• 先看异常信息:

E/StrictMode: null
              java.lang.Throwable: file:// Uri exposed through Intent.getData()
                  at android.os.StrictMode.onFileUriExposed(StrictMode.java:1757)
                  at android.net.Uri.checkFileUriExposed(Uri.java:2346)
                  at android.content.Intent.prepareToLeaveProcess(Intent.java:8045)
                  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1506)
                  at android.app.Activity.startActivityForResult(Activity.java:3930)
                  at android.app.Activity.startActivityForResult(Activity.java:3890)
                  at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:843)
                  at android.app.Activity.startActivity(Activity.java:4213)
                  at android.support.v4.app.ActivityCompatJB.startActivity(ActivityCompatJB.java:26)
                  at android.support.v4.app.ActivityCompat.startActivity(ActivityCompat.java:133)
                  at com.horizon.offer.mail.maildetail.impl.ImageAnnexWrapper.openFile(ImageAnnexWrapper.java:26)
                  at com.horizon.offer.mail.maildetail.MailDetailActivity.openAnnexFile(MailDetailActivity.java:184)
                  at com.horizon.offer.mail.maildetail.adapter.MailAnnexAdapter$MailAnnexViewHolder$1.onClick(MailAnnexAdapter.java:75)
                  at android.view.View.performClick(View.java:5204)
                  at android.view.View$PerformClick.run(View.java:21153)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:148)
                  at android.app.ActivityThread.main(ActivityThread.java:5417)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

在StrictMode(严格)模式下，App之间共享资源报的异常。

• 出现这个异常的代码

public void openFile(@NonNull Activity activity, @NonNull File file) {
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.addCategory(Intent.CATEGORY_DEFAULT);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        /**异常这行代码**/
        intent.setDataAndType(Uri.fromFile(file), "image/*");
        ActivityCompat.startActivity(activity, intent, null);
    }

打印

Uri.fromFile(file)

输出信息

Uri uri=file:///storage/emulated/0/download/9text.jpg

• 各方说明

  • Android N中说明Uri不能以file://的原因
    • 传递软件包网域外的 file:// URI 可能给接收器留下无法访问的路径。
    • 访问权限控制

• 解决办法

  • FileProvider

• 总结

  • 开始搜索Uri.fromFile(file)并分析源码

    ````
    /**

  • Creates a Uri from a file. The URI has the form
  • “file://“. Encodes path characters with the exception of
  • ‘/‘.

  • Example: "file:///tmp/android.txt"

  • @throws NullPointerException if file is null
  • @return a Uri for the given file

  */
  public static Uri fromFile(File file) {
  if (file == null) {
  throw new NullPointerException(“file”);
  }

    PathPart path = PathPart.fromDecoded(file.getAbsolutePath());
    return new HierarchicalUri(
            "file", Part.EMPTY, path, Part.NULL, Part.NULL);
  

  }
  ````
  没有找到相关解决方案。

  • StrictMode的FileUriExposedException异常检测中有提到FileProvider的使用
  • 我写的一个demo
  • 给以后提醒app之间共享数据传Uri不能传file://

• 参考资料

  • StrictMode
  • Android Uri和Java URI的区别
  • Android的Uri
  • Uri详解之——Uri结构与代码提取
  • 根据 Android Training课程写的FileProvider小例子
  • FileUriExposedException 异常
  • FileProvider
  • FileProvider使用