android 格式化输入控制

Article from : http://horribile.blogspot.com/2011/11/formatting-edittext-input-with-regular.html

It will be the short article. Now we will format text in EditText with regular expressions.

The simple class will extend Input Filter:

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1. public class PartialRegexInputFilter implements InputFilter {  
2.    
3.     private Pattern mPattern;  
4.    
5.     public PartialRegexInputFilter(String pattern){  
6.       mPattern = Pattern.compile(pattern);  
7.     }   
8.   
9.     @Override  
10.     public CharSequence filter(CharSequence source,  
11.             int sourceStart, int sourceEnd,  
12.             Spanned destination, int destinationStart,  
13.             int destinationEnd)   
14.     {    
15.         String textToCheck = destination.subSequence(0, destinationStart).  
16.             toString() + source.subSequence(sourceStart, sourceEnd) +  
17.             destination.subSequence(  
18.             destinationEnd, destination.length()).toString();  
19.     
20.         Matcher matcher = mPattern.matcher(textToCheck);  
21.     
22.         // Entered text does not match the pattern  
23.         if(!matcher.matches()){  
24.      
25.             // It does not match partially too  
26.              if(!matcher.hitEnd()){  
27.                  return "";  
28.              }  
29.      
30.         }  
31.     
32.         return null;  
33.     }  
34.   
35. }  

The trick is that if the input text does not match the pattern it can match it partially.
If so we will allow the text pasting.

And finally formatting a phone number:

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1. final String regex = "\\(\\d{3}\\)\\d{3}\\-\\d{2}\\-\\d{2}";  
2.           
3. txt.setFilters(  
4.     new InputFilter[] {  
5.         new PartialRegexInputFilter(regex)  
6.     }  
7. );  
8.           
9. txt.addTextChangedListener(  
10.     new TextWatcher(){  
11.   
12.             @Override  
13.             public void afterTextChanged(Editable s) {  
14.                 String value  = s.toString();  
15.                 if(value.matches(regex))  
16.                     txt.setTextColor(Color.BLACK);  
17.                 else  
18.                     txt.setTextColor(Color.RED);  
19.             }  
20.   
21.             @Override  
22.             public void beforeTextChanged(CharSequence s, int start,  
23.                 int count, int after) {}  
24.   
25.             @Override  
26.             public void onTextChanged(CharSequence s, int start,  
27.                int before, int count) {}  
28.              
29.          }  
30. );  
31.           

We have: