Question

我有一个用于排序的菜单项。当用户单击该按钮时，将创建具有排序选项的PopupMenu。

现在我为每个项目创建了RadioButtons，但似乎无法将所选单选按钮设置为检查状态。我不知道出了什么问题。

这是我的menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <group
        android:id="@+id/group"
        android:checkableBehavior="single">
        <item
            android:id="@+id/fileName"
            android:title="Name" />

        <item
            android:id="@+id/fileDate"
            android:title="Date" />

    </group>

</menu>

这就是我在onOptionsItemSelected（）

中所拥有的

if (id == R.id.sort) {

            final PopupMenu popupMenu = new PopupMenu(getActivity(), view);
            popupMenu.getMenuInflater().inflate(R.menu.sort_menu, popupMenu.getMenu());

            popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {

                public boolean onMenuItemClick(MenuItem item) {

                    int id = item.getItemId();

                    if (id == R.id.fileName) {
                        sortOrder = 0;

                    } else if (id == R.id.fileDate) {
                        sortOrder = 1;

                    } else if (id == R.id.fileSizeInc) {
                        sortOrder = 2;

                    } else if (id == R.id.fileSizeDec) {
                        sortOrder = 3;

                    }

                    item.setChecked(!item.isChecked());

                    return true;
                }
            });

            popupMenu.show();

        }

任何人都可以帮我解决吗？

更新

我意识到@gfpacheco回答的错误。我需要在显示弹出菜单之后而不是之前执行此操作。但问题是如何才能获得特定的ClickItem，以便我可以在回调之外以编程方式检查它？

Answer 1

首先，您应该有一个字段来保存当前的排序顺序，可能是默认值。

其次，在调用popupMenu.show()之前，您应该设置相应的单选按钮选中状态：

MenuItem menuItem;
switch (sortOrder) {
  case 0:
    menuItem = popupMenu.getMenu().findItem(R.id.menu_item_0);
    break;
  case 1:
    menuItem = popupMenu.getMenu().findItem(R.id.menu_item_1);
    break;
  case 2:
    menuItem = popupMenu.getMenu().findItem(R.id.menu_item_2);
    break;
}
menuItem.setChecked();

第三，在菜单点击回调中更新当前排序顺序的值：

sortOrder = newSortOrder;

这样当弹出窗口再次打开时，第二步将确保已经检查了当前的排序顺序。

Answer 2

这里是我找到的两个选项菜单项的解决方案，你想用菜单和group.working 100％

包装它

将这两个项目添加到android：orderInCategory =＆＃34; 1＆＃34;对于第一项和android：orderInCategory =＆＃34; 2＆＃34;第二项

Answer 3

    private static void DownloadLargeFile()
    {
        var account = new CloudStorageAccount(new StorageCredentials(accountName, accountKey), true);
        var blobClient = account.CreateCloudBlobClient();
        var container = blobClient.GetContainerReference("container-name");
        var file = "my-very-large-file-name";
        var blob = container.GetBlockBlobReference(file);
        //First fetch the size of the blob. We use this to create an empty file with size = blob's size
        blob.FetchAttributes();
        var blobSize = blob.Properties.Length;
        long blockSize = (1 * 1024 * 1024);//1 MB chunk;
        blockSize = Math.Min(blobSize, blockSize);
        //Create an empty file of blob size
        using (FileStream fs = new FileStream(file, FileMode.Create))//Create empty file.
        {
            fs.SetLength(blobSize);//Set its size
        }
        var blobRequestOptions = new BlobRequestOptions
        {
            RetryPolicy = new ExponentialRetry(TimeSpan.FromSeconds(5), 3),
            MaximumExecutionTime = TimeSpan.FromMinutes(60),
            ServerTimeout = TimeSpan.FromMinutes(60)
        };
        long currentPointer = 0;
        long bytesRemaining = blobSize;
        do
        {
            var bytesToFetch = Math.Min(blockSize, bytesRemaining);
            using (MemoryStream ms = new MemoryStream())
            {
                //Download range (by default 1 MB)
                blob.DownloadRangeToStream(ms, currentPointer, bytesToFetch, null, blobRequestOptions);
                ms.Position = 0;
                var contents = ms.ToArray();
                using (var fs = new FileStream(file, FileMode.Open))//Open that file
                {
                    fs.Position = currentPointer;//Move the cursor to the end of file.
                    fs.Write(contents, 0, contents.Length);//Write the contents to the end of file.
                }
                currentPointer += contents.Length;//Update pointer
                bytesRemaining -= contents.Length;//Update bytes to fetch
            }
        }
        while (bytesRemaining > 0);
    }

MenuItem setChecked（）不起作用

3 个答案: