第四十二篇----拨打电话

界面：

MainActivity.java

package com.example.aimee.phone;


import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    public static final int REQUEST_CALL_PERMISSION = 10111;
    private Button bt_phone;
    private EditText et_phone;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        bt_phone = (Button) findViewById(R.id.button);
        et_phone = (EditText) findViewById(R.id.editview);

        bt_phone.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (checkReadPermission(Manifest.permission.CALL_PHONE, REQUEST_CALL_PERMISSION)) {
                    Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + et_phone.getText()));
                    startActivity(intent);
                }

            }
        });
    }

    public boolean checkReadPermission(String string_permission,int request_code) {
        boolean flag = false;
        if (ContextCompat.checkSelfPermission(MainActivity.this, string_permission) == PackageManager.PERMISSION_GRANTED) {//已有权限
            flag = true;
        } else {//申请权限
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{string_permission}, request_code);
        }
        return flag;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CALL_PERMISSION: //拨打电话
                if (permissions.length != 0 && grantResults[0] != PackageManager.PERMISSION_GRANTED) {//失败
                    Toast.makeText(MainActivity.this, "请允许拨号权限后再试", Toast.LENGTH_SHORT).show();
                } else {//成功
//                    call("tel:"+"10086");
                }
                break;
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/phonetext" />

    <EditText
        android:id="@+id/editview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:hint="@string/phonenumber"
        app:layout_constraintTop_toBottomOf="@+id/textview"/>

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/callphone"
        app:layout_constraintTop_toBottomOf="@+id/editview"/>

</android.support.constraint.ConstraintLayout>

最后，不要忘记在清单文件中添加权限

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

小提示

1.可以自己设置快捷输入方式.

Settings-->Editor-->Live Templates，查看常用语句的快捷输入法，比如output里面的sout，当你在代码中输入sout按回车，那么就会自动补全System.out.println();如果点击右边的加号可以自己定义输入快捷方式。

2.常用快捷键Alt+Enter

一般代码飘红，可以尝试使用Alt+Enter

另外，输入（Button）你打印find会出现findViewById();然后填入R.id.button后将鼠标定位到括号后面，Alt+Enter，会自动补全成Button button = (Button) findViewById(R.id.button);此时你可以更换button名字，或者直接按enter就行了。如果你想要Button button在onCreate外面定义，可以按Ctrl+alt+f，它就会自动生成变量。