如何使用 MaterialFilePicker？

Question

我正在尝试为我的 Android Java 音乐播放器使用 MaterialFilePicker。我已将它包含在我的两个

build.gradle

文件中，并相应地调整了我的

colors.xml

和

styles.xml

文件，但不知道下一步该去哪里。 GitHub 存储库中的

readme.md

文件告诉我：

打开你的课程并添加以下代码

并为我提供了这段代码：

...
public static final int FILE_PICKER_REQUEST_CODE = 989
...

MaterialFilePicker()
    // Pass a source of context. Can be:
    //    .withActivity(Activity activity)
    //    .withFragment(Fragment fragment)
    //    .withSupportFragment(androidx.fragment.app.Fragment fragment)
    .withActivity(this)
    // With cross icon on the right side of toolbar for closing picker straight away
    .withCloseMenu(true)
    // Entry point path (user will start from it)
    .withPath(alarmsFolder.absolutePath)
    // Root path (user won't be able to come higher than it)
    .withRootPath(externalStorage.absolutePath)
    // Showing hidden files
    .withHiddenFiles(true)
    // Want to choose only jpg images
    .withFilter(Pattern.compile(".*\\.(jpg|jpeg)$"))
    // Don't apply filter to directories names
    .withFilterDirectories(false)
    .withTitle("Sample title")
    .withRequestCode(FILE_PICKER_REQUEST_CODE)
    .start()
...

但是我不知道如何实现这段代码。 我创建了一个名为

MaterialFilePicker.java

的文件，并将提供的代码修改为如下所示：

package com.infinityfreeapp.formalsoftware.audioplayer;

import java.util.regex.Pattern;
import MaterialFilePicker;

public class MaterialFilePicker {
    public static final int FILE_PICKER_REQUEST_CODE = 989;


    MaterialFilePicker() {
        // Pass a source of context. Can be:
        //    .withActivity(Activity activity)
        //    .withFragment(Fragment fragment)
        //    .withSupportFragment(androidx.fragment.app.Fragment fragment)
        .withActivity(this)
        // With cross icon on the right side of toolbar for closing picker straight away
        .withCloseMenu(true)
        // Entry point path (user will start from it)
        .withPath(alarmsFolder.absolutePath)
        // Root path (user won't be able to come higher than it)
        .withRootPath(externalStorage.absolutePath)
        // Showing hidden files
        .withHiddenFiles(true)
        // Want to choose only jpg images
        .withFilter(Pattern.compile(".*\\.(jpg|jpeg)$"))
        // Don't apply filter to directories names
        .withFilterDirectories(false)
        .withTitle("Sample title")
        .withRequestCode(FILE_PICKER_REQUEST_CODE)
        .start();
    }
}

但是还是错误百出