Question

我的应用程序对下载文件夹具有读写权限。如何调用默认应用程序打开文件并授予其读取文件的权限？使用此代码时，默认应用程序将打开，但无法访问该文件：

public void openFile(String fileName)
{
    String mimeType = URLConnection.guessContentTypeFromName(fileName);
    Intent newIntent = new Intent(Intent.ACTION_VIEW);
    Uri myUri = Uri.parse(fileName);
    newIntent.setDataAndType(myUri, mimeType);
    newIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);          
    newIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    newIntent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
    try {
        this.startActivity(newIntent);
    } catch (ActivityNotFoundException e) {
        Toast.makeText(this, "No handler for this type of file.", Toast.LENGTH_LONG).show();
    }
}

例如，

Acrobat Reader报告无法访问该文件。仅GoogleFoto应用在打开时会征得其许可并成功打开图片。

Answer 1

感谢CommonsWare

android / AndroidManifest.xml

<!-- file provider for open attached files-->
<provider android:name="android.support.v4.content.FileProvider" android:authorities="XXX.XXXXXXXXXXXX" android:exported="false" android:grantUriPermissions="true">
    <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_provider_paths"/>
</provider>

android / res / xml / file_provider_paths.xml

<paths xmlns:android="http://schemas.android.com/apk/res/android">
  <cache-path name="cache" path="/" />
  <files-path name="files" path="/" />
</paths>

MainActivity.java

public String openFile(String filePath)
{
    File file = new File(filePath);
    if (!file.exists())
        return "file not exist";

    Uri uri = FileProvider.getUriForFile(this, BuildConfig.APPLICATION_ID, file);
    String mimeType = URLConnection.guessContentTypeFromName(filePath);

    Intent newIntent = new Intent(Intent.ACTION_VIEW);
    newIntent.setDataAndType(uri, mimeType);
    newIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);                  
    newIntent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    newIntent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);

    try {
        this.startActivity(newIntent);
    } catch (ActivityNotFoundException e) {
        Toast.makeText(this, "No handler for this type of file.", Toast.LENGTH_LONG).show();
        return "No handler for this type of file.";
    }
    return "";
}

使用默认应用程序打开文件（具有权限强制执行）

1 个答案: