如何使用EditText中的用户输入更新微调器的字段 [英] How can i update a field of my spinner with user input in EditText
本文介绍了如何使用EditText中的用户输入更新微调器的字段的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个SQLite数据库，用于填充我的微调器. 添加"功能运行良好！我想做的是，当用户单击微调器项目时，他可以更改以下字段并在数据库中更新
我的Spinner数据库
public class SpinnerDatabase extends SQLiteOpenHelper{
private SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "spinnerDB";
private static final String TABLE_LABELS = "labels";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
public SpinnerDatabase(Context context) {
super(context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CATEGORIES_TABLES = "CREATE TABLE " +
TABLE_LABELS + "(" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"+
KEY_NAME + " TEXT)";
db.execSQL(CREATE_CATEGORIES_TABLES);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);
onCreate(db);
}
public void insertLabel(String label){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME,label);
db.insert(TABLE_LABELS,null,values);
db.close();
}
public List<String> getAllLabels(){
List<String> labels = new ArrayList<String>();
String selectQuery = "SELECT * FROM "+ TABLE_LABELS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery,null);
if (cursor.moveToFirst()){
do{
labels.add(cursor.getString(1));
}while (cursor.moveToNext());
}
cursor.close();
db.close();
return labels;
}
public void updateSpinner (int id, String label){
ContentValues values;
String where;
db = this.getWritableDatabase();
where = KEY_ID + " = " +id;
values = new ContentValues();
values.put(KEY_NAME,label);
db.update(TABLE_LABELS,values,where,null);
db.close();
}
}
问题是当我单击按钮进行更新时，它什么都没做！并更新另一项(如果我还有更多的话). 这是我在片段中列出所有条目的方法:
private void loadSpinnerData (){
SpinnerDatabase db = new SpinnerDatabase(getActivity().getApplicationContext());
List<String> labels = db.getAllLabels();
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity().getApplicationContext(),
android.R.layout.simple_spinner_item,labels);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
}
在这里，按钮保存为我正在尝试进行更新:
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String name = editText.getText().toString();
if(name.length()>0 && name != null){
int spinnerValue = spinner.getSelectedItemPosition();
SpinnerDatabase db = new SpinnerDatabase(getActivity().getApplicationContext());
db.updateSpinner(spinnerValue,name);
}
});
解决方案
您的问题是，您正在使用微调框的选定位置(0、1,2等)作为行的ID. 可能是，但并非完全正确，即出于某种原因删除一行，并且序列中有间隔 . >
因此，您当前所遇到的是行ID和微调器位置之间的差为1，因此没有任何更新或正在更新另一行.
您要么需要采用某种方法来计算行ID到微调框的位置(例如，具有与第一个数组相同的索引的相应ID的第二个数组)，或者要做的是CursorAdpater(例如SimpleCursorAdapter)的灵活性的优势，然后使用spinner.getSelectedItemId()代替spinner.getSelectedItemPosition().
要使用CursorAdapter，您将需要一个名为 _id 的行(例如，将private static final String KEY_ID = "id";更改为public static final String KEY_ID = "_id";)
注意！如上所述，我还建议将您的private statics更改为public statics).
要使用CursorAdapter，您还需要一个Cursor. SpinnerDatabase.java中的以下方法就足够了.
public Cursor getAll() {
db = this.getWritableDatabase();
return db.query(TABLE_LABELS,null,null,null,null,null,null);
}
以下内容可用于设置adpater:-
csr = dbhlpr.getAll();
sca = new SimpleCursorAdapter(this,
android.R.layout.simple_list_item_1,
csr,
new String[]{SpinnerDatabase.KEY_NAME},
new int[]{android.R.id.text1},0);
spinner.setAdapter(sca);
注意！使用SpinnerDatabase.KEY_NAME，这就是为什么我建议使用公共静态"而不是private static的一个示例.
SimpleCursorAdpater有一些细微差别；
- 第3 个参数是光标
- 4th 是要显示的光标中的列名称的String数组(应与第5个参数匹配)，
- 第5 位是数据放置视图的ID.(对于simple_list_item_1，请使用1列名以及上述的android.R.id.text1).
，当涉及更新时，请使用 spinner.getSelectedItemId() 作为行ID.
工作示例(假设行中有数据)
SpinnerDatabase.java
public class SpinnerDatabase extends SQLiteOpenHelper {
private SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "spinnerDB";
private static final String TABLE_LABELS = "labels";
private static final String KEY_ID = "_id";
public static final String KEY_NAME = "name";
public SpinnerDatabase(Context context) {
super(context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CATEGORIES_TABLES = "CREATE TABLE " +
TABLE_LABELS + "(" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"+
KEY_NAME + " TEXT)";
db.execSQL(CREATE_CATEGORIES_TABLES);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);
onCreate(db);
}
public void insertLabel(String label){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME,label);
db.insert(TABLE_LABELS,null,values);
}
//Defunct
public List<String> getAllLabels(){
List<String> labels = new ArrayList<String>();
String selectQuery = "SELECT * FROM "+ TABLE_LABELS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery,null);
if (cursor.moveToFirst()){
do{
labels.add(cursor.getString(1));
}while (cursor.moveToNext());
}
cursor.close();
return labels;
}
public void updateSpinner (long id, String label){
ContentValues values;
String where;
db = this.getWritableDatabase();
where = KEY_ID + " = " +id;
values = new ContentValues();
values.put(KEY_NAME,label);
db.update(TABLE_LABELS,values,where,null);
db.close();
}
public Cursor getAll() {
db = this.getWritableDatabase();
return db.query(TABLE_LABELS,null,null,null,null,null,null);
}
}
活动 SO46330096Activity.java
public class SO46330096Activity extends AppCompatActivity {
SpinnerDatabase dbhlpr;
Spinner spinner;
Button editbutton;
EditText spinneritem;
SimpleCursorAdapter sca;
Cursor csr;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_so46330096);
spinner = (Spinner) findViewById(R.id.spinner);
editbutton = (Button) findViewById(R.id.editbutton);
spinneritem = (EditText) findViewById(R.id.spinnerinput);
dbhlpr = new SpinnerDatabase(this);
csr = dbhlpr.getAll();
sca = new SimpleCursorAdapter(this,
android.R.layout.simple_list_item_1,
csr,
new String[]{SpinnerDatabase.KEY_NAME},
new int[]{android.R.id.text1},0);
spinner.setAdapter(sca);
editbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (spinneritem.getText().toString().length() > 0) {
dbhlpr.updateSpinner(spinner.getSelectedItemId(),spinneritem.getText().toString());
sca.swapCursor(csr = dbhlpr.getAll());
}
}
});
}
}
布局 activity_so46330096.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SO463300096 Activity"/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="SPINNER ENTRY"
/>
<EditText
android:id="@+id/spinnerinput"
android:layout_width="0dp"
android:layout_weight="3"
android:layout_height="match_parent" />
<Button
android:id="@+id/editbutton"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="EDIT"/>
</LinearLayout>
<Spinner
android:id="@+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</Spinner>
</LinearLayout>
示例用法:-
已选择微调(已经输入了注释更新数据):-
选择花生酱并输入更新的数据:-
点击编辑"按钮后:-
将EditText设置为当前选定的Spinner Item
以下内容可用于将EditText设置为当前选定的微调器项目的值:-
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
spinneritem.setText(csr.getString(csr.getColumnIndex(SpinnerDatabase.KEY_NAME)));
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
可以在活动"中设置适配器后添加.
在上面的 SO46330096Activity.java 中，它可以遵循以下步骤:-
spinner.setAdapter(sca);
I have a SQLite Database with is populating my Spinner. The "add" functionality it's working good! What I wanna do is when user clicks in on spinner item he can change the following field and update in the Database
My Spinner database
public class SpinnerDatabase extends SQLiteOpenHelper{
private SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "spinnerDB";
private static final String TABLE_LABELS = "labels";
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
public SpinnerDatabase(Context context) {
super(context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CATEGORIES_TABLES = "CREATE TABLE " +
TABLE_LABELS + "(" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"+
KEY_NAME + " TEXT)";
db.execSQL(CREATE_CATEGORIES_TABLES);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);
onCreate(db);
}
public void insertLabel(String label){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME,label);
db.insert(TABLE_LABELS,null,values);
db.close();
}
public List<String> getAllLabels(){
List<String> labels = new ArrayList<String>();
String selectQuery = "SELECT * FROM "+ TABLE_LABELS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery,null);
if (cursor.moveToFirst()){
do{
labels.add(cursor.getString(1));
}while (cursor.moveToNext());
}
cursor.close();
db.close();
return labels;
}
public void updateSpinner (int id, String label){
ContentValues values;
String where;
db = this.getWritableDatabase();
where = KEY_ID + " = " +id;
values = new ContentValues();
values.put(KEY_NAME,label);
db.update(TABLE_LABELS,values,where,null);
db.close();
}
}
The problem is when I click the button to update, it doesn't do anything! And just update the other item (if I have more the one). This is my method in my fragment that list all the entries:
private void loadSpinnerData (){
SpinnerDatabase db = new SpinnerDatabase(getActivity().getApplicationContext());
List<String> labels = db.getAllLabels();
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity().getApplicationContext(),
android.R.layout.simple_spinner_item,labels);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
}
And here the button save that i'm trying to do the update:
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String name = editText.getText().toString();
if(name.length()>0 && name != null){
int spinnerValue = spinner.getSelectedItemPosition();
SpinnerDatabase db = new SpinnerDatabase(getActivity().getApplicationContext());
db.updateSpinner(spinnerValue,name);
}
});
解决方案
Your issue, is that you are using the Spinner's selected position (0,1,2 etc) as the row's id. The first row id will be 1, then 2, etc (probably but NOT CERTAINLY i.e. delete a row for some reason and you have a gap in the sequence).
As such what you are currently experiencing is a difference of 1 between row id and spinner position, so either nothing or another row is being updated.
You either need to employ some method of working out the row id to spinner position (e.g a second array that has the respective id for the same index of the first array), or to, what I'd do is, take advantage of the flexibility of a CursorAdpater, such as SimpleCursorAdapter and then use spinner.getSelectedItemId() instead of spinner.getSelectedItemPosition().
To use A CursorAdapter, you will need a row called _id (e.g. change private static final String KEY_ID = "id"; to public static final String KEY_ID = "_id";)
Note! I'd also suggest changing, as I have above, your private statics to public statics).
Also to use a CursorAdapter, you will need a Cursor. The following method in SpinnerDatabase.java would suffice.
public Cursor getAll() {
db = this.getWritableDatabase();
return db.query(TABLE_LABELS,null,null,null,null,null,null);
}
The following could be used to setup the adpater:-
csr = dbhlpr.getAll();
sca = new SimpleCursorAdapter(this,
android.R.layout.simple_list_item_1,
csr,
new String[]{SpinnerDatabase.KEY_NAME},
new int[]{android.R.id.text1},0);
spinner.setAdapter(sca);
Note! the use of SpinnerDatabase.KEY_NAME, this is an example of why I suggest 'public static' as opposed to private static.
There are sublte differences for the SimpleCursorAdpater;
- 3rd paramter is the Cursor,
- 4th is a String array of the column names in the cursor to be dis0played(should match 5th parameter),
- 5th is the id's of the views into which the data is placed (for simple_list_item_1 use 1 column name along with android.R.id.text1 as above).
and when it comes to the update use spinner.getSelectedItemId() for the row id.
Working Example (assumes rows have data)
SpinnerDatabase.java
public class SpinnerDatabase extends SQLiteOpenHelper {
private SQLiteDatabase db;
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "spinnerDB";
private static final String TABLE_LABELS = "labels";
private static final String KEY_ID = "_id";
public static final String KEY_NAME = "name";
public SpinnerDatabase(Context context) {
super(context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String CREATE_CATEGORIES_TABLES = "CREATE TABLE " +
TABLE_LABELS + "(" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"+
KEY_NAME + " TEXT)";
db.execSQL(CREATE_CATEGORIES_TABLES);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);
onCreate(db);
}
public void insertLabel(String label){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME,label);
db.insert(TABLE_LABELS,null,values);
}
//Defunct
public List<String> getAllLabels(){
List<String> labels = new ArrayList<String>();
String selectQuery = "SELECT * FROM "+ TABLE_LABELS;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery,null);
if (cursor.moveToFirst()){
do{
labels.add(cursor.getString(1));
}while (cursor.moveToNext());
}
cursor.close();
return labels;
}
public void updateSpinner (long id, String label){
ContentValues values;
String where;
db = this.getWritableDatabase();
where = KEY_ID + " = " +id;
values = new ContentValues();
values.put(KEY_NAME,label);
db.update(TABLE_LABELS,values,where,null);
db.close();
}
public Cursor getAll() {
db = this.getWritableDatabase();
return db.query(TABLE_LABELS,null,null,null,null,null,null);
}
}
Activity SO46330096Activity.java
public class SO46330096Activity extends AppCompatActivity {
SpinnerDatabase dbhlpr;
Spinner spinner;
Button editbutton;
EditText spinneritem;
SimpleCursorAdapter sca;
Cursor csr;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_so46330096);
spinner = (Spinner) findViewById(R.id.spinner);
editbutton = (Button) findViewById(R.id.editbutton);
spinneritem = (EditText) findViewById(R.id.spinnerinput);
dbhlpr = new SpinnerDatabase(this);
csr = dbhlpr.getAll();
sca = new SimpleCursorAdapter(this,
android.R.layout.simple_list_item_1,
csr,
new String[]{SpinnerDatabase.KEY_NAME},
new int[]{android.R.id.text1},0);
spinner.setAdapter(sca);
editbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (spinneritem.getText().toString().length() > 0) {
dbhlpr.updateSpinner(spinner.getSelectedItemId(),spinneritem.getText().toString());
sca.swapCursor(csr = dbhlpr.getAll());
}
}
});
}
}
The Layout activity_so46330096.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SO463300096 Activity"/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="SPINNER ENTRY"
/>
<EditText
android:id="@+id/spinnerinput"
android:layout_width="0dp"
android:layout_weight="3"
android:layout_height="match_parent" />
<Button
android:id="@+id/editbutton"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="match_parent"
android:text="EDIT"/>
</LinearLayout>
<Spinner
android:id="@+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</Spinner>
</LinearLayout>
Example usage:-
Spinner selected (note update data has already been entered):-
Peanut Butter selected and Updated data entered :-
After Clicking Edit button :-
Setting the EditText to the currently selected Spinner Item
The following can be used to set the EditText to the value of the currently selected spinner item:-
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
spinneritem.setText(csr.getString(csr.getColumnIndex(SpinnerDatabase.KEY_NAME)));
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
The could be added after setting the Adapter in the Activity.
In the aboveSO46330096Activity.java it could follow the line :-
spinner.setAdapter(sca);
这篇关于如何使用EditText中的用户输入更新微调器的字段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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