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通过TextWatcher去观察输入框中输入的内容以及输入字符个数
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布局中EditText在android布局中经常用到,对EditText中输入的内容也经常需要进行限制,我们可以通过TextWatcher去观察输入框中输入的内容,作个笔记。
主布局:

  <?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"   android:orientation="vertical"   android:layout_width="fill_parent"   android:layout_height="fill_parent"  >  <TextView android:id="@+id/tv"   android:layout_width="fill_parent"   android:layout_height="wrap_content"   android:textColor="@android:color/white"   android:ellipsize="marquee"   android:focusable="true"   android:marqueeRepeatLimit="marquee_forever"   android:focusableInTouchMode="true"   android:scrollHorizontally="true"   android:text="Please input the text:"  />  <EditText android:id="@+id/ET"   android:layout_width="match_parent"   android:layout_height="wrap_content"   android:inputType="number"/>  </LinearLayout>

java代码:

package com.android.text; 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.TextView; import android.widget.Toast; public class TextWatcherDemo extends Activity { private TextView mTextView; private EditText mEditText; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super .onCreate(savedInstanceState); setContentView(R.layout.main); mTextView = (TextView)findViewById(R.id.tv); mEditText = (EditText)findViewById(R.id.ET); mEditText.addTextChangedListener(mTextWatcher); } TextWatcher mTextWatcher = new TextWatcher() { private CharSequence temp; private int editStart ; private int editEnd ; @Override public void beforeTextChanged(CharSequence s, int arg1, int arg2, int arg3) { temp = s; } @Override public void onTextChanged(CharSequence s, int arg1, int arg2, int arg3) { mTextView.setText(s); } @Override public void afterTextChanged(Editable s) { editStart = mEditText.getSelectionStart(); editEnd = mEditText.getSelectionEnd(); if (temp.length() > 10 ) { Toast.makeText(TextWatcherDemo. this , "你输入的字数已经超过了限制!" , Toast.LENGTH_SHORT) .show(); s.delete(editStart-1 , editEnd); int tempSelection = editStart; mEditText.setText(s); mEditText.setSelection(tempSelection); } } };}

 


原文链接:http://www.cnblogs.com/vus520/archive/2012/06/25/2561611.html
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长平狐
发帖于5年前 0回/111阅
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