android 中如何限制 EditText 最大输入字符数(2)

方法四：

基本思路同方法三，监听 EditText 当中输入字符串的长度，如果超长，给出提示。

package cie.textEdit;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.widget.EditText;
import android.widget.Toast;

public class TextEditActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

final EditText editText = (EditText)findViewById(R.id.entry);
editText.addTextChangedListener(new TextWatcher(){
private int selectionStart = 0;
private int selectionEnd = 0;
private CharSequence temp = null;

public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
selectionStart = editText.getSelectionStart();
selectionEnd = editText.getSelectionEnd();
Log.i(myConstant.Tag,"selectionStart" + selectionStart);
if(temp.length() > myConstant.TextMaxLen)
{
Toast.makeText(TextEditActivity.this, R.string.string_limit, Toast.LENGTH_SHORT).show();
arg0.delete(selectionStart-1, selectionEnd);
int tempSelection = selectionStart;
editText.setText(arg0);
editText.setSelection(tempSelection);
}
}

public void beforeTextChanged(CharSequence arg0, int arg1,
int arg2, int arg3) {
// TODO Auto-generated method stub
temp = arg0;
}

public void onTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub

}

});
}
}


当文本输入字符数10个，再输入字符时，就会出现