这里采用的是LinearLayout是线性布局控件，LinearLayout详细介绍

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="vertical"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
>

接着在activity_main.xml新建输入文本框,添加特殊的id属性android:id="@+id/et_number"，这里‘+’表示动态向R文件添加一个静态的内部类id，然后在R文件中动态的添加了一个et_number,以便后面进行操作

 <EditText
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:numeric="integer"
        android:lines = "1"
        android:hint="@string/hint"
        android:id="@+id/et_number"
        />
    

其中在<EditText/>文本框下添加限制只能输入一行并且全部为数字的字符

android:numeric="integer"
android:lines = "1"

接下来处理按钮点击事件
在MainActivity中添加this.findViewById(R.id.bt_dail);就能找到该按钮，它返回的其实是一个view，继承关系是button继承自TextView，TextView又继承自View
注册MainActivity的tag
public static final String tag = "MainActivity";
添加点击事件

Button button = (Button)this.findViewById(R.id.bt_dail);
button.setOnClickListener((OnClickListener) new MyButtonClickListener());


private class MyButtonClickListener implements OnClickListener
	{
		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			System.out.println("按钮被点击了");
			Log.i(tag, "button被点击了");
			Log.e(tag, "error");
			Log.d(tag, "debug");
			Log.v(tag,"verbios");
			Log.w(tag, "warm");
			
		}
	}

点击按钮会在Log日志中会输对应的日志

然后实现拨打电话的功能

private class MyButtonClickListener implements OnClickListener
{
		@Override
		public void onClick(View v) {
			// TODO Auto-generated method stub
			//拿到电话号码
			EditText mEditText = (EditText)MainActivity.this.findViewById(R.id.et_number);
			String number = mEditText.getText().toString();
			Log.i(tag, number);
			//拨打电话号码
			Intent intent = new Intent();//意图 代表一个要执行动作的意图
			//拨打动作 110
			intent.setAction(Intent.ACTION_CALL);//Intent.ACTION_DAL是拨号的操作
			//输入的话就拨打输入的，不属于的话就拨打作者的号码
			if(!"".equals(number))
			{
				intent.setData(Uri.parse("tel:"+number));
			}
			else
			{
				Log.i(tag, "我的号码");
				intent.setData(Uri.parse("tel:"+"13262983383"));
			}
			//激活意图
			startActivity(intent);
}

到目前为止代码是差不多了点击运行，会发现报错了

我们来查看权限错误的Log日志

04-09 11:31:19.945: E/AndroidRuntime(516): java.lang.SecurityException: Permission Denial: starting Intent { act=android.intent.action.CALL dat=tel:110 cmp=com.android.phone/.OutgoingCallBroadcaster } from ProcessRecord{45ec9830 516:com.example.phonecall/10038} (pid=516, uid=10038) requires android.permission.CALL_PHONE
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.os.Parcel.readException(Parcel.java:1247)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.os.Parcel.readException(Parcel.java:1235)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1298)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.app.Instrumentation.execStartActivity(Instrumentation.java:1373)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.app.Activity.startActivityForResult(Activity.java:2817)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.app.Activity.startActivity(Activity.java:2923)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at com.example.phonecall.MainActivity$MyButtonClickListener.onClick(MainActivity.java:45)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.view.View.performClick(View.java:2408)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.view.View$PerformClick.run(View.java:8816)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.os.Handler.handleCallback(Handler.java:587)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.os.Handler.dispatchMessage(Handler.java:92)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.os.Looper.loop(Looper.java:123)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at android.app.ActivityThread.main(ActivityThread.java:4627)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at java.lang.reflect.Method.invokeNative(Native Method)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at java.lang.reflect.Method.invoke(Method.java:521)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
04-09 11:31:19.945: E/AndroidRuntime(516): 	at dalvik.system.NativeStart.main(Native Method)

会发现这么一句

java.lang.SecurityException: Permission Denial

也就是没有权限，这里要配置允许调用系统打电话的功能

解决办法，添加权限
找到ANdroidManifest.xml清单文件，找到Permissions
Add->android.permission.CALL_PHONE_CALL

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