隐式意图 implicit intent

在我们的APP中用于与其他APP交互

implicit intent 在声明时并不需要指定跳转的activity的名称，而是声明一个要执行的动作action，action中可以携带数据，也可以不携带，根据需求而定

比如说，当我们需要在我们的APP中呼叫某一个电话

package net.oschina.git.zhaikun.androiddeveloped.activitys;

import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import net.oschina.git.zhaikun.androiddeveloped.R;
import net.oschina.git.zhaikun.androiddeveloped.utils.MyTextUtils;

import java.util.List;

/**
 * Created by zhaikun68 on 2017/8/3.
 * <p>
 * 隐式意图
 */
public class ImplicitIntentActivity extends AppCompatActivity implements View.OnClickListener {

    private static final String CALL_10086 = "10086";//呼叫10086
    private static final String LOG_TAG = "ImplicitIntentActivity";
    private static final String MAP_URI = "geo:0,0?q=1600+Amphitheatre+Parkway,+Mountain+View,+California";

    private Button callPhoneBtn;//拨打电话
    private Button mapBtn;//地图

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_implicit_intent);
        initView();
    }

    /**
     * 组件初始化
     */
    private void initView() {
        callPhoneBtn = (Button) findViewById(R.id.btn_call_phone);
        mapBtn = (Button) findViewById(R.id.btn_map);

        callPhoneBtn.setOnClickListener(this);
        mapBtn.setOnClickListener(this);
    }

    /**
     * Called when a view has been clicked.
     *
     * @param v The view that was clicked.
     */
    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_call_phone:
                callPhone(CALL_10086);//呼叫10086
                break;
            case R.id.btn_map:
                openMap(MAP_URI);//地图
                break;
            default:
                break;
        }
    }

    /**
     * 电话呼叫
     *
     * @param phoneNumber 电话号码
     */
    private void callPhone(String phoneNumber) {
        if (MyTextUtils.isTrimEmpty(phoneNumber))
            Log.e(LOG_TAG, getString(R.string.parameter_is_empty));
        else {
            Intent callPhoneIntent = new Intent(Intent.ACTION_DIAL, Uri.parse("tel:" + phoneNumber));
            //在intent触发之前，验证是否有APP可以接受当前的intent，否则会引起APP crash（崩溃）
            PackageManager packageManager = getPackageManager();
            List<ResolveInfo> acceptActivityList = packageManager.queryIntentActivities(callPhoneIntent, 0);
            if (acceptActivityList == null || acceptActivityList.size() == 0)
                Log.e(LOG_TAG, "没有APP接受当前intent");
            else
                startActivity(callPhoneIntent);//intent发送给系统后，如果只有一个APP可以接收当前意图，那么会直接打开接收的APP，如果有多个APP可以接收当前intent，那么系统会显示一个Dialog，用户可以选择使用哪个APP开启当前intent
        }
    }

    /**
     * 开启地图
     *
     * @param mapUri 地图链接地址
     */
    private void openMap(String mapUri) {
        if (MyTextUtils.isTrimEmpty(mapUri))
            Log.e(LOG_TAG, getString(R.string.parameter_is_empty));
        else {
            Intent mapIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(mapUri));
            PackageManager packageManager = getPackageManager();
            List<ResolveInfo> resolveInfos = packageManager.queryIntentActivities(mapIntent, 0);
            if (resolveInfos == null || resolveInfos.size() == 0)
                Log.e(LOG_TAG, "open map failed");
            else
                startActivity(mapIntent);
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:orientation="vertical">

    <Button
        android:id="@+id/btn_call_phone"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="呼叫10086"/>

    <Button
        android:id="@+id/btn_map"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="地图"/>
</LinearLayout>