToBitmap(strBase64Image[0], Base64.NO_WRAP);

        if(bmpImage == null) {
            cancel(true);
            return null;
        }

        byte[] byImage = null;

        if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_JPG) == 0) {
            byImage = convertToJpgByte(bmpImage); // convert bitmap to binary for latter use
        } else if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_PNG) == 0){
            byImage = convertToPngByte(bmpImage); // convert bitmap to binary for latter use
        } else if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_BMP) == 0){
            byImage = convertToBmpByte(bmpImage); // convert bitmap to binary for latter use
        } else {
            cancel(true);
            return null;
        }

        if(byImage == null) {
            cancel(true);
            return null;
        }

        File imageFolder = ctx.getExternalCacheDir();

        if(imageFolder.exists() == false){
            if(imageFolder.mkdirs() == false){
                cancel(true);
                return null;
            }
        }

        File imageFile = null;

        try {
            imageFile = File.createTempFile(strFileName, strFileExtension, imageFolder);
        } catch (IOException e){
            e.printStackTrace();
        }

        if(imageFile == null){
            cancel(true);
            return null;
        }

        if (imageFile.exists() == true) {
            if(imageFile.delete() == false){
                cancel(true);
                return null;
            }
        }

        FileOutputStream fos = null;

        try {
            fos = new FileOutputStream(imageFile.getPath());
            fos.write(byImage);
            fos.flush();
            fos.close();
        } catch (java.io.IOException e) {
            e.printStackTrace();
        } finally {
            fos = null;
        }

        return imageFile;
    }

    @Override
    protected void onPostExecute(File file) {
        super.onPostExecute(file);

            String strAuthority = ctx.getPackageName() + ".provider";
            Uri uriImage = FileProvider.getUriForFile(ctx, strAuthority, file);

            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(uriImage, "image/*");
            intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            ctx.startActivity(intent);

    }
}.execute(strBase64Image);}

不要忘记在AndroidManifest.xml中首先设置一个适当的文件提供程序

        <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">

        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths"/>
    </provider>

文件路径是XML在…/res/ XML /file_path.xml

<?xml version="1.0" encoding="utf-8"?>

<external-files-path name="external_files" path="Accessory"/>

<external-path name="ex_Download" path="Download/" />
<external-path name="ex_Pictures" path="Pictures/" />

<external-files-path name="my_Download" path="Download/" />
<external-files-path name="my_Pictures" path="Pictures/" />
<external-cache-path name="my_cache" path="." />

<files-path name="private_Download" path="Download/" />
<files-path name="private_Pictures" path="Pictures/" />
<cache-path name="private_cache" path="." />

长话短说，首先准备好文件提供程序，将已知且可访问的图片源的Uri传递给Intent，否则，将图片保存在所需的位置，然后将位置(作为Uri)传递给Intent。

hcpl的方法在kitkat之前工作得很好，但不能与DocumentsProvider API一起工作。为此，只需简单地遵循官方的Android文档提供者教程:https://developer.android.com/guide/topics/providers/document-provider.html ->打开一个文档，位图部分。

简单地，我使用了hcpl的代码并扩展了它:如果图像的检索路径的文件抛出异常，我调用这个函数:

private Bitmap getBitmapFromUri(Uri uri) throws IOException {
        ParcelFileDescriptor parcelFileDescriptor =
             getContentResolver().openFileDescriptor(uri, "r");
        FileDescriptor fileDescriptor = parcelFileDescriptor.getFileDescriptor();
        Bitmap image = BitmapFactory.decodeFileDescriptor(fileDescriptor);
        parcelFileDescriptor.close();
        return image;
}

在Nexus 5上测试。

请找到从图库中选择单个图像的答案

import android.app.Activity;
import android.net.Uri;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

public class PickImage extends Activity {

    Button btnOpen, btnGet, btnPick;
    TextView textInfo1, textInfo2;
    ImageView imageView;

    private static final int RQS_OPEN_IMAGE = 1;
    private static final int RQS_GET_IMAGE = 2;
    private static final int RQS_PICK_IMAGE = 3;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.image_pick);
        btnOpen = (Button)findViewById(R.id.open);
        btnGet = (Button)findViewById(R.id.get);
        btnPick = (Button)findViewById(R.id.pick);
        textInfo1 = (TextView)findViewById(R.id.info1);
        textInfo2 = (TextView)findViewById(R.id.info2);
        imageView = (ImageView) findViewById(R.id.image);

        btnOpen.setOnClickListener(btnOpenOnClickListener);
        btnGet.setOnClickListener(btnGetOnClickListener);
        btnPick.setOnClickListener(btnPickOnClickListener);
    }

    View.OnClickListener btnOpenOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent();
            intent.setAction(Intent.ACTION_OPEN_DOCUMENT);
            intent.addCategory(Intent.CATEGORY_OPENABLE);
            intent.setType("image/*");

            startActivityForResult(intent, RQS_OPEN_IMAGE);
        }
    };

    View.OnClickListener btnGetOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent();
            intent.setAction(Intent.ACTION_GET_CONTENT);
            intent.addCategory(Intent.CATEGORY_OPENABLE);
            intent.setType("image/*");

            startActivityForResult(intent, RQS_OPEN_IMAGE);
        }
    };

    View.OnClickListener btnPickOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(Intent.ACTION_PICK,
                    android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(intent, RQS_PICK_IMAGE);
        }
    };

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == Activity.RESULT_OK) {


            if (requestCode == RQS_OPEN_IMAGE ||
                    requestCode == RQS_GET_IMAGE ||
                    requestCode == RQS_PICK_IMAGE) {

                imageView.setImageBitmap(null);
                textInfo1.setText("");
                textInfo2.setText("");

                Uri mediaUri = data.getData();
                textInfo1.setText(mediaUri.toString());
                String mediaPath = mediaUri.getPath();
                textInfo2.setText(mediaPath);

                //display the image
                try {
                    InputStream inputStream = getBaseContext().getContentResolver().openInputStream(mediaUri);
                    Bitmap bm = BitmapFactory.decodeStream(inputStream);

                   ByteArrayOutputStream stream = new ByteArrayOutputStream();
                    byte[] byteArray = stream.toByteArray();

                    imageView.setImageBitmap(bm);

                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}