1  <uses-permission android:name="android.permission.CALL_PHONE" />

 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 2     xmlns:tools="http://schemas.android.com/tools" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent" 5     android:orientation="vertical" 6     tools:context=".MainActivity" > 7  8     <EditText 9         android:id="@+id/phoneNumber"10         android:layout_width="match_parent"11         android:layout_height="wrap_content"12         android:inputType="phone" />13 14     <Button15         android:id="@+id/btn_call"16         android:layout_width="match_parent"17         android:layout_height="wrap_content"18         android:text="打电话" />19 20 </LinearLayout>

 1 public class MainActivity extends Activity { 2  3     private EditText Number; 4  5     private Button btn; 6  7     @Override 8     protected void onCreate(Bundle savedInstanceState) { 9         super.onCreate(savedInstanceState);10         setContentView(R.layout.activity_main);11         Number = (EditText) findViewById(R.id.phoneNumber);12         btn = (Button) findViewById(R.id.btn_call);13         btn.setOnClickListener(new OnClickListener() {14 15             @Override16             public void onClick(View v) {17                 if (Number.getText().toString().trim().equals("")) {18                     Number.setError("电话号码不能为空");19                 } else {20 21                     Intent i = new Intent("android.intent.action.CALL", Uri22                             .parse("tel:" + Number.getText().toString().trim()));23                     startActivity(i);24                 }25 26             }27         });28 29     }30 }