【android】调用系统拨号器进行拨号

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
private Button call;
private TextView tv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv=(TextView)findViewById(R.id.et1);
call=(Button)findViewById(R.id.call);
call.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String phone=tv.getText().toString();       //得到电话号码
Intent intent=new Intent();
intent.setAction(Intent.ACTION_CALL);
intent.setData(Uri.parse("tel:"+phone));
MainActivity.this.startActivity(intent);
}
});
}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
android:layout_gravity="center"
tools:context="com.example.tony_chen.call_phone.MainActivity">

<TextView
android:layout_width="386dp"
android:layout_height="37dp"
android:text="迷你拨号器："
android:textColor="@color/colorAccent"
android:textSize="30sp"
android:textStyle="italic"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="60dp" />
<EditText
android:id="@+id/et1"
android:layout_width="366dp"
android:layout_height="42dp"
android:hint="请输入手机号"
android:inputType="phone"
tools:layout_editor_absoluteX="0dp"
tools:layout_editor_absoluteY="111dp" />
<Button
android:id="@+id/call"
android:layout_width="142dp"
android:layout_height="50dp"
android:text="拨出"
tools:layout_editor_absoluteX="241dp"
tools:layout_editor_absoluteY="158dp" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.tony_chen.call_phone">
//添加权限
<uses-permission android:name="android.permission.CALL_PHONE"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>