Question

我试图设置一个叠加片段，该片段会在触摸按钮时出现，并在再次单击该按钮时消失。我没有使用支持库片段，而是常规类型。因此，当您单击按钮以附加片段时，它会这样做，这里是代码：

boolean hasNativeFrag = false;
boolean isNativeFragShown = false;

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();


    if (id == R.id.native_chat) {
        Log.v("NativeChat", "NativeChat");

        //Instantiate fragment
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        NativeFragment nativeFragment = new NativeFragment();


        //Show/Hide

        if (isNativeFragShown) {
            fragmentTransaction.hide(nativeFragment);
            Log.d("Hidden", "Hidden");
            isNativeFragShown = false;

        } else {
            fragmentTransaction.show(nativeFragment);
            Log.d("Shown", "Shown");
            isNativeFragShown = true;
        }

        //Add/remove fragment
        if (!hasNativeFrag) {
            getFragmentManager().executePendingTransactions();
            fragmentTransaction.add(R.id.FragmentContainer, nativeFragment);
            isNativeFragShown = true;
            hasNativeFrag = true;
        }
        fragmentTransaction.commit();

    } else if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

但是当我再次点击该按钮时，我希望if条件能够运行，因为它现在可见了，它应该隐藏它。然而，nativeFragment.isVisible（）始终返回false。我做错了什么？

非常感谢

更新1：无法使用答案提出的任何方法，但是一个简单的布尔值至少会在它们之间切换，如下所示：

# Special characters - dollar signs, spaces inside of quotes, etc. -
# should be escaped with a single backslash or can cause deploy failures.

server {
    listen      [::]:80;
    listen      80;
    server_name $NOSSL_SERVER_NAME;
    access_log  /var/log/nginx/${APP}-access.log;
    error_log   /var/log/nginx/${APP}-error.log;

    # set a custom header for requests
    # add_header X-Served-By www-ec2-01;

    location    / {
      proxy_pass  http://$APP;
      proxy_http_version 1.1;
      proxy_set_header Upgrade \$http_upgrade;
      proxy_set_header Connection "upgrade";
      proxy_set_header Host \$http_host;
      proxy_set_header X-Forwarded-Proto \$scheme;
      proxy_set_header X-Forwarded-For \$remote_addr;
      proxy_set_header X-Forwarded-Port \$server_port;
      proxy_set_header X-Request-Start \$msec;
    }

    include $DOKKU_ROOT/$APP/nginx.conf.d/*.conf;

    # Proxy download 
    location ~* ^/internal_redirect/(.*?)/(.*) {
    # Do not allow people to mess with this location directly
    # Only internal redirects are allowed
    internal;

    # Location-specific logging
    access_log logs/internal_redirect.access.log main;
    error_log logs/internal_redirect.error.log warn;

    # Extract download url from the request
    set $download_uri \$2;
    set $download_host \$1;

    # Compose download url
    set $download_url http://\$download_host/\$download_uri;

    # Set download request headers
    proxy_set_header Host \$download_host;
    proxy_set_header Authorization '';

    # The next two lines could be used if your storage 
    # backend does not support Content-Disposition 
    # headers used to specify file name browsers use 
    # when save content to the disk
    proxy_hide_header Content-Disposition;
    add_header Content-Disposition 'attachment; filename="\$args"';

    # Do not touch local disks when proxying 
    # content to clients
    proxy_max_temp_file_size 0;

    # Download the file and send it to client
    proxy_pass \$download_url;
  }
}

日志说它在函数之间切换，这很好，但是片段仍然可见，即使在使用.hide后

我引用了错误的东西吗？

Answer 1

您可以使用以下方法getUserVisibleHint()来确定您的片段对用户是否可见

Answer 2

每次按下native_chat按钮时都会创建一个新片段，这个新片段在添加/显示之前永远不可见。尝试添加一个字段以保留此片段的引用，并确定已创建的字段的可见性。另外，我认为你想要一个if / else for action_settings按钮。

NativeFragment nativeFragment = null;

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == R.id.native_chat) {
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        if (nativeFragment == null) {
            // fragment doesn't exist, lets create and add one
            nativeFragment = new NativeFragment();
            getFragmentManager().executePendingTransactions();
            fragmentTransaction.add(R.id.FragmentContainer, nativeFragment);
        }

        if(nativeFragment.isVisible()){
            fragmentTransaction.hide(nativeFragment);
        } else {
            fragmentTransaction.show(nativeFragment);
        }
        fragmentTransaction.commit();

    } else if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

fragment.isVisible（）始终返回false

2 个答案: