需要浏览按钮吗？

Question

您好，我正在开发一个需要使用浏览按钮选择文件的应用程序。 如何在android中实现浏览按钮？

Answer 1

以下是我的示例应用程序的完整代码。我使用了一个按钮，可以从您手机的任何目录中选择文件。

---

布局

file_picker_empty_view.xml

<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:text="No files or directories"
android:background="@android:drawable/toast_frame"
android:textSize="28sp"
android:gravity="center_vertical|center_horizontal"/>

file_picker_list_item.xml

<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:orientation="horizontal" >
  <ImageView
      android:id="@+id/file_picker_image"
      android:layout_width="40dip"
      android:layout_height="40dip"
      android:layout_marginTop="5dip"
      android:layout_marginBottom="5dip"
      android:layout_marginLeft="5dip"
      android:src="@drawable/file"
      android:scaleType="centerCrop"/>
  <TextView
      android:id="@+id/file_picker_text"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content"
      android:layout_weight="1"
      android:layout_gravity="left|center_vertical"
      android:textSize="28sp"
      android:layout_marginLeft="10dip"
      android:singleLine="true"
      android:text="filename"/>
</LinearLayout>

file_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_height="wrap_content" 
android:orientation="vertical"
android:layout_width="fill_parent">
    <TextView android:text="@+id/TextView01" 
    android:id="@+id/TextView01" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:singleLine="true" 
    android:textStyle="bold" 
    android:layout_marginTop="5dip" 
    android:layout_marginLeft="5dip"></TextView>
    <TextView android:text="@+id/TextView02" 
    android:id="@+id/TextView02" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginLeft="10dip"></TextView>
</LinearLayout>

main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center_vertical">
    <Button android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/start_file_picker_button"
        android:text="Browse" />
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Selected file"
        android:textStyle="bold"
        android:textColor="#fff"
        android:textSize="24sp" />
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/file_path_text_view"
        android:text="No file has been selected"
        android:textSize="18sp" />
</LinearLayout>

活动是

FilePickerActivity

import java.io.File;
import java.io.FilenameFilter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import android.app.ListActivity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;

/**
 * 
 * @author pankaj
 *
 */
public class FilePickerActivity extends ListActivity {

    public final static String EXTRA_FILE_PATH = "file_path";
    public final static String EXTRA_SHOW_HIDDEN_FILES = "show_hidden_files";
    public final static String EXTRA_ACCEPTED_FILE_EXTENSIONS = "accepted_file_extensions";
    private final static String DEFAULT_INITIAL_DIRECTORY = "/";

    protected File mDirectory;
    protected ArrayList<File> mFiles;
    protected FilePickerListAdapter mAdapter;
    protected boolean mShowHiddenFiles = false;
    protected String[] acceptedFileExtensions;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Set the view to be shown if the list is empty
        LayoutInflater inflator = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View emptyView = inflator.inflate(R.layout.file_picker_empty_view, null);
        ((ViewGroup)getListView().getParent()).addView(emptyView);
        getListView().setEmptyView(emptyView);

        // Set initial directory
        mDirectory = new File(DEFAULT_INITIAL_DIRECTORY);

        // Initialize the ArrayList
        mFiles = new ArrayList<File>();

        // Set the ListAdapter
        mAdapter = new FilePickerListAdapter(this, mFiles);
        setListAdapter(mAdapter);

        // Initialize the extensions array to allow any file extensions
        acceptedFileExtensions = new String[] {};

        // Get intent extras
        if(getIntent().hasExtra(EXTRA_FILE_PATH)) {
            mDirectory = new File(getIntent().getStringExtra(EXTRA_FILE_PATH));
        }
        if(getIntent().hasExtra(EXTRA_SHOW_HIDDEN_FILES)) {
            mShowHiddenFiles = getIntent().getBooleanExtra(EXTRA_SHOW_HIDDEN_FILES, false);
        }
        if(getIntent().hasExtra(EXTRA_ACCEPTED_FILE_EXTENSIONS)) {
            ArrayList<String> collection = getIntent().getStringArrayListExtra(EXTRA_ACCEPTED_FILE_EXTENSIONS);
            acceptedFileExtensions = (String[]) collection.toArray(new String[collection.size()]);
        }
    }

    @Override
    protected void onResume() {
        refreshFilesList();
        super.onResume();
    }

    /**
     * Updates the list view to the current directory
     */
    protected void refreshFilesList() {
        // Clear the files ArrayList
        mFiles.clear();

        // Set the extension file filter
        ExtensionFilenameFilter filter = new ExtensionFilenameFilter(acceptedFileExtensions);

        // Get the files in the directory
        File[] files = mDirectory.listFiles(filter);
        if(files != null && files.length > 0) {
            for(File f : files) {
                if(f.isHidden() && !mShowHiddenFiles) {
                    // Don't add the file
                    continue;
                }

                // Add the file the ArrayAdapter
                mFiles.add(f);
            }

            Collections.sort(mFiles, new FileComparator());
        }
        mAdapter.notifyDataSetChanged();
    }

    @Override
    public void onBackPressed() {
        if(mDirectory.getParentFile() != null) {
            // Go to parent directory
            mDirectory = mDirectory.getParentFile();
            refreshFilesList();
            return;
        }

        super.onBackPressed();
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        File newFile = (File)l.getItemAtPosition(position);

        if(newFile.isFile()) {
            // Set result
            Intent extra = new Intent();
            extra.putExtra(EXTRA_FILE_PATH, newFile.getAbsolutePath());
            setResult(RESULT_OK, extra);
            // Finish the activity
            finish();
        } else {
            mDirectory = newFile;
            // Update the files list
            refreshFilesList();
        }

        super.onListItemClick(l, v, position, id);
    }

    private class FilePickerListAdapter extends ArrayAdapter<File> {

        private List<File> mObjects;

        public FilePickerListAdapter(Context context, List<File> objects) {
            super(context, R.layout.file_picker_list_item, android.R.id.text1, objects);
            mObjects = objects;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            View row = null;

            if(convertView == null) { 
                LayoutInflater inflater = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                row = inflater.inflate(R.layout.file_picker_list_item, parent, false);
            } else {
                row = convertView;
            }

            File object = mObjects.get(position);

            ImageView imageView = (ImageView)row.findViewById(R.id.file_picker_image);
            TextView textView = (TextView)row.findViewById(R.id.file_picker_text);
            // Set single line
            textView.setSingleLine(true);

            textView.setText(object.getName());
            if(object.isFile()) {
                // Show the file icon
                imageView.setImageResource(R.drawable.file);
            } else {
                // Show the folder icon
                imageView.setImageResource(R.drawable.folder);
            }

            return row;
        }

    }

    private class FileComparator implements Comparator<File> {
        public int compare(File f1, File f2) {
            if(f1 == f2) {
                return 0;
            }
            if(f1.isDirectory() && f2.isFile()) {
                // Show directories above files
                return -1;
            }
            if(f1.isFile() && f2.isDirectory()) {
                // Show files below directories
                return 1;
            }
            // Sort the directories alphabetically
            return f1.getName().compareToIgnoreCase(f2.getName());
        }
    }

    private class ExtensionFilenameFilter implements FilenameFilter {
        private String[] mExtensions;

        public ExtensionFilenameFilter(String[] extensions) {
            super();
            mExtensions = extensions;
        }

        public boolean accept(File dir, String filename) {
            if(new File(dir, filename).isDirectory()) {
                // Accept all directory names
                return true;
            }
            if(mExtensions != null && mExtensions.length > 0) {
                for(int i = 0; i < mExtensions.length; i++) {
                    if(filename.endsWith(mExtensions[i])) {
                        // The filename ends with the extension
                        return true;
                    }
                }
                // The filename did not match any of the extensions
                return false;
            }
            // No extensions has been set. Accept all file extensions.
            return true;
        }
    }
}

MainActivity // 这必须是您的默认 Activity，作为清单中的 MAIN

public class MainActivity extends Activity implements OnClickListener {

    private static final int REQUEST_PICK_FILE = 1;

    private TextView mFilePathTextView;
    private Button mStartActivityButton;
    private File selectedFile;

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

        // Set the views
        mFilePathTextView = (TextView)findViewById(R.id.file_path_text_view);
        mStartActivityButton = (Button)findViewById(R.id.start_file_picker_button);
        mStartActivityButton.setOnClickListener(this);      
    }

    public void onClick(View v) {
        switch(v.getId()) {
        case R.id.start_file_picker_button:
            // Create a new Intent for the file picker activity
            Intent intent = new Intent(this, FilePickerActivity.class);

            // Set the initial directory to be the sdcard
            //intent.putExtra(FilePickerActivity.EXTRA_FILE_PATH, Environment.getExternalStorageDirectory());

            // Show hidden files
            //intent.putExtra(FilePickerActivity.EXTRA_SHOW_HIDDEN_FILES, true);

            // Only make .png files visible
            //ArrayList<String> extensions = new ArrayList<String>();
            //extensions.add(".png");
            //intent.putExtra(FilePickerActivity.EXTRA_ACCEPTED_FILE_EXTENSIONS, extensions);

            // Start the activity
            startActivityForResult(intent, REQUEST_PICK_FILE);
            break;

        case R.id.You_can_handle_more_onclick_events_from_here:
            //Do something
            break;
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(resultCode == RESULT_OK) {
            switch(requestCode) {
            case REQUEST_PICK_FILE:
                if(data.hasExtra(FilePickerActivity.EXTRA_FILE_PATH)) {
                    // Get the file path
                    selectedFile = new File(data.getStringExtra(FilePickerActivity.EXTRA_FILE_PATH));
                    // Set the file path text view
                    mFilePathTextView.setText(selectedFile.getPath());  
                    //Now you have your selected file, You can do your additional requirement with file.                
                }
            }
        }
    }
}

我正在上传图片，您可以使用自己的图片。

图片名称：文件

图像名称：文件夹

最后

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="org.myContactAdder.adder"
      android:versionCode="1"
      android:versionName="1.0">
      <uses-permission android:name="android.permission.READ_CONTACTS" />
      <uses-permission android:name="android.permission.WRITE_CONTACTS" />
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".FilePickerActivity"
                  android:label="@string/app_name">
        </activity>
        <activity android:name=".MainActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-sdk android:minSdkVersion="7" />

</manifest> 

这些是更多信息的链接：Android file picker Activity 和 Creating simple file chooser。

Answer 2

你需要做的：

1. 创建一个运行单独活动的按钮（startActivityForResult）。

2. 此文件选择活动应列出来自特定位置的所有文件和文件夹。如果您单击一个文件夹，则会为该文件夹重新初始化活动（列出其中的文件）。

3. 如果点击了一个文件，那么活动应该设置结果，将文件名传递给 extras，然后完成。

Answer 3

这里有一些代码可以用来做一个文件选择器：

http://www.kaloer.com/android-file-picker-activity

它有一个 Apache 许可证。