Android中8个常用的操作

1.Android EditText的输入监听，输入字符的动态获取

有时候我们可能会用到时时的监听EditText输入字符的时时监听，监听字符的个数，做一些正则表达式的处理等。如下方法可以实现：

我做的是时时的把EditeText输入的数据同步到TextView上

布局文件：

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent" >

     <TextView
         android:id="@+id/textview"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerHorizontal="true"
         android:layout_centerVertical="true"
         android:padding="@dimen/padding_medium"
         tools:context=".Test02Activity" />

     <EditText
         android:id="@+id/editText1"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:layout_alignLeft="@+id/textview"
         android:layout_below="@+id/textview"
         android:layout_marginTop="31dp"
         >

         <requestFocus />
     </EditText>

 </RelativeLayout>

java代码：

 package com.example.testdemo;

 import android.os.Bundle;
 import android.app.Activity;
 import android.util.Log;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.widget.EditText;
 import android.widget.TextView;
 import android.support.v4.app.NavUtils;
 import android.text.Editable;
 import android.text.TextWatcher;

 public class Test02Activity extends Activity {
     private static final String TAG= "Test";
     private EditText mEditText;
     private TextView mTextView;
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_test02);
         mEditText = (EditText) findViewById(R.id.editText1);
         mTextView = (TextView) findViewById(R.id.textview);

         mEditText.addTextChangedListener(new TextWatcher(){

             @Override
             public void afterTextChanged(Editable s) {
                 Log.d(TAG, "afterTextChanged");
             }

             @Override
             public void beforeTextChanged(CharSequence s, int start, int count,
                     int after) {
                 Log.d(TAG, "beforeTextChanged:" + s + "-" + start + "-" + count + "-" + after);

             }

             @Override
             public void onTextChanged(CharSequence s, int start, int before,
                     int count) {
                 Log.d(TAG, "onTextChanged:" + s + "-" + "-" + start + "-" + before + "-" + count);
                 mTextView.setText(s);
             }

         });
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.activity_test02, menu);
         return true;
     }


 }
 public boolean uploadPostMethod(String path, Map<String, String> params) throws IOException{
         StringBuilder sb = new StringBuilder();
         for(Map.Entry<String, String> entry : params.entrySet()){
             //sb.append(entry.getKey()).append('=').append(entry.getValue()).append('&');
             sb.append(entry.getKey()).append('=').append(URLEncoder.encode(entry.getValue(), "UTF-8")).append('&');
         }
         sb.deleteCharAt(sb.length() - 1);
         byte[] entitydata = sb.toString().getBytes();
         URL url = new URL(path);
         HttpURLConnection conn = (HttpURLConnection)url.openConnection();
         conn.setConnectTimeout(5 * 1000);
         conn.setRequestMethod("POST");
         conn.setDoOutput(true);
         conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
         conn.setRequestProperty("Content-Length", String.valueOf(entitydata.length));
         OutputStream os = conn.getOutputStream();
         os.write(entitydata);
         os.flush();
         os.close();
         if(conn.getResponseCode() == 200){
             return true;
         }
         return false;
     }