安卓开发之添加loading加载动画

前言

为了用户体验用好，App在网络请求时通常都会显示个进度显示圈圈，提示用户耐心等待，最脍炙人口的莫过于登录啦。

一、实现

1.1、添加图片到drawable

1.2、创建动画

loading.xml

<animated-rotate xmlns:android="http://schemas.android.com/apk/res/android"
                 android:drawable="@drawable/loading_bg"
                 android:pivotX="50%"
                 android:pivotY="50%" />

1.3、创建布局

dialog_loadding.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:alpha="0.4"
    android:background="#000000"
    android:gravity="center"
    android:orientation="vertical"
    android:paddingBottom="20dp"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:paddingTop="20dp">

    <androidx.appcompat.widget.AppCompatImageView
        android:id="@+id/loading"
        android:layout_width="48dp"
        android:layout_height="48dp"
        app:srcCompat="@drawable/loading" />
RelativeLayout>

1.4、创建控制loading的类

package com.example.kbr.utils;

import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.widget.AppCompatImageView;
import android.view.animation.Animation;
import android.widget.ImageView;

/**
 * Created by keranbin on 2017/12/19.
 */

public class LoadingDialog extends Dialog {
    private ObjectAnimator objectAnimator = null;
    private AppCompatImageView circle;
    private long duration = 2000;

    public LoadingDialog(@NonNull Context context) {
        super(context);
    }

    public LoadingDialog(@NonNull Context context, int themeResId) {
        super(context, themeResId);
    }

    protected LoadingDialog(@NonNull Context context, boolean cancelable, @Nullable OnCancelListener cancelListener) {
        super(context, cancelable, cancelListener);
    }

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


    @Override
    public void show() {
        super.show();
        startAnim();
        setOnDismissListener(dialog -> {
            endAnim();
        });
    }

    /**
     * 启动动画
     */
    private void startAnim() {
        setCanceledOnTouchOutside(false);
        circle = findViewById(R.id.loading);
        objectAnimator = ObjectAnimator.ofFloat(circle, "rotation", 0.0f, 360.0f);
        //设置动画时间
        objectAnimator.setDuration(duration);
        //设置动画重复次数，这里-1代表无限
        objectAnimator.setRepeatCount(Animation.INFINITE);
        //设置动画循环模式。
        objectAnimator.setRepeatMode(ValueAnimator.RESTART);
        objectAnimator.start();
    }


    /**
     * 结束动画
     */
    private void endAnim() {
        objectAnimator.end();
        objectAnimator = null;
        circle = null;
    }

}

1.5、调用方法

在需要的地方调用下面的方法

showLoading();  //展示loading动画
clearLoading();  //清除loading动画

        //执行网络耗时任务（这里时模拟）
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(10000);
                    clearLoading();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }).start();

二、测试