java - DialogFragment 上的标题

Question

我想创建一个简单的对话框，中间有一个 GridView ，让用户选择一个字母。

这是我开始的 XML:https://developer.android.com/guide/topics/ui/layout/gridview.html和其他一些:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content">
    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/gridview"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:columnWidth="90dp"
              android:numColumns="auto_fit"
              android:verticalSpacing="10dp"
              android:horizontalSpacing="10dp"
              android:stretchMode="columnWidth"
              android:gravity="center"
        />
</LinearLayout>

然后我有这个代码来使用它:

package com.example.activity;

import android.app.Dialog;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.DialogFragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;

/**
 * Select a letter from the dialog
 */
public class SelectLetterDialogFragment extends DialogFragment {
    GridView gridView;

    static final String[] numbers = new String[] {
            "A", "B", "C", "D", "E",
            "F", "G", "H", "I", "J",
            "K", "L", "M", "N", "O",
            "P", "Q", "R", "S", "T",
            "U", "V", "W", "X", "Y", "Z"};

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Dialog dialog = super.onCreateDialog(savedInstanceState);
        dialog.setTitle("Select a letter");

        return dialog;
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
        final View view = inflater.inflate(R.layout.select_letter_dialog, container);

        gridView = (GridView) view.findViewById(R.id.gridview);

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(view.getContext(), android.R.layout.simple_list_item_1, numbers);

        gridView.setAdapter(adapter);
        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v,
                                    int position, long id) {
                String letter = ((TextView) v).getText().toString();
                Log.e("Blah", letter);
                dismiss();
            }
        });

        setStyle(STYLE_NORMAL, android.R.style.Theme_Holo_Dialog);

        return  view;
    }
}

因此，这将创建一个只有一个带有字母的网格的对话框。这让我很困惑。所以第一个问题是，既然 dialog.setTitle("Select a letter") 似乎对此没有影响，它会做什么？

然后我更改了 XML 文件以添加 TextView 以将标题放入其中，如下所示:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content">
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Select a Letter"
        />
    <GridView xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/gridview"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:columnWidth="90dp"
              android:numColumns="auto_fit"
              android:verticalSpacing="10dp"
              android:horizontalSpacing="10dp"
              android:stretchMode="columnWidth"
              android:gravity="center"
        />
</LinearLayout>

现在这些字母位于一列中。所以我的第二个问题是，WTF？为什么会这样？

我的第三个也是真正的问题是如何在对话框中获得一个标题，其中字母四横穿网格，就像第一个示例一样？

Answer 1

如onCreateDialog的注释: 我想你可以尝试将onCreateView中的代码移至onCreateDialog，然后删除onCreateView。像这样:

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    Dialog dialog = super.onCreateDialog(savedInstanceState);
    dialog.setContentView(R.layout.select_letter_dialog);
    dialog.setTitle("Select a letter");
    gridView = (GridView) dialog .findViewById(R.id.gridview);

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(view.getContext(), android.R.layout.simple_list_item_1, numbers);

    gridView.setAdapter(adapter);
    gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View v,
                                int position, long id) {
            String letter = ((TextView) v).getText().toString();
            Log.e("Blah", letter);
            dismiss();
        }
    });

    setStyle(STYLE_NORMAL, android.R.style.Theme_Holo_Dialog);

    return  dialog;
}