Android初体验--设计一个菜单动画

1.目的通过菜单动画项目的设计对Android开发有一个最初的认识和体验，了解相关的知识和技能。

2.代码如下

（1）MainActivity.java

package com.example.day1_menuAnimation;

import android.animation.ObjectAnimator;

import android.os.Bundle;

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import com.google.android.material.snackbar.Snackbar;

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.widget.Toolbar;

import android.view.View;

import android.view.Menu;

import android.view.MenuItem;

import android.view.animation.BounceInterpolator;

import android.widget.ImageView;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

/**

* 1.获取xml里面所有的图片视图

* -先用一个数组保存所有视图的id号 R.id.iv_b

* -用一个数组保存所有id号对应的视图

private int[]resID = {R.id.iv_b,R.id.iv_c,R.id.iv_d,R.id.iv_e,R.id.iv_f,R.id.iv_g,R.id.iv_h};

private ListimageViews=new ArrayList<>();

private boolean isOpen=false;

/**

* 定义一个变量记录按钮的状态

* @param savedInstanceState

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

Toolbar toolbar = findViewById(R.id.toolbar);

setSupportActionBar(toolbar);

FloatingActionButton fab = findViewById(R.id.fab);

fab.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)

.setAction("Action", null).show();

}

});

/**

* 将id号对应图片视图读取出来放到ImageViews里面

for(int i=0;i

int id=resID[i];

ImageView img=findViewById(id);

imageViews.add(img);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.menu_main, menu);

return true;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

// Handle action bar item clicks here. The action bar will

// automatically handle clicks on the Home/Up button, so long

// as you specify a parent activity in AndroidManifest.xml.

int id =item.getItemId();

//noinspection SimplifiableIfStatement

if (id ==R.id.action_settings) {

return true;

}

return super.onOptionsItemSelected(item);

}

public void imgClicked(View view) {

/**

* 判断是打开还是关闭

if(isOpen==true){

close();

}else{

open();

}

isOpen=!isOpen;

}

private void close(){for (int i=0;i

ImageView iv=imageViews.get(i);

ObjectAnimator oa =ObjectAnimator.ofFloat(iv,"translationY",(i+1)*200,0f);

oa.setDuration(1000);

oa.start();

}

private void open () {

for (int i =0; i

ImageView iv =imageViews.get(i);

ObjectAnimator oa =ObjectAnimator.ofFloat(iv, "translationY", 0f, (i +1) *200);

oa.setDuration(1000);

oa.setInterpolator(new BounceInterpolator()); //添加动画弹弹弹

oa.start();

}

}}

(2) content_main.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout 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"

app:layout_behavior="@string/appbar_scrolling_view_behavior"

tools:context=".MainActivity"

tools:showIn="@layout/activity_main">

android:id="@+id/iv_b"

android:layout_width="60dp"

android:layout_height="60dp"

android:src="@mipmap/b" //从素材中取出按键b