如何使用 CursorAdapter 将 Filter 设置为 ListView?
How to set Filter to ListView with CursorAdapter?
我有一个ListView
。它的哪些项目来自自定义 CursorAdapter
。我为 CardView
的 ListView 项目创建了单独的布局。我在每张卡片上有六个 TextViews
它们是 Database
值。现在我必须根据在 EditText 中输入的文本放置一个 EditText
来过滤 ListView 项目。
我的代码是
ListView 的布局是
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#1d4563">
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView2"
android:layout_marginTop="40dp"
android:layout_centerHorizontal="true" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="number"
android:ems="10"
android:id="@+id/editText5"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:background="@drawable/bg_edit"
android:textColorHint="#d3d3d3"
android:hint="enter Serial Number to search" />
ListView 项目布局为
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android.support.v7.cardview="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android.support.v7.cardview:cardBackgroundColor="@color/primary_dark"
android:id="@+id/cardItems">
<android.support.v7.widget.CardView
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="fill_parent"
android:layout_height="150dp"
android:layout_margin="1dp"
card_view:cardCornerRadius="0dp"
card_view:contentPadding="2dp">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/card_style">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Username"
android:id="@+id/textView24"
android:textColor="#FFFFFF"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_marginTop="8dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Mobile No."
android:id="@+id/textView25"
android:textColor="#FFFFFF"
android:layout_centerVertical="true"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_alignRight="@+id/textView24"
android:layout_alignEnd="@+id/textView24" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Serial No."
android:id="@+id/textView26"
android:textColor="#FFFFFF"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_alignParentBottom="true"
android:layout_marginBottom="8dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView27"
android:textColor="#FFFFFF"
android:layout_marginTop="8dp"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView28"
android:textColor="#FFFFFF"
android:layout_centerVertical="true"
android:layout_alignLeft="@+id/textView27"
android:layout_alignStart="@+id/textView27" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView29"
android:layout_alignTop="@+id/textView26"
android:layout_alignLeft="@+id/textView28"
android:layout_alignStart="@+id/textView28"
android:layout_marginBottom="8dp"
android:textColor="#FFFFFF"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
我的DisplayAdapter
是
public class DisplayAdapter extends CursorAdapter{
@SuppressWarnings("deprecation")
public DisplayAdapter(Context context,Cursor c){
super(context,c);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View retView = inflater.inflate(R.layout.card_items, parent, false);
return retView;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView tvUserName=(TextView)view.findViewById(R.id.textView27);
tvUserName.setText(cursor.getString(2));
TextView tvMobile=(TextView)view.findViewById(R.id.textView28);
tvMobile.setText(cursor.getString(3));
TextView tvSerail=(TextView)view.findViewById(R.id.textView29);
tvSerail.setText(cursor.getString(5));
}
}
我的Activity是
public class TableBikeActivity extends ActionBarActivity {
private DisplayAdapter adapter;
ListView bikeList;
DatabaseHelper databaseHelper;
EditText filterText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_table_bike);
databaseHelper=new DatabaseHelper(this);
bikeList=(ListView)findViewById(R.id.listView2);
filterText=(EditText)findViewById(R.id.editText5);
filterText.addTextChangedListener(filterTextWatcher);
new Handler().post(new Runnable() {
@Override
public void run() {
adapter = new DisplayAdapter(TableBikeActivity.this, databaseHelper.getAllDataBike());
bikeList.setAdapter(adapter);
}
});
}
private TextWatcher filterTextWatcher=new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
adapter.getFilter().filter(s);
}
@Override
public void afterTextChanged(Editable s) {
}
};
@Override
protected void onDestroy(){
super.onDestroy();
filterText.removeTextChangedListener(filterTextWatcher);
}
}
我试过 TextChangedListener,但它不起作用。帮帮我。
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
adapter_members.getFilter().filter(s.toString());
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
setTextFilterEnabled()
方法不会自动执行过滤,因为它不知道您的 Cursor 中的文本应该根据什么进行过滤。
对于CursorAdapter
游标,你只需要使用setFilterQueryProvider
,到运行另一个查询你的游标,基于约束:
m_Adapter.setFilterQueryProvider(new FilterQueryProvider() {
public Cursor runQuery(CharSequence constraint) {
Log.d(LOG_TAG, "runQuery constraint:"+constraint);
//uri, projection, and sortOrder might be the same as previous
//but you might want a new selection, based on your filter content (constraint)
Cursor cur = managedQuery(uri, projection, selection, selectionArgs, sortOrder);
return cur; //now your adapter will have the new filtered content
}
});
添加约束(例如,通过使用 TextView)时,必须过滤适配器:
public void onTextChanged(CharSequence s, int start, int before, int count) {
Log.d(LOG_TAG, "Filter:"+s);
if (m_slvAdapter!=null) {
m_Adapter.getFilter().filter(s);
}
}
这是我的方法,因为我找不到任何对我有帮助的方法。我不知道是否有更好的解决方案,但至少它是可行的。
首先,您需要在具有列表视图的布局中有一个 EditText 元素,我们称之为 inputSearch。
在您的 activity 中声明一个来自 MatrixCursor 类型的全局变量,稍后将用于过滤结果 - 这个特殊的游标是一个游标,可以通过简单的函数处理元素像 addRow():
矩阵游标 lastValidSearchResult;
在你的代码中的某个地方,你初始化你的游标,你将用它来提供你的游标适配器,将游标的结果也保存在 lastValidSearchResult
:
Cursor myCursor = myDbObj.doMyQuery();
lastValidSearchResult = myCursor;
- 对于 EditText 元素,您可以像这样实现 addTextChangedListener 方法:
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
// yourCustomCursorAdapter is the adapter for which you implemented a custom class - so in your case of type display adapter
YourCurrentActivity.this.yourCustomCursorAdapter.getFilter().filter(cs.toString());
YourCurrentActivity.this.yourCustomCursorAdapter.notifyDataSetChanged();
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) { }
@Override
public void afterTextChanged(Editable arg0) {}
});
- 最后但并非最不重要的是执行过滤器的代码片段。为此,您需要为自定义适配器的函数 setFilterQueryProvider 实现代码(在本例中是来自 DisplayAdapter 的对象):
yourCustomCursorAdapter.setFilterQueryProvider(new FilterQueryProvider() {
// constraint is the variable which is passed from your text change listener
public Cursor runQuery(CharSequence constraint) {
// if the search string is empty, then return the original cursor with all results from the original query
if(constraint.equals(""))
{
return myCursor;
}
MatrixCursor filteredValues = new MatrixCursor(new String[]{/*Same columns as your original cursor myCursor*/);
while(myCursor.moveToNext()) {
String smth = myCursor.getString(myCursor.getColumnIndex(validColumnIndex);
String smth2 = ....
//Some condition to check previous data is not matched and only then add row
if (smth.toLowerCase().contains(constraint.toString().toLowerCase())) {
filteredValues.addRow(new String[]{smth, ...});
}
}
// do not forget next line since you manipulated your original cursor with moveToNext
yourCursor.moveToFirst();
// If your search value was not found at all return the last valid search result
if(filteredValues.getCount() == 0)
{
return lastValidSearchResult;
}
// else you can save the new correct search result and return the results
lastValidSearchResult = filteredValues;
return filteredValues; //now your adapter will have the new filtered content
}});
我有一个ListView
。它的哪些项目来自自定义 CursorAdapter
。我为 CardView
的 ListView 项目创建了单独的布局。我在每张卡片上有六个 TextViews
它们是 Database
值。现在我必须根据在 EditText 中输入的文本放置一个 EditText
来过滤 ListView 项目。
我的代码是
ListView 的布局是
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#1d4563">
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/listView2"
android:layout_marginTop="40dp"
android:layout_centerHorizontal="true" />
<EditText
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:inputType="number"
android:ems="10"
android:id="@+id/editText5"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"
android:background="@drawable/bg_edit"
android:textColorHint="#d3d3d3"
android:hint="enter Serial Number to search" />
ListView 项目布局为
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android.support.v7.cardview="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android.support.v7.cardview:cardBackgroundColor="@color/primary_dark"
android:id="@+id/cardItems">
<android.support.v7.widget.CardView
android:id="@+id/card_view"
android:layout_gravity="center"
android:layout_width="fill_parent"
android:layout_height="150dp"
android:layout_margin="1dp"
card_view:cardCornerRadius="0dp"
card_view:contentPadding="2dp">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@drawable/card_style">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Username"
android:id="@+id/textView24"
android:textColor="#FFFFFF"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_marginTop="8dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Mobile No."
android:id="@+id/textView25"
android:textColor="#FFFFFF"
android:layout_centerVertical="true"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_alignRight="@+id/textView24"
android:layout_alignEnd="@+id/textView24" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Serial No."
android:id="@+id/textView26"
android:textColor="#FFFFFF"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_alignParentBottom="true"
android:layout_marginBottom="8dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView27"
android:textColor="#FFFFFF"
android:layout_marginTop="8dp"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView28"
android:textColor="#FFFFFF"
android:layout_centerVertical="true"
android:layout_alignLeft="@+id/textView27"
android:layout_alignStart="@+id/textView27" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="New Text"
android:id="@+id/textView29"
android:layout_alignTop="@+id/textView26"
android:layout_alignLeft="@+id/textView28"
android:layout_alignStart="@+id/textView28"
android:layout_marginBottom="8dp"
android:textColor="#FFFFFF"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
我的DisplayAdapter
是
public class DisplayAdapter extends CursorAdapter{
@SuppressWarnings("deprecation")
public DisplayAdapter(Context context,Cursor c){
super(context,c);
}
@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View retView = inflater.inflate(R.layout.card_items, parent, false);
return retView;
}
@Override
public void bindView(View view, Context context, Cursor cursor) {
TextView tvUserName=(TextView)view.findViewById(R.id.textView27);
tvUserName.setText(cursor.getString(2));
TextView tvMobile=(TextView)view.findViewById(R.id.textView28);
tvMobile.setText(cursor.getString(3));
TextView tvSerail=(TextView)view.findViewById(R.id.textView29);
tvSerail.setText(cursor.getString(5));
}
}
我的Activity是
public class TableBikeActivity extends ActionBarActivity {
private DisplayAdapter adapter;
ListView bikeList;
DatabaseHelper databaseHelper;
EditText filterText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_table_bike);
databaseHelper=new DatabaseHelper(this);
bikeList=(ListView)findViewById(R.id.listView2);
filterText=(EditText)findViewById(R.id.editText5);
filterText.addTextChangedListener(filterTextWatcher);
new Handler().post(new Runnable() {
@Override
public void run() {
adapter = new DisplayAdapter(TableBikeActivity.this, databaseHelper.getAllDataBike());
bikeList.setAdapter(adapter);
}
});
}
private TextWatcher filterTextWatcher=new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
adapter.getFilter().filter(s);
}
@Override
public void afterTextChanged(Editable s) {
}
};
@Override
protected void onDestroy(){
super.onDestroy();
filterText.removeTextChangedListener(filterTextWatcher);
}
}
我试过 TextChangedListener,但它不起作用。帮帮我。
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence s, int start, int before,
int count) {
// TODO Auto-generated method stub
adapter_members.getFilter().filter(s.toString());
}
@Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
}
setTextFilterEnabled()
方法不会自动执行过滤,因为它不知道您的 Cursor 中的文本应该根据什么进行过滤。
对于CursorAdapter
游标,你只需要使用setFilterQueryProvider
,到运行另一个查询你的游标,基于约束:
m_Adapter.setFilterQueryProvider(new FilterQueryProvider() {
public Cursor runQuery(CharSequence constraint) {
Log.d(LOG_TAG, "runQuery constraint:"+constraint);
//uri, projection, and sortOrder might be the same as previous
//but you might want a new selection, based on your filter content (constraint)
Cursor cur = managedQuery(uri, projection, selection, selectionArgs, sortOrder);
return cur; //now your adapter will have the new filtered content
}
});
添加约束(例如,通过使用 TextView)时,必须过滤适配器:
public void onTextChanged(CharSequence s, int start, int before, int count) {
Log.d(LOG_TAG, "Filter:"+s);
if (m_slvAdapter!=null) {
m_Adapter.getFilter().filter(s);
}
}
这是我的方法,因为我找不到任何对我有帮助的方法。我不知道是否有更好的解决方案,但至少它是可行的。
首先,您需要在具有列表视图的布局中有一个 EditText 元素,我们称之为 inputSearch。
在您的 activity 中声明一个来自 MatrixCursor 类型的全局变量,稍后将用于过滤结果 - 这个特殊的游标是一个游标,可以通过简单的函数处理元素像 addRow():
矩阵游标 lastValidSearchResult;
在你的代码中的某个地方,你初始化你的游标,你将用它来提供你的游标适配器,将游标的结果也保存在
lastValidSearchResult
:
Cursor myCursor = myDbObj.doMyQuery();
lastValidSearchResult = myCursor;
- 对于 EditText 元素,您可以像这样实现 addTextChangedListener 方法:
inputSearch.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
// yourCustomCursorAdapter is the adapter for which you implemented a custom class - so in your case of type display adapter
YourCurrentActivity.this.yourCustomCursorAdapter.getFilter().filter(cs.toString());
YourCurrentActivity.this.yourCustomCursorAdapter.notifyDataSetChanged();
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) { }
@Override
public void afterTextChanged(Editable arg0) {}
});
- 最后但并非最不重要的是执行过滤器的代码片段。为此,您需要为自定义适配器的函数 setFilterQueryProvider 实现代码(在本例中是来自 DisplayAdapter 的对象):
yourCustomCursorAdapter.setFilterQueryProvider(new FilterQueryProvider() {
// constraint is the variable which is passed from your text change listener
public Cursor runQuery(CharSequence constraint) {
// if the search string is empty, then return the original cursor with all results from the original query
if(constraint.equals(""))
{
return myCursor;
}
MatrixCursor filteredValues = new MatrixCursor(new String[]{/*Same columns as your original cursor myCursor*/);
while(myCursor.moveToNext()) {
String smth = myCursor.getString(myCursor.getColumnIndex(validColumnIndex);
String smth2 = ....
//Some condition to check previous data is not matched and only then add row
if (smth.toLowerCase().contains(constraint.toString().toLowerCase())) {
filteredValues.addRow(new String[]{smth, ...});
}
}
// do not forget next line since you manipulated your original cursor with moveToNext
yourCursor.moveToFirst();
// If your search value was not found at all return the last valid search result
if(filteredValues.getCount() == 0)
{
return lastValidSearchResult;
}
// else you can save the new correct search result and return the results
lastValidSearchResult = filteredValues;
return filteredValues; //now your adapter will have the new filtered content
}});