如何填充这是在android的按钮，点击动态生成一个微调 [英] How to populate a spinner which is dynamically generated on click of button in android
问题描述
的我正在寻找如何在Android的添加/删除布局动态按钮的点击发现的的这个。
我用codeS上面提到的教程和设计产生按钮的每次点击一个布局的页面。此布局包含微调，的EditText ＆安培; 按钮。
I used the codes from above mentioned tutorial and designed a page which generates a layout on every click of button. This layout contains a Spinner, EditText & Button.
的我的code成功地增加了/删除按钮单击布局。的
所以我的第一个问题是所有生成的微调都是空的，即它们不与填充数据从数据库之后，他们的创作和第二个问题是，我怎么能获取所选/进入，从动态创建的微调数据/作为的EditText我不知道他们的ID。
的的 DBHelper 类正常工作与我的其他应用程序，所以我没有在这里张贴。的
The DBHelper class works fine with my other apps so I haven't posted it here.
这是 MyLayoutOperation 类： -
This is the MyLayoutOperation class:-
public class MyLayoutOperation extends Activity {
static Spinner s;
public static void display(final Activity activity, Button btn)
{
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
LinearLayout scrollViewlinerLayout = (LinearLayout) activity.findViewById(R.id.linearLayoutForm);
java.util.ArrayList<String> msg = new ArrayList<String>();
for (int i = 0; i < scrollViewlinerLayout.getChildCount(); i++)
{
LinearLayout innerLayout = (LinearLayout) scrollViewlinerLayout.getChildAt(i);
s = (Spinner) innerLayout.findViewById(R.id.spinner1);
EditText edit = (EditText) innerLayout.findViewById(R.id.editDescricao);
//msg.add(products.getSelectedItem().toString());
msg.add(edit.getText().toString());
}
Toast t = Toast.makeText(activity.getApplicationContext(), msg.toString(), Toast.LENGTH_SHORT);
t.show();
}
});
}
public static void add(final Activity activity, ImageButton btn)
{
final LinearLayout linearLayoutForm = (LinearLayout) activity.findViewById(R.id.linearLayoutForm);;
btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final LinearLayout newView = (LinearLayout)activity.getLayoutInflater().inflate(R.layout.rowdetail, null);
newView.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
ImageButton btnRemove = (ImageButton) newView.findViewById(R.id.btnRemove);
btnRemove.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
linearLayoutForm.removeView(newView);
}
});
linearLayoutForm.addView(newView);
}
});
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.rowdetail);
s = (Spinner) findViewById(R.id.spinner1);
// Loading spinner data from database
try {
loadSpinnerData();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void loadSpinnerData() throws IOException {
// database handler
DBHelper db = new DBHelper(getApplicationContext());
// Spinner Drop down elements
List<String> products = db.getAllProducts();
// Creating adapter for spinner
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, products);
// Drop down layout style - list view with radio button
dataAdapter
.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// attaching data adapter to spinner
s.setAdapter(dataAdapter);
}
}
LogCat中： -
LogCat:-
07-22 08:23:27.090: E/AndroidRuntime(1834): FATAL EXCEPTION: main
07-22 08:23:27.090: E/AndroidRuntime(1834): Process: com.example.teste1, PID: 1834
07-22 08:23:27.090: E/AndroidRuntime(1834): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.teste1/com.example.teste1.MainActivity}: java.lang.NullPointerException
07-22 08:23:27.090: E/AndroidRuntime(1834): Caused by: java.lang.NullPointerException
07-22 08:23:27.090: E/AndroidRuntime(1834): at com.example.teste1.MyLayoutOperation.add(MyLayoutOperation.java:73)
07-22 08:23:27.090: E/AndroidRuntime(1834): at com.example.teste1.MainActivity.onCreate(MainActivity.java:22)
07-22 08:23:27.090: E/AndroidRuntime(1834): at android.app.Activity.performCreate(Activity.java:5231)
的线73 MyLayoutOperation ： - btn.setOnClickListener（新View.OnClickListener（）{
Line 73 of MyLayoutOperation :- btn.setOnClickListener(new View.OnClickListener() {
的线22 MainActivity ： - MyLayoutOperation.add（这一点，btnAdd）;
Line 22 of MainActivity :- MyLayoutOperation.add(this, btnAdd);
MainActivity.java ： -
MainActivity.java :-
public class MainActivity extends Activity {
Button btnDisplay;
ImageButton btnAdd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnAdd = (ImageButton) findViewById(R.id.btnAdd);
btnDisplay = (Button) findViewById(R.id.btnDisplay);
MyLayoutOperation.add(this, btnAdd);
MyLayoutOperation.display(this, btnDisplay);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
rowdetail.xml ： -
rowdetail.xml :-
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/rowdetail"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<Spinner
android:id="@+id/spinner1"
android:layout_width="94dp"
android:layout_height="45dp" />
<EditText
android:id="@+id/editDescricao"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="0.01"
android:ems="10"
android:inputType="text" />
<ImageButton
android:id="@+id/btnRemove"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:contentDescription="@string/btnRemove"
android:src="@android:drawable/ic_delete" />
</LinearLayout>
activity_main.xml中： -
activity_main.xml :-
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/layoutTeste"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
tools:context=".MainActivity" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/textView1"
android:layout_width="95dp"
android:layout_height="fill_parent"
android:layout_alignBottom="@+id/btnAdd"
android:layout_alignParentLeft="true"
android:layout_toLeftOf="@+id/btnAdd"
android:gravity="center_vertical|center_horizontal"
android:text="@string/titleTecnologies"
android:textAppearance="?android:attr/textAppearanceLarge" />
<ImageButton
android:id="@+id/btnAdd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:contentDescription="@string/btnAdd"
android:src="@android:drawable/ic_input_add" />
</RelativeLayout>
<ScrollView
android:id="@+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="275dp" >
<LinearLayout
android:id="@+id/linearLayoutForm"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>
</ScrollView>
<Button
android:id="@+id/btnDisplay"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/btnDisplay" />
</LinearLayout>
请帮忙。
推荐答案
编辑：
你不需要你的额外活动。你只需要一个活动，这将显示您的布局，并更新在你按一下按钮。
You don't need your extra activity. You simply need one activity, that will display your layout, and update it on your button click.
public class TestActivity extends Activity {
Button btnDisplay;
ImageButton btnAdd;
LinearLayout container;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
container = findViewById(R.id.linearLayoutForm);
btnAdd = (ImageButton) findViewById(R.id.btnAdd);
btnDisplay = (Button) findViewById(R.id.btnDisplay);
btnAdd.setOnClickListener(addListener);
//TODO: btnDisplay
}
/*
* We define our OnClickListener that will act when we click on the btn.
*/
View.OnClickListener addListener = new View.OnClickListener() {
@Override
public void onClick(View v) {
final LinearLayout newView = (LinearLayout) getLayoutInflater().inflate(R.layout.rowdetail, null);
newView.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
ImageButton btnRemove = (ImageButton) newView.findViewById(R.id.btnRemove);
btnRemove.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
container.removeView(newView);
}
});
container.addView(newView);
//Now we load your data into your spinner
Spinner s = newView.findViewById(R.id.spinner1);
try {
loadSpinnerData(s);
} catch (IOException e) {
//TODO: catch exception
e.printStackTrace();
}
}
};
/*
* This function is supposed to load the data into the given spinner.
* It would be better to load the data an other way, i.e.: using ASyncTask
*/
private void loadSpinnerData(Spinner s) throws IOException {
// database handler
DBHelper db = new DBHelper(getApplicationContext());
// Spinner Drop down elements
List<String> products = db.getAllProducts();
// Creating adapter for spinner
ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item, products);
// Drop down layout style - list view with radio button
dataAdapter
.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// attaching data adapter to spinner
s.setAdapter(dataAdapter);
}
}
我没有测试此code，所以你可能因此它符合你的需求来调整它，但我认为主要的想法是存在的。
您的活动的onCreate膨胀布局。在那里你设定按钮，保存你的容器。
I haven't tested this code, so you might have to tweak it so it matches your needs, but I think the main idea is there. Your activity's onCreate inflates your layout. In there you set your button, and save information about your "container".
在点击您的添加按钮，您只需抬高新的布局，并使用设置微调数据的 loadSpinnerData（S）; ，它从数据库加载数据到你的微调。
On click on your add button, your simply inflate your new layout, and set your spinner data using your loadSpinnerData(s);, which loads the data from the database into your spinner.
请注意，这是没有得到从数据库中的信息的一个好方法。这样做可以阻止UI线程为获取大量的信息可能会非常耗时。这是更好地使用加载器，或AsyncTask的这样做。我也可以把你 Vogella教程，解释得非常好（而且很容易明白）如何有效地管理数据库中。
Note that it is not a good way of getting the information from the database. Doing so can block the UI thread as retrieving lots of information can be time consuming. It's better to use a loader, or an asynctask to do so. I can redirect you to Vogella tutorials that explains very well (and is very easy to understand) how to manage a database efficiently.
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