Android中EditText的輸入字數限制

在開發應用的時候，經常會限制使用者輸入的字數，比如發表評論或者其它什麼的，下面來個簡單的demo

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");

下面為EditText文字框添加監聽

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);//設定游標在最後
                }
            }
        });

這樣就可以實現了