安卓：AutoCompleteTextView显示建议时没有输入文本
https://stackoverflow.com/questions/2126717
-
22-09-2019 - |
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我使用AutoCompleteTextView，当用户点击它，我想说明的建议，即使它没有文本 - 但setThreshold(0)作品完全一样setThreshold(1) - 因此，用户必须输入至少1个字符显示的建议
解决方案
这是记录的行为：
当
threshold小于或等于0，1的阈值是 应用
您可以手动表明通过showDropDown()下拉，所以也许你可以安排来显示它时，你想要的。或者，子类和AutoCompleteTextView倍率enoughToFilter()，返回的所有时间true。
其他提示
下面是我的类 InstantAutoComplete 。它的东西AutoCompleteTextView和Spinner之间。
import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.AutoCompleteTextView;
public class InstantAutoComplete extends AutoCompleteTextView {
public InstantAutoComplete(Context context) {
super(context);
}
public InstantAutoComplete(Context arg0, AttributeSet arg1) {
super(arg0, arg1);
}
public InstantAutoComplete(Context arg0, AttributeSet arg1, int arg2) {
super(arg0, arg1, arg2);
}
@Override
public boolean enoughToFilter() {
return true;
}
@Override
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
super.onFocusChanged(focused, direction, previouslyFocusedRect);
if (focused && getAdapter() != null) {
performFiltering(getText(), 0);
}
}
}
使用它在你的XML是这样的：
<your.namespace.InstantAutoComplete ... />
最简单的方法：
只需使用setOnTouchListener和showDropDown（）
AutoCompleteTextView text;
.....
.....
text.setOnTouchListener(new View.OnTouchListener(){
@Override
public boolean onTouch(View v, MotionEvent event){
text.showDropDown();
return false;
}
});
当只有一个InstantAutoComplete对象Destil的代码工作好了。 它没有有两个工作，虽然 - 不知道为什么。但是，当我把showDropDown()（就像CommonsWare决定）为onFocusChanged()这样的：
@Override
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
super.onFocusChanged(focused, direction, previouslyFocusedRect);
if (focused) {
performFiltering(getText(), 0);
showDropDown();
}
}
它解决了这个问题。
这仅仅是两个答案正确地进行组合，但我希望它可以节省的人一些时间。
在适配器不执行初始过滤。结果 如果不进行过滤，下拉列表是空的。结果 所以你可能必须得到过滤去开始。点击
要做到这一点，你可以调用filter()添加完条目后：点击
adapter.add("a1");
adapter.add("a2");
adapter.add("a3");
adapter.getFilter().filter(null);
Destil的回答几乎之上的作品，但是有一个微妙的错误。当用户第一次焦点放在上它的工作领域，但是如果他们离开，然后返回到外地它不会显示在下拉因为mPopupCanBeUpdated的价值仍然将是当它被隐藏假的。解决方法是在onFocusChanged方法更改为：
@Override
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
super.onFocusChanged(focused, direction, previouslyFocusedRect);
if (focused) {
if (getText().toString().length() == 0) {
// We want to trigger the drop down, replace the text.
setText("");
}
}
}
可以使用onFocusChangeListener;
TCKimlikNo.setOnFocusChangeListener(new OnFocusChangeListener() {
@Override
public void onFocusChange(View v, boolean hasFocus) {
if (hasFocus) {
TCKimlikNo.showDropDown();
}
}
});
若要CustomAutoCompleteTextView。 1.倍率setThreshold，enoughToFilter，onFocusChanged方法
public class CustomAutoCompleteTextView extends AutoCompleteTextView {
private int myThreshold;
public CustomAutoCompleteTextView (Context context) {
super(context);
}
public CustomAutoCompleteTextView (Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public CustomAutoCompleteTextView (Context context, AttributeSet attrs) {
super(context, attrs);
}
//set threshold 0.
public void setThreshold(int threshold) {
if (threshold < 0) {
threshold = 0;
}
myThreshold = threshold;
}
//if threshold is 0 than return true
public boolean enoughToFilter() {
return true;
}
//invoke on focus
protected void onFocusChanged(boolean focused, int direction,
Rect previouslyFocusedRect) {
//skip space and backspace
super.performFiltering("", 67);
// TODO Auto-generated method stub
super.onFocusChanged(focused, direction, previouslyFocusedRect);
}
protected void performFiltering(CharSequence text, int keyCode) {
// TODO Auto-generated method stub
super.performFiltering(text, keyCode);
}
public int getThreshold() {
return myThreshold;
}
}
只需拨打触摸此方法，或者点击autoCompleteTextView的事件或者你想要的。
autoCompleteTextView.showDropDown()
尝试
searchAutoComplete.setThreshold(0);
searchAutoComplete.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {//cut last probel
if (charSequence.length() > 1) {
if (charSequence.charAt(charSequence.length() - 1) == ' ') {
searchAutoComplete.setText(charSequence.subSequence(0, charSequence.length() - 1));
searchAutoComplete.setSelection(charSequence.length() - 1);
}
}
}
@Override
public void afterTextChanged(Editable editable) {
}
});
//when clicked in autocomplete text view
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.header_search_etv:
if (searchAutoComplete.getText().toString().length() == 0) {
searchAutoComplete.setText(" ");
}
break;
}
}):
这个工作对我来说，伪代码：
public class CustomAutoCompleteTextView extends AutoCompleteTextView {
public CustomAutoCompleteTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean enoughToFilter() {
return true;
}
@Override
protected void onFocusChanged(boolean focused, int direction, Rect previouslyFocusedRect) {
super.onFocusChanged(focused, direction, previouslyFocusedRect);
if (focused) {
performFiltering(getText(), 0);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
this.showDropDown();
return super.onTouchEvent(event);
}
}
就在Java中粘贴到您的onCreate方法
final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<>(
this, android.R.layout.simple_spinner_dropdown_item,
getResources().getStringArray(R.array.Loc_names));
textView1 =(AutoCompleteTextView) findViewById(R.id.acT1);
textView1.setAdapter(arrayAdapter);
textView1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(final View arg0) {
textView1.setMaxLines(5);
textView1.showDropDown();
}
});
和这对您的XML文件...
<AutoCompleteTextView
android:layout_width="200dp"
android:layout_height="30dp"
android:hint="@string/select_location"
android:id="@+id/acT1"
android:textAlignment="center"/>
和创建值下在string.xml数组...
<string-array name="Loc_names">
<item>Pakistan</item>
<item>Germany</item>
<item>Russia/NCR</item>
<item>China</item>
<item>India</item>
<item>Sweden</item>
<item>Australia</item>
</string-array>
，你是好去。
七年后，伙计们，这个问题保持不变。下面是一个函数，它的力量是愚蠢的弹出窗口，以显示自己在任何条件下的类。所有你需要做的是一个适配器设置为您AutoCompleteTextView，一些数据添加到它，和呼叫showDropdownNow()功能随时随地。
贷记@大卫Vávra。它是基于他的代码。
import android.content.Context
import android.util.AttributeSet
import android.widget.AutoCompleteTextView
class InstantAutoCompleteTextView : AutoCompleteTextView {
constructor(context: Context) : super(context)
constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs)
constructor(context: Context?, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
override fun enoughToFilter(): Boolean {
return true
}
fun showDropdownNow() {
if (adapter != null) {
// Remember a current text
val savedText = text
// Set empty text and perform filtering. As the result we restore all items inside of
// a filter's internal item collection.
setText(null, true)
// Set back the saved text and DO NOT perform filtering. As the result of these steps
// we have a text shown in UI, and what is more important we have items not filtered
setText(savedText, false)
// Move cursor to the end of a text
setSelection(text.length)
// Now we can show a dropdown with full list of options not filtered by displayed text
performFiltering(null, 0)
}
}
}
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