代碼設置EditText 長度

很多時候我們都要設置文本最大長度,可以通過XML來設置,也可以通過代碼來設置,
我這裏介紹兩種方法:
一:
網上大多數是使用以下的方法來計算.這樣的方法很長,當然也有它的優勢,這樣比較靈活,但我是一個懶惰的程序員,我介紹另外一種方法

EditText et_content;//定義一個文本輸入框
TextView tv_num;// 用來顯示剩餘字數
int num = 10;//限制的最大字數
et_content = (EditText) findViewById(R.id.et_content);
tv_num = (TextView) findViewById(R.id.tv_num);
tv_num.setText("10");
下面爲EditText文本框添加監聽


et_content.addTextChangedListener(new TextWatcher() {
            private CharSequence temp;
            private int selectionStart;
            private int selectionEnd;

            @Override
            public void onTextChanged(CharSequence s, int start, int before,
                    int count) {
                temp = s;
                System.out.println("s="+s);
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {
            }

            @Override
             public void afterTextChanged(Editable s) {
                int number = num - s.length();
                tv_num.setText("" + number);
                selectionStart = et_content.getSelectionStart();
                selectionEnd = et_content.getSelectionEnd();
                //System.out.println("start="+selectionStart+",end="+selectionEnd);
                if (temp.length() > num) {
                    s.delete(selectionStart - 1, selectionEnd);
                    int tempSelection = selectionStart;
                    et_content.setText(s);
                    et_content.setSelection(tempSelection);//設置光標在最後
                }
            }
        });
二:
    通過源碼可以看到,
if (maxlength >= 0) {
            setFilters(new InputFilter[] { new InputFilter.LengthFilter(maxlength) });
        } else {
            setFilters(NO_FILTERS);
        }
這樣,簡單來說,我們就可以通過EditText對象來設置
mEditText.setFilters(new InputFilter[]{ new InputFilter.LengthFilter(100) });
這樣既可.