Question

我有一个名为AuditQuestionEntry的子类，它扩展了LinearLayout。除了其他字段，此布局还包含一个按钮。在我的主要活动（“AuditActivity”）上，我有多个AuditQuestionEntry实例。从AuditActivity，我在每个AuditQuestionEntry布局中为按钮设置了一个OnClickListener。在OnClick方法中，我需要访问与单击的按钮关联的AuditQuestionEntry中的参数。

在OnClickListener中，我调用了getParent（），我可以将它转换为AuditQuestionEntry。但是，当我尝试从那里访问一个参数时，它返回null（或者在我的情况下为0，因为它是一个int）。基本上，似乎getParent（）返回的是该类的新实例，而不是包含该按钮的实际实例。

布局 - audit_question_entry.xml：

<TextView
    android:id="@+id/auditQuestion"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Audit Question..."
    android:textSize="20dp" />

<Button
    android:id="@+id/btnTakeAuditPhoto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Add Photo" >
</Button>

这是AuditQuestionEntry.java：

public class AuditQuestionEntry extends LinearLayout {

// Define controls
private TextView auditQuestion;
private RatingBar auditRating;
private EditText auditComment;
private ImageView imageView;
private Button photoButton;

private static final int CAMERA_REQUEST = 1888;
private static final int REQUEST_IMAGE_CAPTURE = 1;

public int AuditQuestionNumber; // NEED TO GET THIS!
private Context _ctx;

public ClosetAuditQuestionObj AuditQuestion;

private String PhotoFolder;
private String FullPhotoPathAndName;

public AuditQuestionEntry(Context context) {
    super(context);
    // InflateView();

    throw new RuntimeException("Valid AuditQuestionNumber must be passed to this class via the XML parameters: workbench:AuditQuestionNumber.");
}

public AuditQuestionEntry(Context context, AttributeSet attrs) {
    super(context, attrs);

    this._ctx = context;

    initAttributes(attrs);
}

// Used to grab the AuditQuestionNumber attribute from the XML declaration
// for this layout
private void initAttributes(AttributeSet attrs) {
    TypedArray a = _ctx.obtainStyledAttributes(attrs, R.styleable.AuditQuestionEntry);

    AuditQuestionNumber = attrs.getAttributeIntValue("http://schemas.android.com/apk/com.bc.workbench", "AuditQuestionNumber", 0);

    a.recycle();
}

Inside AuditActivity onCreate（）我有以下内容：

         OnClickListener btnPhotoListener = new OnClickListener() {

        @Override
        public void onClick(final View v) {

            View viewParent = (View) v.getParent();

            AuditQuestionEntry clickedAudit = (AuditQuestionEntry) viewParent;

            // On the following line, clickedAudit.AuditQuestionNumber is always 0 even though it was initialized and
            // displays properly on screen.
            Toast.makeText(CurrentContext, "Audit Question #" + clickedAudit.AuditQuestionNumber, Toast.LENGTH_SHORT).show();
        }

     };


        // Set event listener for photo buttons
        // =============================================
     ((Button) AuditQuestion1.findViewById(R.id.btnTakeAuditPhoto)).setOnClickListener(btnPhotoListener);
     ((Button) AuditQuestion2.findViewById(R.id.btnTakeAuditPhoto)).setOnClickListener(btnPhotoListener);

Answer 1

在XML中，您在哪里设置AuditQuestionNumber的属性？如果用于给类膨胀的XML不包含属性，则构造函数将class属性的值默认为0：

AuditQuestionNumber = attrs.getAttributeIntValue("http://schemas.android.com/apk/com.bc.workbench", "AuditQuestionNumber", 0);

从Button Click访问LinearLayout子类参数

1 个答案: