新手关于setText方法无效问题

cp111111 2016-05-23 10:28:19

最近在学习android开发，工具使用eclipse 4.12
简单的Textview控件使用setText方法，但发现无效，请各位大大指点一二
MainActivity文件

package com.example.test;



import android.app.Activity;

import android.os.Bundle;

import android.preference.EditTextPreference;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.LinearLayout;

import android.widget.TextView;



public class MainActivity extends Activity {



	private EditText edittext;

	private Button bt_button1;

	private Button bt_button2;

	private TextView txt_content;

	

		

	

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		bt_button1 = (Button)findViewById(R.id.bt_button1);

		edittext = (EditText)findViewById(R.id.edittext);

		txt_content = (TextView)findViewById(R.id.txt_content);

		//txt_content = (TextView)findViewById(R.id.);

		bt_button1.setOnClickListener(new OnClickListener() {

			

			@Override

			public void onClick(View v) {

				

				String a = edittext.getText().toString();

				

				txt_content.setText(a);

                               

				//txt_content.setText(edittext.getText().toString());

				// TODO 自动生成的方法存根

				

			}

		});

	}

layout文件：activity_main.xml

<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"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context="com.example.test.MainActivity" >



<LinearLayout 

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical">

    

    

        <TextView 

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/test"/>

    

    <EditText

        android:id="@+id/edittext" 

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"/>

    

    <LinearLayout 

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="horizontal"   >

        

        <Button 

        android:id="@+id/bt_button1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/button1"/>

        

            <Button 

        android:id="@+id/bt_button2"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/button2"/>

        

        

    </LinearLayout>

    

    

    <LinearLayout 

     android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical">

            

        <TextView 

            android:id="@+id/txt_content"

            android:layout_width="match_parent"

            android:layout_height="80dip"

            />

        

        

        

    </LinearLayout>

    

    

    

    </LinearLayout>

    



    

    



</RelativeLayout>

strings文件

<?xml version="1.0" encoding="utf-8"?>

<resources>



    <string name="app_name">Test</string>

    <string name="hello_world">Hello world!</string>

    <string name="action_settings">Settings</string>

    <string name="test">这是我的java手机程序测试</string>

    <string name="button1">确定</string>

    <string name="button2">取消</string>



</resources>

运行如下，只是把edittext控件值传给textview控件，但现在无效