Android editText 输入字数限制

DerekGuo_lzu

方法一：

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1. // 输入框限制输入字数  
2.         editText.addTextChangedListener(new TextWatcher() {  
3.             private CharSequence temp;  
4.             private boolean isEdit = true;  
5.             private int selectionStart ;  
6.             private int selectionEnd ;  
7.             @Override  
8.             public void beforeTextChanged(CharSequence s, int arg1, int arg2,  
9.                     int arg3) {  
10.                 temp = s;  
11.             }  
12.    
13.             @Override  
14.             public void onTextChanged(CharSequence s, int arg1, int arg2,  
15.                     int arg3) {  
16.             }  
17.    
18.             @Override  
19.             public void afterTextChanged(Editable s) {  
20.                  selectionStart = editText.getSelectionStart();  
21.                 selectionEnd = editText.getSelectionEnd();  
22.                 Log.i("gongbiao1",""+selectionStart);  
23.                 if (temp.length() > Constant.TEXT_MAX) {  
24.                     Toast.makeText(KaguHomeActivity.this,  
25.                             R.string.edit_content_limit, Toast.LENGTH_SHORT)  
26.                             .show();  
27.                     s.delete(selectionStart-1, selectionEnd);  
28.                     int tempSelection = selectionStart;  
29.                     editText.setText(s);  
30.                     editText.setSelection(tempSelection);  
31.                 }  
32.             }  
33.    
34.    
35.         });  

方法二：
利用EditText 可以设置filter的特性，自定义一个LengthFilter，当输入字数超过限制时 ，做出自定义的提示

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1. // 输入框限制输入字数  
2.        InputFilter[] filters = new InputFilter[1];  
3.        filters[0] = new InputFilter.LengthFilter(Constant.TEXT_MAX) {  
4.            @Override  
5.            public CharSequence filter(CharSequence source, int start, int end,  
6.                    Spanned dest, int dstart, int dend) {  
7.                if (source.length() > 0 && dest.length() == Constant.TEXT_MAX) {  
8.                    if ((System.currentTimeMillis() - toastTime) > interval) {  
9.                        toastTime = System.currentTimeMillis();  
10.                        Toast  
11.                                .makeText(KaguHomeActivity.this,  
12.                                        R.string.edit_content_limit,  
13.                                        Toast.LENGTH_SHORT).show();  
14.                    }  
15.                }  
16.                if (dest.toString().equals(  
17.                        getResources().getString(R.string.input_default_txt))) {  
18.                    Bundle data = new Bundle();  
19.                    data.putCharSequence("source", source);  
20.                    Message message = textHandler.obtainMessage();  
21.                    message.setData(data);  
22.                    message.sendToTarget();  
23.                }  
24.   
25.                return super.filter(source, start, end, dest, dstart, dend);  
26.            }  
27.        };  
28.        editText.setFilters(filters);  
29. rivate Handler textHandler = new Handler() {  
30.        @Override  
31.        public void handleMessage(Message msg) {  
32.   
33.            Bundle data = msg.getData();  
34.            CharSequence source = data.getCharSequence("source");  
35.            editText.setTextColor(Color.BLACK);  
36.            editText.setText(source);  
37.            editText.setSelection(source.length());  
38.        }  
39.    };