glide有IllegalStateException("Failed to generate expected directory: " + expectedDirectory)报错是怎么回事

报错的原因

glide的 IllegalStateException 异常是由于在手机上没有写入权限或者没有足够的存储空间导致的。在加载图片时，Glide会尝试在手机上创建一个临时目录来存储图片，如果没有写入权限或者没有足够的存储空间，就会抛出这个异常。

你可以尝试以下几种方法来解决这个问题

1.在AndroidManifest.xml中添加写入权限

2.在你的activity 或者 fragment中动态获取权限

if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)
        != PackageManager.PERMISSION_GRANTED) {
    // Permission is not granted
    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
        // Show an explanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.
    } else {
        // No explanation needed; request the permission
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
    }
} else {
    // Permission has already been granted
}

3.检查你的手机存储空间是否足够

4. 使用Glide的缓存目录来配置缓存位置。

Glide.get(context).setDiskCache(
        new ExternalPreferredCacheDiskCacheFactory(context, diskCacheFolderName, diskCacheSize));

5.在你的Application中配置缓存大小和目录

public class MyApp extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        Glide.get(this).setMemoryCategory(MemoryCategory.HIGH);
        Glide.get(this).setDiskCache(new InternalCacheDiskCacheFactory(this, cacheSize100MegaBytes));
    }
}

6. 清除缓存

// Clear memory cache
Glide.get(context).clearMemory();
// Clear disk cache
Glide.get(context).clearDiskCache();

这些都是一些可能导致"Failed to generate expected directory"错误的原因和解决方案。最终的解决方案可能因您的应用程序和环境而异。如果问题仍然存在，请提供更多的细节和代码，我会尽力帮助您。

如何解决

首先，您需要确定出现错误的原因。如果是因为没有写入权限或者没有足够的存储空间，则可以尝试以下解决方案：

1.在AndroidManifest.xml中添加写入权限

2.在你的activity 或者 fragment中动态获取权限

if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)
        != PackageManager.PERMISSION_GRANTED) {
    // Permission is not granted
    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
        // Show an explanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.
    } else {
        // No explanation needed; request the permission
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
    }
} else {
    // Permission has already been granted
}

3.检查你的手机存储空间是否足够

如果是因为其他原因，你可以尝试以上其他解决方案，如使用缓存目录来配置缓存位置，在你的Application中配置缓存大小和目录，清除缓存。

如果问题仍然存在，请提供更多的细节和代码，我会尽力帮助您。

使用例子

当然有，以下是一个在应用程序中动态获取写入权限的示例：

public class MainActivity extends AppCompatActivity {
    private static final int MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {

            // Permission is not granted
            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                // Show an explanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.
            } else {
                // No explanation needed; request the permission
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                        MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);

                // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
                // app-defined int constant. The callback method gets the
                // result of the request.
            }
        } else {
            // Permission has already been granted
        }
    }
    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    // permission was granted, yay! Do the
                    // contacts-related task you need to do.
                } else {
                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.
                }
                return;
            }

            // other 'case' lines to check for other
            // permissions this app might request.
        }
    }

}

在这个例子中，我们首先检查是否已经获得了写入权限。如果没有，我们就解释为什么需要这项权限，并请求用户授予权限。当用户授予权限后，我们可以在 onRequestPermissionsResult() 方法中检查结果。如果权限被授予，我们就可以继续执行需要写入权限的操作，如果权限被拒绝，我们就需要禁用依赖于该权限的功能。

这只是一个简单的示例，您可以根据需要自由扩展和修改。