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();
                }
            }
        }
    }
}

以下是hcpl发布的优良代码的更新。但这适用于OI文件管理器，astro文件管理器和媒体库(测试)。所以我想它将适用于每个文件管理器(除了上面提到的这些，还有很多其他的吗?)修改了他写的代码。

public class BrowsePicture extends Activity {

    //YOU CAN EDIT THIS TO WHATEVER YOU WANT
    private static final int SELECT_PICTURE = 1;

    private String selectedImagePath;
    //ADDED
    private String filemanagerstring;

    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);
            }
        });
    }

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

                //OI FILE Manager
                filemanagerstring = selectedImageUri.getPath();

                //MEDIA GALLERY
                selectedImagePath = getPath(selectedImageUri);

                //DEBUG PURPOSE - you can delete this if you want
                if(selectedImagePath!=null)
                    System.out.println(selectedImagePath);
                else System.out.println("selectedImagePath is null");
                if(filemanagerstring!=null)
                    System.out.println(filemanagerstring);
                else System.out.println("filemanagerstring is null");

                //NOW WE HAVE OUR WANTED STRING
                if(selectedImagePath!=null)
                    System.out.println("selectedImagePath is the right one for you!");
                else
                    System.out.println("filemanagerstring is the right one for you!");
            }
        }
    }

    //UPDATED!
    public String getPath(Uri uri) {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        if(cursor!=null)
        {
            //HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL
            //THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA
            int column_index = cursor
            .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }
        else return null;
    }

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。

在上面代码的基础上，我反映了如下代码，可能它更适合:

public String getPath(Uri uri) {
    String selectedImagePath;
    //1:MEDIA GALLERY --- query from MediaStore.Images.Media.DATA
    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();
        selectedImagePath = cursor.getString(column_index);
    }else{
        selectedImagePath = null;
    }

    if(selectedImagePath == null){
        //2:OI FILE Manager --- call method: uri.getPath()
        selectedImagePath = uri.getPath();
    }
    return selectedImagePath;
}

最快的方式打开图像从画廊或相机。

原始参考:从画廊在android程序中获取图像

下面的方法将从图库或相机接收图像，并将其显示在ImageView中。所选图像将存储在内部。

XML代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.exampledemo.parsaniahardik.uploadgalleryimage.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/btn"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="20dp"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="Capture Image and upload to server" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Below image is fetched from server"
        android:layout_marginTop="5dp"
        android:textSize="23sp"
        android:gravity="center"
        android:textColor="#000"/>

    <ImageView
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:layout_gravity="center"
        android:layout_marginTop="10dp"
        android:scaleType="fitXY"
        android:src="@mipmap/ic_launcher"
        android:id="@+id/iv"/>

</LinearLayout>

JAVA类

import android.content.Intent;
import android.graphics.Bitmap;
import android.media.MediaScannerConnection;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import com.androidquery.AQuery;
import org.json.JSONException;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Calendar;
import java.util.HashMap;

public class MainActivity extends AppCompatActivity implements AsyncTaskCompleteListener{

    private ParseContent parseContent;
    private Button btn;
    private ImageView imageview;
    private static final String IMAGE_DIRECTORY = "/demonuts_upload_camera";
    private final int CAMERA = 1;
    private AQuery aQuery;

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

        parseContent = new ParseContent(this);
        aQuery = new AQuery(this);

        btn = (Button) findViewById(R.id.btn);
        imageview = (ImageView) findViewById(R.id.iv);

        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
                startActivityForResult(intent, CAMERA);
            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == this.RESULT_CANCELED) {
            return;
        }
        if (requestCode == CAMERA) {
            Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
            String path = saveImage(thumbnail);
            try {
                uploadImageToServer(path);
            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }

    private void uploadImageToServer(final String path) throws IOException, JSONException {

        if (!AndyUtils.isNetworkAvailable(MainActivity.this)) {
            Toast.makeText(MainActivity.this, "Internet is required!", Toast.LENGTH_SHORT).show();
            return;
        }

        HashMap<String, String> map = new HashMap<String, String>();
        map.put("url", "https://demonuts.com/Demonuts/JsonTest/Tennis/uploadfile.php");
        map.put("filename", path);
        new MultiPartRequester(this, map, CAMERA, this);
        AndyUtils.showSimpleProgressDialog(this);
    }

    @Override
    public void onTaskCompleted(String response, int serviceCode) {
        AndyUtils.removeSimpleProgressDialog();
        Log.d("res", response.toString());
        switch (serviceCode) {

            case CAMERA:
                if (parseContent.isSuccess(response)) {
                    String url = parseContent.getURL(response);
                    aQuery.id(imageview).image(url);
                }
        }
    }

    public String saveImage(Bitmap myBitmap) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        myBitmap.compress(Bitmap.CompressFormat.JPEG, 90, bytes);
        File wallpaperDirectory = new File(
                Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY);
        // have the object build the directory structure, if needed.
        if (!wallpaperDirectory.exists()) {
            wallpaperDirectory.mkdirs();
        }

        try {
            File f = new File(wallpaperDirectory, Calendar.getInstance()
                    .getTimeInMillis() + ".jpg");
            f.createNewFile();
            FileOutputStream fo = new FileOutputStream(f);
            fo.write(bytes.toByteArray());
            MediaScannerConnection.scanFile(this,
                    new String[]{f.getPath()},
                    new String[]{"image/jpeg"}, null);
            fo.close();
            Log.d("TAG", "File Saved::--->" + f.getAbsolutePath());

            return f.getAbsolutePath();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
        return "";
    }
}

万一有用的话;我这样做是为了得到位图:

InputStream is = context.getContentResolver().openInputStream(imageUri);
Bitmap bitmap = BitmapFactory.decodeStream(is);