布局文件

复制代码 代码如下:

<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=".MainActivity" >

<TextView

android:id="@+id/showWord"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignLeft="@+id/GreenBtn"

android:layout_alignParentTop="true"

android:layout_alignRight="@+id/BlueBtn"

android:layout_marginTop="17dp"

android:text="@string/ShowWordText"

android:text />

<Button

android:id="@+id/GreenBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_below="@+id/showWord"

android:layout_marginLeft="22dp"

android:layout_marginTop="28dp"

android:gravity="left|center_vertical|center_horizontal"

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

<Button

android:id="@+id/BlueBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBaseline="@+id/YellowBtn"

android:layout_alignBottom="@+id/YellowBtn"

android:layout_toRightOf="@+id/YellowBtn"

android:gravity="left|center_vertical|center_horizontal"

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

<Button

android:id="@+id/YellowBtn"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBaseline="@+id/GreenBtn"

android:layout_alignBottom="@+id/GreenBtn"

android:layout_toRightOf="@+id/GreenBtn"

android:gravity="left|center_vertical|center_horizontal"

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

</RelativeLayout>

复制代码 代码如下:

package com.example.demo1;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.TextView;

import android.app.Activity;

import android.graphics.Color;

public class MainActivity extends Activity implements OnClickListener{

TextView tv_show=null;

Button greenBtn=null;

Button blueBtn=null;

Button yellowBtn=null;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

tv_show=(TextView)findViewById(R.id.showWord);

greenBtn=(Button)findViewById(R.id.GreenBtn);

blueBtn=(Button)findViewById(R.id.BlueBtn);

yellowBtn=(Button)findViewById(R.id.YellowBtn);

greenBtn.setOnClickListener(this);

blueBtn.setOnClickListener(this);

yellowBtn.setOnClickListener(this);

}

@Override

public void onClick(View v) {

switch (v.getId()) {

case R.id.GreenBtn:

tv_show.setTextColor(Color.GREEN);

break;

case R.id.BlueBtn:

tv_show.setTextColor(Color.BLUE);

break;

case R.id.YellowBtn:

tv_show.setTextColor(Color.YELLOW);

break;

default:

break;

}

}

}