qt isvalid
bool QMetaProperty::isValid() const. Returns true if this property is valid (readable); otherwise returns false . See also isReadable(). ,bool QModelIndex::isValid() const. Returns true if this model index is valid; otherwise returns false . A valid index belongs to a model, and has non-negative row ...
| 相關軟體 Qt (32-bit) 資訊 | |
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 qt isvalid 相關參考資料
QItemSelectionRange Class | Qt Core 5.13.0 - Qt Documentation
bool, isValid() const. int, left() const. const QAbstractItemModel ... bool QItemSelectionRange::isValid() const. Returns true if the selection range is valid; ... https://doc.qt.io QMetaProperty Class | Qt Core 5.13.0 - Qt Documentation
bool QMetaProperty::isValid() const. Returns true if this property is valid (readable); otherwise returns false . See also isReadable(). https://doc.qt.io QModelIndex Class | Qt Core 5.13.0 - Qt Documentation
bool QModelIndex::isValid() const. Returns true if this model index is valid; otherwise returns false . A valid index belongs to a model, and has non-negative row ... https://doc.qt.io QNetworkCacheMetaData Class | Qt Network 5.13.0 - Qt Documentation
QNetworkCacheMetaData::QNetworkCacheMetaData(). Constructs an invalid network cache meta data. See also isValid(). https://doc.qt.io QPersistentModelIndex Class | Qt Core 5.13.0 - Qt Documentation
bool QPersistentModelIndex::isValid() const. Returns true if this persistent model index is valid; otherwise returns false . A valid index belongs to a model, and ... https://doc.qt.io QSignalSpy Class | Qt Test 5.13.0 - Qt Documentation
bool, isValid() const ... valid signal of object), an explanatory warning message will be output using qWarning() and subsequent calls to isValid() will return false. https://doc.qt.io QSizeF Class | Qt Core 5.13.0 - Qt Documentation
The isValid() function determines if a size is valid. A valid size has both width and height greater than or equal to zero. The isEmpty() function returns true if either ... https://doc.qt.io QSqlError Class | Qt SQL 5.13.0 - Qt Documentation
bool QSqlError::isValid() const. Returns true if an error is set, otherwise false. Example: QSqlQueryModel model; model.setQuery("select * from myTable"); if ... https://doc.qt.io QSqlRelation Class | Qt SQL 5.13.0 - Qt Documentation
bool, isValid() const. void, swap(QSqlRelation &other) ... return an empty string. See also isValid(). ... bool QSqlRelation::isValid() const. Returns true if the ... https://doc.qt.io Qt 菜鸟的坑QAbstractSocket::isValid() - 漫不经心- CSDN博客
我曾经多次在Qt socket 编程中使用tcpSocket.isValid 来判断我当前的连接是否可用，最近写程序时才发现此法并不妥当。 https://blog.csdn.net |