The difference between class and getClass ()

Hello everyone , I meet you again , I'm your friend, Quan Jun .

I was working on a project the other day , I feel that I have been developing for more than a year , There is no self encapsulated class , I feel like I did it in vain , Plus , See your own code , I can't bear to see it , sometimes , You also need to read your own code , Messy , I really can't bear to see , Can't , Reappear at the beginning , Put what you need , It's all encapsulated , When to use , Where can I use it , convenient , quick

The first is the base class encapsulated by itself baseActivity, Don't bullshit , Go straight to the code （ The rest will not be posted , Only this place has mistakes ）

package com.demo.XXX.XX.base;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.IBinder;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;

import com.demo.XXX.XXX.tools.LogUtil;
import com.demo.XXX.XXX.tools.ShareUtils;

/**
 * Created by XXX on 2016/9/26.
 */
public abstract class BaseActivity extends Activity {

    private String TAG;
    protected Context context;
    protected ShareUtils shareUtils;
    protected LayoutInflater inflater;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        context = this;
        inflater = LayoutInflater.from(context);
        TAG = getClass().getName();
        LogUtil.i("BaseActivity", TAG);
        shareUtils = new ShareUtils(context);

    }

    /**
     *  Initialize control or data 
     */
    protected abstract void initView();

    /**
     *  Initialize click events 
     */
    protected abstract void setListener();

    /**
     *  Single activity The jump 
     *
     * @param mClass  Jump class 
     */
    public void start_activity(Class<?> mClass) {
        startActivity(new Intent(context, mClass.getClass()));
    }

    /**
     *  Jump with pass parameters 
     *
     * @param mClass  Jump class 
     * @param key     Jump key value 
     * @param value   Jump value value 
     */
    public void start_activity(Class<?> mClass, String key, String value) {
        startActivity(new Intent(context, mClass).putExtra(key, value));
    }

    /**
     *  Jump with pass parameters 
     *
     * @param mClass  Jump class 
     * @param key     Jump key value 
     * @param value   Jump value value 
     */
    public void start_activity(Class<?> mClass, String key, int value) {
        startActivity(new Intent(context, mClass).putExtra(key, value));
    }

    /**
     *  Jump with pass parameters 
     *
     * @param mClass  Jump class 
     * @param key     Jump key value 
     * @param value   Jump value value 
     */
    public void start_activity(Class<?> mClass, String key, Bundle value) {
        startActivity(new Intent(context, mClass).putExtra(key, value));
    }

    /***
     *  Click on the blank space   Hide soft keyboard 
     * @param ev
     * @return
     */
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (ev.getAction() == MotionEvent.ACTION_DOWN) {
            View v = getCurrentFocus();
            if (isShouldHideKeyboard(v, ev)) {
                hideKeyboard(v.getWindowToken());
            }
        }
        return super.dispatchTouchEvent(ev);
    }

    /**
     *  according to EditText The coordinates are compared with the coordinates clicked by the user , To determine whether to hide the keyboard , Because when the user clicks EditText You can't hide 
     *
     * @param v
     * @param event
     * @return
     */
    private boolean isShouldHideKeyboard(View v, MotionEvent event) {
        if (v != null && (v instanceof EditText)) {
            int[] l = {0, 0};
            v.getLocationInWindow(l);
            int left = l[0],
                    top = l[1],
                    bottom = top + v.getHeight(),
                    right = left + v.getWidth();
            if (event.getX() > left && event.getX() < right
                    && event.getY() > top && event.getY() < bottom) {
                //  Click on EditText Events , Ignore it .
                return false;
            } else {
                return true;
            }
        }
        //  If the focus is not EditText It ignores , This happens when the view has just been drawn , The first focus is not on EditText On , And the user selects another focus with the trackball 
        return false;
    }

    /**
     *  obtain InputMethodManager, Hide soft keyboard 
     *
     * @param token
     */
    private void hideKeyboard(IBinder token) {
        if (token != null) {
            InputMethodManager im = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
            im.hideSoftInputFromWindow(token, InputMethodManager.HIDE_NOT_ALWAYS);
        }
    }
}

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I thought I encapsulated well , Very satisfied , ha-ha , I also have my own encapsulated code , In the future, it will be improved , Directly use this framework to do projects , That's not swishing , I think Kaisen

Start using activity When you jump around , It's encapsulated by itself start_activity Method , As a result, a basin of cold water poured on my head , Direct error

 android.content.ActivityNotFoundException: Unable to find explicit activity class {com.demo.neu/java.lang.Class};

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 have you declared this activity in your AndroidManifest.xml?

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Can't find this class ？ I'm already in androidManifest It's registered inside , Why does it prompt that this class cannot be found , try Google Provided startac Method , have a look

Can jump , Why , I can't jump in my package , There is no problem , hold androidManifest Delete the type inside , Use... Again Google Of startactivity Methods do jump to see , The result is wrong

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.demo.XXX/com.demo.XXX.XXX.

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activity.LoginActivity}; have you declared this activity in your AndroidManifest.xml?

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Why , The mistake is different , ok , It's not that the class is not registered , Let's take a look at our own packaging methods , When I looked carefully, I found , The original problem is here

    /**
     *  Single activity The jump 
     *
     * @param mClass  Jump class 
     */
    public void start_activity(Class<?> mClass) {
        startActivity(new Intent(context, mClass.getClass()));
    }

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And the lower package

/**
     *  Jump with pass parameters 
     *
     * @param mClass  Jump class 
     * @param key     Jump key value 
     * @param value   Jump value value 
     */
    public void start_activity(Class<?> mClass, String key, String value) {
        startActivity(new Intent(context, mClass).putExtra(key, value));
    }

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Where is the single jump used class.getClass(), Get rid of getClass（）, The successful running , You can jump , So here comes the question ,class and getClass（） What's the difference ,

Careful you may have found , That's the problem

com.demo.neu/java.lang.Class

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and

com.demo.XXX/com.demo.XXX.XXX.activity.LoginActivity

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That's the problem , The error report in front is java Inside long type , Because in long There is no loginActivity This class , So there's a mistake , Then there is a specific class specified , That is to say, No androidMainfest There is no registration inside

One is the class inside the type , One is concrete activity Class , Of course, the mistake is different , Of course there is a problem

I stepped on the pit for you , I'll pay attention to it in the future , Don't make me such a low-level mistake again , alas

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