优化部分代码

rong_im/kit/src/main/java/io/rong/imkit/activity/FilePreviewActivity.java

@@ -145,7 +145,9 @@ public class FilePreviewActivity extends RongBaseActivity implements View.OnClic
         mFileMessage = getIntent().getParcelableExtra("FileMessage");
         mMessage = getIntent().getParcelableExtra("Message");
         mProgress = getIntent().getIntExtra("Progress", 0);
-
+        if (mFileMessage == null) {
+            return;
+        }
         mToasts = new ArrayList<>();
         mFileName = mFileMessage.getName();
         mFileTypeImage.setImageResource(FileTypeUtils.fileTypeImageId(this, mFileName));