findViewById() 对于对话框中的视图返回 null

问题是，无论我在哪里或如何调用此布局的组件，它们总是返回 null。

setView(inflater.inflate(R.layout.search_layout, null))

这很好用。它显示内部的布局Dialog，但是，子项始终返回为 nullfindViewById(R.id.some_search_layout_children).

我多次尝试清理我的项目，尝试为我的项目实现另一个类Dialog，称为findViewById()作为我的主要成员Activity， 在 - 的里面initSearch()方法，并在匿名实现中OnClickListener为了Dialog，但结果都相同。我也尝试过让孩子们独立Views 并以编程方式调用它们：

TextView text = (TextView) findResourceById(R.id.new_independant_textview);

但是，同样的结果。

这是相关代码：

public class Xyz extends Activity {
    public void onCreate(...) { // some listener will trigger initSearch() }

    private void initSearch() {
        AlertDialog.Builder searchDialog = new AlertDialog.Builder(this);
        LayoutInflater inflater = this.getLayoutInflater();
        searchDialog.setTitle("Search Photos");
        searchDialog.setMessage("Specify tag and value...");
        // R.layout.search_dialog is my custom layour, it displays fine, it works. 
        searchDialog.setView(inflater.inflate(R.layout.search_dialog, null));
        EditText tagText = (EdiText) findViewById(R.id.tagField); // WILL RETURN NULL
        searchDialog.setPositiveButton( ... ) ...
        searchDialog.show();
    }

这行：

 EditText text = (EditText) findViewById(R.id.tagField);

始终返回 null，无论如何或在何处调用 – 全局、本地final等等——它只是返回 null。

这是我的自定义 XMLDialog layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/search_dialog"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/tagText" 
        android:padding="7dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:text="@string/tag" />
    <EditText 
        android:id="@+id/tagField"
        android:padding="7dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="text"/>
    <TextView
        android:id="@+id/valueText" 
        android:padding="7dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:text="@string/value" />
    <EditText 
        android:id="@+id/valueField"
        android:padding="7dp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="text"/>
</LinearLayout>

这是我的R.java file:

public static final class id {
    public static final int action_settings=0x7f0a0011;
    public static final int add_album=0x7f0a0001;
    public static final int add_photo=0x7f0a000d;
    public static final int albums_list=0x7f0a0003;
    public static final int delete_album=0x7f0a000b;
    public static final int exit_finder=0x7f0a000f;
    public static final int new_directory=0x7f0a000e;
    public static final int open_album=0x7f0a000a;
    public static final int photos_grid=0x7f0a0000;
    public static final int rename_album=0x7f0a000c;
    public static final int search_dialog=0x7f0a0004;
    public static final int search_icon=0x7f0a0002;
    public static final int splash_rutgers=0x7f0a0009;
    public static final int tagField=0x7f0a0006; // problematic
    public static final int tagText=0x7f0a0005; / problematic
    public static final int terminate_app=0x7f0a0010;
    public static final int valueField=0x7f0a0008; // problematic
    public static final int valueText=0x7f0a0007; // problematic
}

Calling findViewById()将在您的范围内搜索视图活动的排版和not你的对话框的视图。你需要打电话findViewById()在具体的View您设置为对话框的布局。

Try this

private void initSearch() {
    AlertDialog.Builder searchDialog = new AlertDialog.Builder(this);
    LayoutInflater inflater = this.getLayoutInflater();
    searchDialog.setTitle("Search Photos");
    searchDialog.setMessage("Specify tag and value...");
    // R.layout.search_dialog is my custom layour, it displays fine, it works. 
    View dialogView = inflater.inflate(R.layout.search_dialog, null);
    searchDialog.setView(dialogView);
    EditText tagText = (EdiText) dialogView.findViewById(R.id.tagField); 
    searchDialog.setPositiveButton( ... ) ...
    AlertDialog myAlert = searchDialog.create(); //returns an AlertDialog from a Builder.
    myAlert.show();
}

请注意我如何膨胀视图并将其存储在View named dialogView。然后，找到你的EditText named tagField， 我在用着dialogView.findViewById(R.id.tagField);