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<br>TextView
tv_num;// 用来显示剩余字数<br>int num = 10;//限制的最大字数 <br>
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et_content
= (EditText) findViewById(R.id.et_content);<br>tv_num = (TextView) findViewById(R.id.tv_num); <br>tv_num.setText( "10" );<br>
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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 } } });