android学习笔记002-拨打电话(优化)

package com.example.dailcall;

import android.support.v7.app.ActionBarActivity;
import android.text.TextUtils;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;//创建一个onClickListener接口的时候要导入这个包名
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends ActionBarActivity {

// 定义组建
private EditText et;
private Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et=(EditText) findViewById(R.id.et_number); //通过findViewById来查找组建名，绑定到定义的组建变量。
btn=(Button) findViewById(R.id.btn_dail);
btn.setOnClickListener(new MyClickListener());

}

private class MyClickListener implements OnClickListener{

@Override
public void onClick(View v) {
// TODO Auto-generated method stub

callNumber();

}

}

@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;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
//把callNumber（）这个动作写成一个私有的方法
private void callNumber() {
Intent intent=new Intent();

String number=et.getText().toString().trim();

if (TextUtils.isEmpty(number)) {
Toast.makeText(MainActivity.this, "电话号码不能为空！", 0).show();
return;
}

intent.setAction(Intent.ACTION_CALL);
intent.setData(Uri.parse("tel:"+number));

startActivity(intent);
}
}

<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.dailcall.MainActivity" >

<EditText
android:id="@+id/et_number"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:inputType="phone" >
<requestFocus />
</EditText>

<Button
android:id="@+id/btn_dail"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/et_number"
android:text="@string/dail" />

</RelativeLayout>