VB.NET RaiseEvent要求表达式

Question

我正在学习VB.NET中的键盘钩子，需要帮助解决错误。起初它告诉我必须改变（Not（KeyDown）Is Nothing）＆amp; KeyUp to RaiseEvent因为它们是事件，我已经完成了。但现在它告诉我一个＆＃39;）＆＃39;表达是预期的，我不知道这意味着什么。我使用VB.NET wiki和代码片段做到了这一点，我为自己感到骄傲。我现在不希望这个翻牌。请帮忙！最底层有一个错误的图像。

protected static void setAnimatedImagesForImageView(final Context context, ImageView imageView, Uri[] imageUris, int showImageDurationMillis, int fadeImageDurationMillis) {

    AnimationDrawable animation = new AnimationDrawable();
    animation.setEnterFadeDuration(fadeImageDurationMillis);
    animation.setExitFadeDuration(fadeImageDurationMillis);

    boolean imageAdded = false;
    for (int i = 0; i < imageUris.length; i++) {
        if (imageUris[i] != null) {
            Drawable drawable = getDrawable(context, imageUris[i]);
            animation.addFrame(drawable, showImageDurationMillis);
            imageAdded = true;
        }
    }

    if (imageAdded) {
        animation.setOneShot(false);
        imageView.setImageDrawable(animation);
        animation.start();
    }

}

Answer 1

你应该只是举起事件..如果有什么东西在听它，它就会运行。如果没有，则不会造成伤害。

Public Event KeyDown As KeyboardHookCallback
Public Event KeyUp As KeyboardHookCallback

Private Function HookFunc(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
    If (nCode >= 0) Then
        Dim iwParam As Integer = wParam.ToInt32
        If ((iwParam = WM_KEYDOWN) OrElse (iwParam = WM_SYSKEYDOWN)) Then
            RaiseEvent KeyDown(CType(Marshal.ReadInt32(lParam), VKeys))
        End If

        If ((iwParam = WM_KEYUP) OrElse (iwParam = WM_SYSKEYUP)) Then
            RaiseEvent KeyUp(CType(Marshal.ReadInt32(lParam), VKeys))
        End If

    End If
    Return CallNextHookEx(hookID, nCode, wParam, lParam)
End Function