我不知道如何在我的自定义对话框中获取我的 EditText 的值

Question

我必须在 Android 上为一个学校项目做一个小应用程序，我想通过全屏对话框更新我的 listView，但我找不到一种方法来获取我的 EditText 字段中的值以将它们添加到我的 ArrayLists。

这是我的 Dialog 类的代码：

package com.example.memo;

import android.annotation.SuppressLint;

import android.os.Bundle;

import android.support.annotation.NonNull;

import android.support.annotation.Nullable;

import android.support.v4.app.DialogFragment;

import android.view.LayoutInflater;

import android.view.View;

import android.widget.EditText;

import android.view.ViewGroup;

import android.widget.ImageButton;

import android.widget.TextView;

import java.util.ArrayList;

@SuppressLint("ValidFragment")

public class FullscreenDialog extends DialogFragment implements View.OnClickListener {

    private EditText titleEdit;

    private EditText infoEdit;

    private EditText fullEdit;

    private ArrayList<String> titleArray;

    private ArrayList<String> infoArray;

    private ArrayList<Integer> imageArray;

    private ArrayList<String> fullArray;

    private Callback callback;

    public FullscreenDialog(ArrayList<String> titleArray, ArrayList<String> infoArray, ArrayList<String> fullArray, ArrayList<Integer> imageArray){

        this.titleArray = titleArray;

        this.infoArray = infoArray;

        this.fullArray = fullArray;

        this.imageArray = imageArray;

    }

    static FullscreenDialog newInstance(ArrayList<String> titleArray, ArrayList<String> infoArray, ArrayList<String> fullArray, ArrayList<Integer> imageArray) {

        return new FullscreenDialog(titleArray,infoArray,fullArray,imageArray);

    }

    public void setCallback(Callback callback) {

        this.callback = callback;

    }

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setStyle(DialogFragment.STYLE_NORMAL, R.style.FullscreenDialogTheme);

    }

  

} 

我想我在使用 findViewById 或其他东西的方式上一定犯了一些错误，但 Android 对我来说有点新，我似乎无法找到错误的地方。

titleArray、infoArray 和 fullArray 是存储我的数据的 ArrayList。

imageArray 是我的图像 ID 的 ArrayList。

Answer 1

您调用或使用未初始化的实例变量（即 fullEdit、titleEdit 等）。为了纠正这个在方法 onCreateView 中初始化它们，所以它应该看起来像这样@Nullable&nbsp; &nbsp; @Override&nbsp; &nbsp; public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {&nbsp; &nbsp; &nbsp; &nbsp; View view = inflater.inflate(R.layout.activity_fullscreen_dialog, container, false);&nbsp; &nbsp; &nbsp; &nbsp; ImageButton close = view.findViewById(R.id.fullscreen_dialog_close);&nbsp; &nbsp; &nbsp; &nbsp; TextView action = view.findViewById(R.id.fullscreen_dialog_action);&nbsp; &nbsp; &nbsp; &nbsp; titleEdit = view.findViewById(R.id.fullscreen_dialog_title);&nbsp; &nbsp; &nbsp; &nbsp; infoEdit = view.findViewById(R.id.fullscreen_dialog_info);&nbsp; &nbsp; &nbsp; &nbsp; fullEdit = view.findViewById(R.id.fullscreen_dialog_full);&nbsp; &nbsp; &nbsp; &nbsp; close.setOnClickListener(this);&nbsp; &nbsp; &nbsp; &nbsp; action.setOnClickListener(this);&nbsp; &nbsp; &nbsp; &nbsp; return view;&nbsp; &nbsp; }用上面的类实例 EditText 变量被实例化并且可以用来获取文本的 onClick 方法

Answer 2

您在类中全局定义变量 titleEdit、infoEdit 和 full Edit&nbsp;，但问题是您在 onCreateView 方法中再次在本地定义它们，并使用 findViewById 将它们分配给视图。所以你现在有两种变量：全球的（尚未链接）本地的（链接到视图）当您尝试获取未链接到 View 的全局值时，您访问的 editText 的值。为了解决这个问题，删除本地的。你 onCreateView 应该是这样的：@Nullable&nbsp; &nbsp; @Override&nbsp; &nbsp; public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {&nbsp; &nbsp; &nbsp; &nbsp; View view = inflater.inflate(R.layout.activity_fullscreen_dialog, container, false);&nbsp; &nbsp; &nbsp; &nbsp; ImageButton close = view.findViewById(R.id.fullscreen_dialog_close);&nbsp; &nbsp; &nbsp; &nbsp; TextView action = view.findViewById(R.id.fullscreen_dialog_action);&nbsp; &nbsp; &nbsp; &nbsp; titleEdit = view.findViewById(R.id.fullscreen_dialog_title);&nbsp; &nbsp; &nbsp; &nbsp; infoEdit = view.findViewById(R.id.fullscreen_dialog_info);&nbsp; &nbsp; &nbsp; &nbsp; fullEdit = view.findViewById(R.id.fullscreen_dialog_full);&nbsp; &nbsp; &nbsp; &nbsp; close.setOnClickListener(this);&nbsp; &nbsp; &nbsp; &nbsp; action.setOnClickListener(this);&nbsp; &nbsp; &nbsp; &nbsp; return view;&nbsp; &nbsp; }