android - 按住退格键不会一一清除文本

Question

我有一个 EditText 实现 TextWatcher，但退格键有问题。按住退格键时前5个字符会被一一清除，但转换为图像的后5个字符在按住退格键时无法一一清除。

看图:

1. MainActivity.java

   public class MainActivity extends AppCompatActivity {
   Spannable.Factory spannableFactory;
   
   protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);
   spannableFactory = Spannable.Factory
           .getInstance();
   
   final EditText editText = (EditText) findViewById(R.id.editText);
   editText.addTextChangedListener(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) {
           editText.removeTextChangedListener(this);
           if (s.length() >= 5) {
               editText.setText(getTextToIcon(getApplicationContext(), s));
           }
           if(count!=0){                               // != key delete
               if (s.length() - 1 > start) {
                   editText.setSelection(start + 1);
               } else {
                   editText.setSelection(s.length());
               }
           }else{                                      // = key delete
               editText.setSelection(start);
           }
   
           editText.addTextChangedListener(this);
       }
   
       @Override
       public void afterTextChanged(Editable s) {}
   });
   }
   
   
   public Spannable getTextToIcon(Context context, CharSequence text) {
   StringBuilder stringBuilder = new StringBuilder(text);
   Spannable spannable = spannableFactory.newSpannable(stringBuilder);
   int index = text.length() - 1;
   for(int i = 5; i<=index; i++){
       spannable.setSpan(new ImageSpan(context, android.R.drawable.star_on),
               i, i + 1,
               Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
   }
   return spannable;
   }
   }
   

2. activity_main.xml

   <?xml version="1.0" encoding="utf-8"?>
   <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent">
   
   <EditText
       android:id="@+id/editText"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:maxLength="10"
       android:inputType="number" />
   </LinearLayout>
   

Answer 1

兄弟，有bug的代码如下:

if (s.length() >= 5) {
    editText.setText(getTextToIcon(getApplicationContext(), s));
}

你应该把它改成这样:

if (count != 0 && s.length() >= 5) {
    // just set the text to the icon in input state instead of pressing delete key in soft method
    editText.setText(getTextToIcon(getApplicationContext(), s));
}

希望对您有所帮助。