android editText输入文本框限制输入字数和字数提示

EditText content;//定义一个文本输入框

TextView hasnum;// 用来显示剩余字数

int num
= 140;//限制的最大字数　　

content =
(EditText) findViewById(R.id.et_content);

hasnumTV =
(TextView) findViewById(R.id.tv_num);

hasnumTV.setText(num+"");

//下面为EditText文本框添加监听

content.addTextChangedListener(new
TextWatcher()
{

private
CharSequence temp;

private
int selectionStart;

private
int selectionEnd;

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

}

public
void onTextChanged(CharSequence s,
int start,
int before,
int count)
{

temp = s;

}

public
void afterTextChanged(Editable s)
{

int number
= num - s.length();

hasnumTV.setText(""
+ number);

selectionStart = content.getSelectionStart();

selectionEnd = content.getSelectionEnd();

if (temp.length()
> num)
{

s.delete(selectionStart
- 1, selectionEnd);

int tempSelection
= selectionEnd;

content.setText(s);

content.setSelection(tempSelection);//设置光标在最后

}

}

});