在开发应用的时候,经常会限制用户输入的字数,比如发表评论或者其它什么的,下面来个简单的demo
EditText et_content;//定义一个文本输入框
TextView tv_num;// 用来显示剩余字数
int num = 10;//限制的最大字数
et_content = (EditText) findViewById(R.id.et_content);
tv_num = (TextView) findViewById(R.id.tv_num);
tv_num.setText("10");
下面为EditText文本框添加监听
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);//设置光标在最后
}
}
});
这样就可以实现了