findviewbyid在对话框中返回null [英] findviewbyid returns null in a dialog

问题描述

我有一个自定义对话框，当我尝试获取EditText的值时，它返回null。

I have a custom dialog and when I try to get the value of an EditText it returns null.

此行返回null

EditText et = (EditText)findViewById(R.id.username_edit);

以下是完整的代码。

protected Dialog onCreateDialog(int id) {
    switch (id) {
    case DIALOG_TEXT_ENTRY:
        LayoutInflater factory = LayoutInflater.from(this);
        final View textEntryView = factory.inflate(R.layout.alert_dialog_text_entry, null);
        return new AlertDialog.Builder(TicTacToe.this)
            //.setIconAttribute(android.R.attr.alertDialogIcon)
            .setTitle(getTitleText())
            .setView(textEntryView)
            .setPositiveButton("JOIN GAME", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    try
                    {
                        EditText et = (EditText)findViewById(R.id.username_edit);
                            playerName = et.getText().toString();
                    }
                    catch (Exception e)
                    {
                    }
                }
            })
            .create();
    }
    return null;
}

推荐答案

试试这个：

EditText et = (EditText)textEntryView.findViewById(R.id.username_edit);

你必须告诉在哪个视图中找到id。否则，它将尝试在 setContentView （通常在 onCreate 中声明）的xml布局中查找视图中的id

You have to tell in which view to find the id. Otherwise it will try to find the id in the view from the xml layout inflated by setContentView (usually declared in onCreate)

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