Android 微信文件分享大小限制

微信开放文档没有关于分享文件的介绍，在网上收到了解决方案如下：

fun shareFileToWechat(filePath: String, title: String, type: String = "file"): Boolean {
    val api = WXAPIFactory.createWXAPI(
      getContext(),
      wxKey,
      true
    )
    if (api.isWXAppInstalled) {
      api.registerApp(wxKey)
      val fileObj = WXFileObject()
      fileObj.fileData = WXUtil.inputStreamToByte(filePath)
      fileObj.filePath = filePath
      //使用媒体消息分享
      val  msg = WXMediaMessage()
      msg.mediaObject = fileObj
      msg.title = title
      //发送请求
      val req = Req()
      //创建唯一标识
      req.transaction = buildTransaction(trim(type))
      req.message = msg
      req.scene = Req.WXSceneSession
      api.sendReq(req)
      return true
    } else {
      ToastUtil.toast(string.uninstall_wechat)
      return false
    }
  }

这种方案是将文件的路径和文件的字节数组都传递给微信，文件大小超过1MB，文件分享页面跳转失败。

public void serialize(Bundle var1) {
  var1.putByteArray("_wxfileobject_fileData", this.fileData);
  var1.putString("_wxfileobject_filePath", this.filePath);
}

文件的路径和文件的字节数组是通过Bundle传递的，Bundle最大支持传递1MB的数据，所以跳转失败，解决方案是删除fileObj.fileData = WXUtil.inputStreamToByte(filePath)这行代码，最终代码如下：

fun shareFileToWechat(filePath: String, title: String, type: String = "file"): Boolean {
    val api = WXAPIFactory.createWXAPI(
      getContext(),
      wxKey,
      true
    )
    if (api.isWXAppInstalled) {
      api.registerApp(wxKey)
      val fileObj = WXFileObject()
      fileObj.filePath = filePath
      //使用媒体消息分享
      val  msg = WXMediaMessage()
      msg.mediaObject = fileObj
      msg.title = title
      //发送请求
      val req = Req()
      //创建唯一标识
      req.transaction = buildTransaction(trim(type))
      req.message = msg
      req.scene = Req.WXSceneSession
      api.sendReq(req)
      return true
    } else {
      ToastUtil.toast(string.uninstall_wechat)
      return false
    }
  }

但第二种方案也无法分享10MB以上的文件，因为微信平台做了限制，会对文件的大小进行合法检验。

private int contentLengthLimit = 10485760;

public boolean checkArgs() {
  if (this.fileData != null && this.fileData.length != 0 || this.filePath != null && this.filePath.length() != 0) {
    if (this.fileData != null && this.fileData.length > this.contentLengthLimit) {
      Log.e("MicroMsg.SDK.WXFileObject", "checkArgs fail, fileData is too large");
      return false;
    } else if (this.filePath != null && this.getFileSize(this.filePath) > this.contentLengthLimit) {
      Log.e("MicroMsg.SDK.WXFileObject", "checkArgs fail, fileSize is too large");
      return false;
    } else {
      return true;
    }
  } else {
    Log.e("MicroMsg.SDK.WXFileObject", "checkArgs fail, both arguments is null");
    return false;
  }
}