java - FileProvider.getUriForFile 返回空对象引用

Question

FileProvider.getUriForFile 返回一个空对象引用，我不知道为什么。这以前有效。以下错误是我得到的。我还在错误下方添加了我的代码。

Process: com.example.joche.mywarranty, PID: 2522
                                                                        java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference
                                                                            at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:584)
                                                                            at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:558)
                                                                            at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:400)
                                                                            at com.example.joche.mywarranty.InputScreen$2.onClick(InputScreen.java:74)
                                                                            at android.view.View.performClick(View.java:5610)
                                                                            at android.view.View$PerformClick.run(View.java:22265)
                                                                            at android.os.Handler.handleCallback(Handler.java:751)
                                                                            at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                            at android.os.Looper.loop(Looper.java:154)
                                                                            at android.app.ActivityThread.main(ActivityThread.java:6077)
                                                                            at java.lang.reflect.Method.invoke(Native Method)
                                                                            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
                                                                            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)

代码:

imageUri = FileProvider.getUriForFile(context, context.getApplicationContext().getPackageName() + ".my.package.inputName.provider", new File(fileinputName));

AndroidManifest.xml 文件:

<provider
        android:name=".GenericFileProvider"
        android:authorities="${applicationId}.my.package.name.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths"/>
    </provider>

当然还有带有路径的 xml 文件:

<?xml version="1.0" encoding="utf-8"?><paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="my_images" path="."/></paths>

Answer 1

在 list 中将其声明为 android:authorities="${applicationId}.my.package.name.provider"

并且您尝试将其用作不同的名称:context.getApplicationContext().getPackageName() + ".my.package.inputName.provider"

两者必须匹配。选择一个并在两个地方使用:.my.package.name.provider 或 .my.package.inputName.provider