onFileUriExposed

App在StrictMode(严格)模式下运行模式下报的异常

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 Holder$1.onClick(MailAnnexAdapter.java:75)
                  at android.view.View.performClick(View.java:5204)
                  at android.view.View$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)

定位异常方法

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);
    }

具体异常位置

Uri.fromFile(file)

Android官网对这个异常的解释

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。因此，尝试传递 file:// URI 会触发 FileUriExposedException。分享私有文件内容的推荐方法是使用 FileProvider。

意思就是从7.0起不能使用绝对Uri地址，使用FileProvider转换URL
那就来看怎么使用FileProvider使用
原来方法改为

@Override
    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 | Intent.FLAG_GRANT_READ_URI_PERMISSION);
        Uri contentUri = FileProvider.getUriForFile(activity, OFRConstants.Authorities.AUTHORITIES_FILEPROVIDER, file);
        String contentMIMEType = activity.getContentResolver().getType(contentUri);
        intent.setDataAndType(contentUri, contentMIMEType);
        try {
            ActivityCompat.startActivity(activity, intent, null);
        } catch (ActivityNotFoundException e) {
            ToastUtils.showToast(activity, R.string.not_found_open_tool);
        }
    }

public static class Authorities {
        public static final String AUTHORITIES_FILEPROVIDER = "com.mysiga.offer.fileprovider";
    }

在AndroidManifest.xml定义

<provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.mysiga.offer.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/paths_file" />
        </provider>

xml下的paths_file.xml文件

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path
        name="annex"
        path="mysiga/annex/" />
</paths>

就解决报错了。