android - 根据点击使用合并和包含标签动态更改 UI

Question

我是 Android 和一般编程的新手，所以放轻松!

我创建了一个 - 可能过于复杂但它做了我想要的 - main.xml 我的布局是这样的:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/main_scrollview"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    >
<LinearLayout
    ...
    >
    <TextView  
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content" 
        android:text="@string/title"
        android:gravity="center"
    />
    <TableLayout
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:stretchColumns="0"
        >
        <TableRow>
            <TextView/>
            <Spinner/>
        </TableRow>
        <TableRow>
            <TextView/>
            <Spinner/>
        </TableRow>
    </TableLayout>
    <TableLayout
        android:id="@+id/main_tablelayout2"
        android:layout_width="fill_parent" 
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:stretchColumns="*"
        >
        <include
            android:id="@+id/include"
            layout="@layout/price0"
        />
        <TableRow>
            <TextView/>
            <EditText/>
        </TableRow>
    </TableLayout>
</LinearLayout>
</ScrollView>

这是我要包含的选项之一 (price1.xml):

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">
<TableRow>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="fill_parent"
        android:text="@string/price1"
        android:gravity="center_vertical"
    />
    <EditText
        android:id="@+id/price1"
    />
</TableRow> 
</merge>

我正在尝试根据其中一个微调器的值动态更改包含，但我在启动应用程序时强制关闭。

logcat 错误是:

01-18 15:31:42.826: ERROR/AndroidRuntime(719): FATAL EXCEPTION: main
01-18 15:31:42.826: ERROR/AndroidRuntime(719): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.view.ViewGroup.addViewInner(ViewGroup.java:1976)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.view.ViewGroup.addView(ViewGroup.java:1871)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.widget.TableLayout.addView(TableLayout.java:421)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.view.ViewGroup.addView(ViewGroup.java:1828)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.widget.TableLayout.addView(TableLayout.java:403)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.view.ViewGroup.addView(ViewGroup.java:1808)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.widget.TableLayout.addView(TableLayout.java:394)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at com.kavi.eta.Calculate$1.onItemSelected(Calculate.java:36)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.widget.AdapterView.fireOnSelected(AdapterView.java:871)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.widget.AdapterView.access$200(AdapterView.java:42)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.widget.AdapterView$SelectionNotifier.run(AdapterView.java:837)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.os.Handler.handleCallback(Handler.java:587)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.os.Handler.dispatchMessage(Handler.java:92)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.os.Looper.loop(Looper.java:123)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at android.app.ActivityThread.main(ActivityThread.java:3647)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at java.lang.reflect.Method.invokeNative(Native Method)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at java.lang.reflect.Method.invoke(Method.java:507)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-18 15:31:42.826: ERROR/AndroidRuntime(719):     at dalvik.system.NativeStart.main(Native Method)

看起来我做错了 java 代码，但我不知道如何正确删除默认包含并将其替换为另一个布局:

public void onItemSelected(AdapterView<?> arg0, View arg1, int position, long id) { 
            int index = formatSpinner.getSelectedItemPosition();
            if (index == 0) {

                TableLayout tl = (TableLayout)findViewById(R.id.main_tablelayout2);
                tl.removeView(findViewById(R.id.include));

                LayoutInflater inflater = getLayoutInflater();
                tl.addView(inflater.inflate(R.layout.price1, tl, true));
            }

很抱歉发了这么长的帖子，但我到处搜索都找不到明确的答案。希望这至少能提供一个像样的例子......

Answer 1

如果您尝试对包含的布局中存在的元素使用 findViewById()，您将得到 NullPointerException。它们不在 setContentView(View) 中添加的布局中，因此您必须在以下代码 fragment 中提供包含标签和 id，例如 includedLayout -

<include android:id="@+id/includedLayout" layout="@layout/yourLayout"/>

并使用普通的 findViewById() 调用找到它

ViewGroup includedLayout = (ViewGroup)findViewById(R.id.includedLayout);

然后使用此对象在包含的布局中查找 View 。

View myVIew = includedLayout.findViewById(R.id.myViewId);

虽然线程是旧的，但我想这个答案将帮助 future 的读者准确地找到他们的布局中发生了什么。