从后台线程中解除ProgressDialog时,为什么没有抛出异常？

Question

我知道当我尝试在后台线程上显示ProgressDialog时会抛出异常Can't create handler inside thread that has not called Looper.prepare(),

因为我们正在尝试从后台线程修改UI.但是当我们在后台线程中忽略该对话框时,不会抛出任何异常.为什么我们在后台线程中关闭对话框时没有抛出异常,因为我们也是后台线程中的modifyng UI.

谢谢

Answer 1

这是Dialog的dismiss()方法的代码,显示了为什么没有抛出异常并且dismiss有效:

/**
 * Dismiss this dialog, removing it from the screen. This method can be
 * invoked safely from any thread.  Note that you should not override this
 * method to do cleanup when the dialog is dismissed, instead implement
 * that in {@link #onStop}.
 */
public void dismiss() {
    if (Thread.currentThread() != mUiThread) {
        mHandler.post(mDismissAction);
    } else {
        mDismissAction.run();
    }
}