android程式設計實例入門 -Sample改寫分享 (2014/09/17)

 

此範例為程式碼(04\Sample3)的改寫，利用一個LinearLayout、一個TextView和一個Button實作GUI界面，並且利用Button的setEnabled函數控制Button是否可以反應事件範例，程式碼如下所示： 

 

package com.jashsample;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.Color;
import android.graphics.Typeface;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
/*
 * 透過Button的setEnabled函數控制Button是否可以反應事件
 */
public class MainActivity extends Activity {
TextView tv;
Button bt;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LinearLayout ll = new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
setContentView(ll);
tv = new TextView(this);
tv.setText("歡迎光臨。");
bt = new Button(this);
bt.setText("購買");
ll.addView(tv);
ll.addView(bt);
bt.setOnClickListener(new SampleClickListener());
}
public boolean onKeyDown(int keycode, KeyEvent e)//直接在Activity上實作KeyDown事件
{
String str;
switch(keycode)
{
case KeyEvent.KEYCODE_DPAD_UP:
str = "上";
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
str = "下";
break;
case KeyEvent.KEYCODE_DPAD_LEFT:
str = "左";
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
str = "右";
break;
case KeyEvent.KEYCODE_DPAD_CENTER:
str = "中央";
break;
default:
str = "其他按鍵";
}
tv.setText("是按下" + str + "。");
return true;
}
public boolean onTouchEvent(MotionEvent e)//直接在Activity上實作Touch事件
{
if(e.getAction() == MotionEvent.ACTION_DOWN)//設定在畫面任何地方Touch都改變tv文字
{
tv.setText("您好再見");
}
else if(e.getAction() == MotionEvent.ACTION_UP)
{
tv.setText("再見您好");
}
return true;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
class SampleTouchListener implements OnTouchListener
{
public boolean onTouch(View v, MotionEvent e)
{
if(e.getAction() == MotionEvent.ACTION_DOWN)
{
tv.setText("您好");
}
else if(e.getAction() == MotionEvent.ACTION_UP)
{
tv.setText("再見");
}
return true;
}
}
class SampleClickListener implements OnClickListener//按鈕事件反事類別
{
public void onClick(View v)
{
tv.setText("謝謝惠顧。");
bt.setEnabled(false);
}
}
}