PhotoTask持有解码的数据和显示数据的View对象的引用，它从PhotoDecodeRunnable接收到状态码，并且沿着线程池里引用的对象和Handler实例传送。
复制代码
public class PhotoTask {
...
// Gets a handle to the object that creates the thread pools
sPhotoManager = PhotoManager.getInstance();
...
public void handleDecodeState(int state) {
int outState;
// Converts the decode state to the overall state.
switch(state) {
case PhotoDecodeRunnable.DECODE_STATE_COMPLETED:
outState = PhotoManager.TASK_COMPLETE;
break;
...
}
...
// Calls the generalized state method
handleState(outState);
}
...
// Passes the state to PhotoManager
void handleState(int state) {
/*
* Passes a handle to this task and the
* current state to the class that created
* the thread pools
*/
sPhotoManager.handleState(this, state);
}
...
}
移动数据到UI
PhotoManager从PhotoTask对象接收到状态码和PhotoTask对象的句柄。因为状态是TASK_COMPLETE，创建一个包含状态和任务对象的Message，发送给Handler。
复制代码
public class PhotoManager {
...
// Handle status messages from tasks
public void handleState(PhotoTask photoTask, int state) {
switch (state) {
...
