自定义 AlertDialog 的 EditText 值到 Textview

Question

我在这里发现了一些类似的问题，但它们要么让像我这样的新手感到困惑，要么无助于解决我的问题：我有一台 TextView 电视。通过单击它，我想显示带有 EditText + 取消和更新按钮的自定义 AlertDialog。通过单击我的对话框的更新按钮，我想用对话框中的 EditText 值替换同一 TextView (tv) 的文本。这是我的一项尝试：

...
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    final TextView tv̶̶C̶̶l̶̶i̶̶c̶̶k̶̶e̶̶d̶ = (TextView) findViewById(R.id.tv_id);
    tv.setText("Initial value");

    tv.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            UpdateDialogFragment updDiag = new UpdateDialogFragment();
            updDiag.show(getFragmentManager(), "dialog");
            tv.setText(updDiag.value); // I try to get the value of EditText like this, but it doesn't work
        }
        });
}

public class UpdateDialogFragment extends DialogFragment {
    String value; // I try to get the value of EditText like this, but it doesn't work
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        LayoutInflater inflater = getActivity().getLayoutInflater();

        builder.setView(inflater.inflate(R.layout.edit_tv, null))
                .setPositiveButton("Update", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {
                        EditText et = (EditText) UpdateDialogFragment.this.getDialog().findViewById(R.id.et_tv);
                        value = et.getText().toString();  // I try to get the value of EditText like this, but it doesn't work
                    }
                })
                .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        UpdateDialogFragment.this.getDialog().cancel();
                    }
                });
        return builder.create();
    }
}

还有我的edit_tv.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/et_tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:layout_marginTop="40dp"
        android:hint="Enter text ..."
        android:layout_gravity="center_horizontal">

        <requestFocus />
    </EditText>

</LinearLayout>

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.yev.tabletasting.MainActivity">

    <TextView
        android:id="@+id/tv_id"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />    

</RelativeLayout>

在我的例子中，点击 "Update" 后，tv 的文本将被设置为“”（可能为空）。我将感谢您的每一个建议，感谢您的期待！

Answer 1

这是你的 TextView onClickListener 中应该有的内容：

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Write new value for TextView");
final EditText editText = new EditText(this);
builder.setView(editText);
builder.setPositiveButton("Update", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {                 
                    }
                });
AlertDialog dialog = builder.create();
dialog.show();
dialog.getButton(DialogInterface.BUTTON_POSITIVE).setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        String newValue = editText.getText().toString();
                        if(newValue.lenght() == 0)
                            Toast.makeText(this, "You need to type something in the editText", Toast.LENGTH_LONG).show();
                        }else{
                            tv.setText(newValue);
                            dialog.dismiss();
                        }
                    });

可能需要做一些小改动，因为我在这里写下了代码。希望能帮助到你。祝你好运:)

LE：对话框编辑文本不需要额外的片段和 xml 文件。

Answer 2

好的，所以您并没有真正提到为什么您更喜欢使用 DialogFragment 而不是像 Victor Holotescu 回答的那样仅仅使用 AlertDialog。但是，我尝试了您的代码，并在尝试单击 更新按钮 时收到了 NullPointerException。于是看了看，修改了代码，这里是：

MainActivity

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final TextView tv = (TextView) findViewById(R.id.tv_id);
        tv.setText("Initial value");

        tv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                UpdateDialogFragment updDiag = new UpdateDialogFragment().newInstance(tv); // Passed the TextView here
                updDiag.show(getFragmentManager(), "dialog");
            }
        });
    }

    public static class UpdateDialogFragment extends DialogFragment {
        String value; // I try to get the value of EditText like this, but it doesn't work
        TextView tvToEdit;

        public UpdateDialogFragment newInstance(TextView tvToEdit){
            UpdateDialogFragment udf = new UpdateDialogFragment();
            udf.tvToEdit = tvToEdit;
            return udf;
        }

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
            LayoutInflater inflater = getActivity().getLayoutInflater();

            builder.setView(inflater.inflate(R.layout.edit_tv, null))
                    .setPositiveButton("Update", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int id) {
                            EditText et = (EditText) UpdateDialogFragment.this.getDialog().findViewById(R.id.et_tv);
                            value = et.getText().toString();
                            tvToEdit.setText(value);
                        }
                    })
                    .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int id) {
                            UpdateDialogFragment.this.getDialog().cancel();
                        }
                    });
            return builder.create();
        }
    }
}

我在代码中添加了一些 TODO 注释（标有 阅读下面的注释。:)），请查看。我测试了它并且它运行正常。希望这能够以某种方式帮助您。有关 AlertDialogs 和 DialogFragments 的更多信息，这里有一个很好的 post -- DialogFragment advantages over AlertDialog.

EDIT

好的。因此，我编辑了它，您只需通过创建一个 newInstance 方法将 TextView 传递给 UpdateDialogFragment——在此处引用它 SetText of TextView in DialogFragment from Calling Activity——希望这会有所帮助。 :)

自定义 AlertDialog 的 EditText 值到 Textview

EditText value of custom AlertDialog to Textview

android

textview

android-edittext

android-dialog

android-dialogfragment