我正在尝试将CustomViewBeta(一个扩展的RelativeLayout)添加到CustomViewAlpha(一个扩展的LinearLayout)中,目的是让CustomViewAlpha像ListView一样容纳许多个CustomViewBeta。不管我尝试什么方法,都无法实现。我要么看不见任何CustomViewBetas,要么在我尝试在CustomViewBeta内部的TextView上setText时出现NPE错误。
我通常会在“textView.setText(”ASDASDASDAD“);”这一行上遇到NPE,因为TextView为空。我是否遗漏了什么?我不应该尝试为CustomViewBeta填充XML,而只是通过编程方式来完成它(逐个添加TextView)吗?谢谢。
CustomViewAlpha正常工作,因为它在Fragment的XML中被硬编码:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
...>
<com.path.CustomViewAlpha
android:id="@+id/customviewalpha"
android:orientation="vertical"
android:layout_gravity="center_vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</FrameLayout>
代码如下:
public class CustomViewAlpha extends LinearLayout {
private Context mContext;
public CustomViewAlpha (Context context) {
super(context);
this.mContext = context;
}
public CustomViewAlpha (Context context, AttributeSet attrs) {
super(context, attrs);
this.mContext = context;
}
public CustomViewAlpha (Context context, AttributeSet attrs, int defStyle){
super(context, attrs,defStyle);
this.mContext = context;
}
public void addCustomViewBeta(String someString){
CustomViewBeta customViewBeta = new CustomViewBeta(mContext);
addView(customViewBeta);
}
CustomViewBeta 不是在 Fragment 的 XML 中硬编码的,而是通过编程方式添加:
public class CustomViewBeta extends RelativeLayout{ private Context mContext;
private TextView textView;
public CustomViewBeta (Context context) {
super(context);
this.mContext = context;
init();
}
public CustomViewBeta (Context context, AttributeSet attrs) {
super(context, attrs);
this.mContext = context;
init();
}
public CustomViewBeta (Context context, AttributeSet attrs, int defStyle){
super(context, attrs,defStyle);
this.mContext = context;
init();
}
private void init() {
LayoutInflater.from(mContext).inflate(R.layout.customviewbeta, null, false);
textView = (TextView) findViewById(R.id.tripleexpandablelistview_category_name);
textView.setText("ASDASDASDAD");
}
以下是XML示例:
<?xml version="1.0" encoding="utf-8"?>
<com.path.CustomViewBeta
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/customviewbeta_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</com.path.CustomViewBeta>
我通常会在“textView.setText(”ASDASDASDAD“);”这一行上遇到NPE,因为TextView为空。我是否遗漏了什么?我不应该尝试为CustomViewBeta填充XML,而只是通过编程方式来完成它(逐个添加TextView)吗?谢谢。