In service-oriented architecture, accurately predicting the Quality of Service (QoS) is vital for maintaining reliability and enhancing user satisfaction. However, current methods often neglect high-order latent collaborative relationships and fail to dynamically adjust feature learning for specific user-service invocations, which are critical for precise feature extraction. Moreover, relying on RNNs to capture QoS evolution limits the ability to detect long-term trends due to challenges in managing long-range dependencies. To address these issues, we propose the Target-Prompt Online Graph Collaborative Learning (TOGCL) framework for temporal QoS prediction. It leverages a dynamic user-service invocation graph to comprehensively model historical interactions. Building on this graph, it develops a target-prompt graph attention network to extract online deep latent features of users and services at each time slice, considering implicit target-neighboring collaborative relationships and historical QoS values. Additionally, a multi-layer Transformer encoder is employed to uncover temporal feature evolution patterns, enhancing temporal QoS prediction. Extensive experiments on the WS-DREAM dataset demonstrate that TOGCL significantly outperforms state-of-the-art methods across multiple metrics, achieving improvements of up to 38.80\%. These results underscore the effectiveness of TOGCL for temporal QoS prediction.