Question

如何正确使用QNetworkReply？我见过这样的例子：

void HttpDownload::on_downloadButton_clicked()
{
    // get url
    url = (ui->urlEdit->text());

    // get() method posts a request
    // to obtain the contents of the target request
    // and returns a new QNetworkReply object
    // opened for reading which emits
    // the readyRead() signal whenever new data arrives.
    reply = manager->get(QNetworkRequest(url));

    // Whenever more data is received from the network,
    // this readyRead() signal is emitted
    connect(reply, SIGNAL(finished()),
            this, SLOT(handleFinish()));
}

在构建连接之前是否可能发出完成的信号？

Answer 1

检查错误

.draw { 
  position: relative; 
  width: 400px;
  height: 400px;
  border: 1px #ccc dashed;
}

.draw div { position: absolute; }

.draw div[class^="h"] {
  height: 20%;
  width: 100%;
  left: 0;
  background: #d8d8d8;
}

.draw div[class^="v"] {
  height: 100%;
  width: 20%;
  top: 0;
  background: #212121;
}

.draw .h1 { top : 20%; }
.draw .h2 { top : 60%; }
.draw .v1 { left : 20%; }
.draw .v2 { left : 60%; }

.draw .v1:before { 
  position: inherit;
  z-index: 2;
  top: 20%;
  left: 0;
  width: 100%;
  height: 20%;
  content: "";
  background: inherit;
}

我认为在错误情况下也会发出完成的信号，并且在建立连接之前它可能看起来像已完成。

Answer 2

当然可以。一旦连接不再继续，就会发出finished信号，并且不再发出任何信号。信号的意思是，基本上＆＃34;我完成了发射信号，我的状态现在已经设定了＃34;。任何不可恢复的错误条件必然会以finished信号的发射结束。

问：正确使用QNetworkReply？

2 个答案: