4.1EditText 与TextView共舞--setonKeyListener事件

目标:

用户在文本框(EditText)里输入的文字同步显示到文字标签(TextView)里.

方法:

给EditText添加一个监听器(setOnKeyListener),在复写OnKye方法中实现功能.

代码: 

package edu.cquptzx.SetOnKeyListener;

 

import android.app.Activity;

import android.os.Bundle;

import android.view.KeyEvent;

import android.view.View;

import android.widget.EditText;

import android.widget.TextView;

 

publicclass SetOnKeyListenerActivity extends Activity {

    private TextView tv;

    private EditText et;

    /** Called when the activity is first created. */

    @Override

    publicvoid onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

       

        /*Find the view : tv and et .*/

        tv = (TextView) findViewById(R.id.textView);

        et = (EditText) findViewById(R.id.editText);

       

       et.setOnKeyListener(new EditText.OnKeyListener()

       {

       @Override

       publicboolean onKey(View v, int keyCode, KeyEvent event)

       {

           tv.setText(et.getText());

           returnfalse;

       }     

       });

    }

}

效果：