Android editText 输入字数限制

方法一：

// 输入框限制输入字数
        editText.addTextChangedListener(new TextWatcher() {
            private CharSequence temp;
            private boolean isEdit = true;
            private int selectionStart ;
            private int selectionEnd ;
            @Override
            public void beforeTextChanged(CharSequence s, int arg1, int arg2,
                    int arg3) {
                temp = s;
            }

            @Override
            public void onTextChanged(CharSequence s, int arg1, int arg2,
                    int arg3) {
            }

            @Override
            public void afterTextChanged(Editable s) {
                 selectionStart = editText.getSelectionStart();
                selectionEnd = editText.getSelectionEnd();
                Log.i("gongbiao1",""+selectionStart);
                if (temp.length() > Constant.TEXT_MAX) {
                    Toast.makeText(KaguHomeActivity.this,
                            R.string.edit_content_limit, Toast.LENGTH_SHORT)
                            .show();
                    s.delete(selectionStart-1, selectionEnd);
                    int tempSelection = selectionStart;
                    editText.setText(s);
                    editText.setSelection(tempSelection);
                }
            }


        });

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

// 输入框限制输入字数
       InputFilter[] filters = new InputFilter[1];
       filters[0] = new InputFilter.LengthFilter(Constant.TEXT_MAX) {
           @Override
           public CharSequence filter(CharSequence source, int start, int end,
                   Spanned dest, int dstart, int dend) {
               if (source.length() > 0 && dest.length() == Constant.TEXT_MAX) {
                   if ((System.currentTimeMillis() - toastTime) > interval) {
                       toastTime = System.currentTimeMillis();
                       Toast
                               .makeText(KaguHomeActivity.this,
                                       R.string.edit_content_limit,
                                       Toast.LENGTH_SHORT).show();
                   }
               }
               if (dest.toString().equals(
                       getResources().getString(R.string.input_default_txt))) {
                   Bundle data = new Bundle();
                   data.putCharSequence("source", source);
                   Message message = textHandler.obtainMessage();
                   message.setData(data);
                   message.sendToTarget();
               }

               return super.filter(source, start, end, dest, dstart, dend);
           }
       };
       editText.setFilters(filters);
rivate Handler textHandler = new Handler() {
       @Override
       public void handleMessage(Message msg) {

           Bundle data = msg.getData();
           CharSequence source = data.getCharSequence("source");
           editText.setTextColor(Color.BLACK);
           editText.setText(source);
           editText.setSelection(source.length());
       }
   };