package com.loaderman.customviewdemo;

import android.graphics.drawable.Animatable;

import android.os.Bundle;

import android.support.graphics.drawable.AnimatedVectorDrawableCompat;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.app.AppCompatDelegate;

import android.view.View;

import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    static {

        AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);

    }

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        findViewById(R.id.btn).setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                ImageView imageView = (ImageView) findViewById(R.id.anim_img);

                AnimatedVectorDrawableCompat animatedVectorDrawableCompat = AnimatedVectorDrawableCompat.create(

                        MainActivity.this, R.drawable.line_animated_vector

                );

                imageView.setImageDrawable(animatedVectorDrawableCompat);

                ((Animatable) imageView.getDrawable()).start();

            }

        });

    }

}

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

<LinearLayout

    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:orientation="vertical"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    >

    <Button

        android:id="@+id/btn"

        android:text="开始动画"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        />

    <ImageView

        android:id="@+id/anim_img"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        app:srcCompat="@drawable/svg_line"/>

</LinearLayout>

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

<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"

        android:drawable="@drawable/svg_line">

    <target

            android:name="bar"

            android:animation="@animator/anim_trim_start"

            />

</animated-vector>

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

<objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"

        android:propertyName="trimPathStart"

        android:valueFrom="0"

        android:valueTo="1"

        android:duration="2000"/>

package com.loaderman.customviewdemo;

import android.graphics.drawable.Animatable;

import android.os.Bundle;

import android.support.graphics.drawable.AnimatedVectorDrawableCompat;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.app.AppCompatDelegate;

import android.view.View;

import android.widget.EditText;

import android.widget.ImageView;

public class MainActivity extends AppCompatActivity {

    static {

        AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);

    }

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        final ImageView imageView = (ImageView) findViewById(R.id.anim_img);

        //将焦点放在ImageView上

        imageView.setFocusable(true);

        imageView.setFocusableInTouchMode(true);

        imageView.requestFocus();

        imageView.requestFocusFromTouch();

        EditText editText = (EditText)findViewById(R.id.edit);

        //当EditText获得焦点时开始动画

        editText.setOnFocusChangeListener(new View.OnFocusChangeListener() {

            @Override

            public void onFocusChange(View v, boolean hasFocus) {

                if (hasFocus){

                    AnimatedVectorDrawableCompat animatedVectorDrawableCompat = AnimatedVectorDrawableCompat.create(

                            MainActivity.this, R.drawable.animated_vecotr_search

                    );

                    imageView.setImageDrawable(animatedVectorDrawableCompat);

                    ((Animatable) imageView.getDrawable()).start();

                }

            }

        });

    }

}

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

<animated-vector xmlns:android="http://schemas.android.com/apk/res/android"

    android:drawable="@drawable/vector_search_bar" >

    <target

        android:animation="@animator/anim_search_trim_end"

        android:name="search"/>

    <target

        android:animation="@animator/anim_bar_trim_start"

        android:name="bar"/>

</animated-vector>

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

<vector xmlns:android="http://schemas.android.com/apk/res/android"

    android:width="150dp"

    android:height="24dp"

    android:viewportWidth="150"

    android:viewportHeight="24">

    <!--搜索条-->

    <path

        android:name="search"

        android:pathData="M141,17 A9,9 0 1,1 142,16 L149,23"

        android:strokeWidth="2"

        android:strokeColor="@android:color/darker_gray"/>

    <!--底部横线-->

    <path

        android:name="bar"

        android:trimPathStart="1"

        android:pathData="M0,23 L149,23"

        android:strokeWidth="2"

        android:strokeColor="@android:color/darker_gray"/>

</vector>

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

<objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"

    android:duration="500"

    android:propertyName="trimPathEnd"

    android:valueFrom="0"

    android:valueTo="1"

    android:valueType="floatType" />

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

<FrameLayout

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:orientation="vertical"

    android:layout_marginTop="20dp"

    android:layout_marginLeft="20dp"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    >

    <EditText

        android:id="@+id/edit"

        android:hint="点击输入"

        android:layout_width="150dp"

        android:layout_height="24dp"

        android:background="@null"/>

    <ImageView

        android:id="@+id/anim_img"

        android:layout_width="150dp"

        android:layout_height="24dp"

        />

</FrameLayout>