Android实现仿慕课网下拉加载动画

具体实现方法就不多介绍了先附上源码，相信大家都容易看的懂：

这里为了让这个动画效果可被复用，于是就继承了ImageView 去实现某些方法

package com.example.loading_drawable;

import android.content.Context;
import android.graphics.drawable.AnimationDrawable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.animation.Animation;
import android.widget.ImageView;

public class MyImgView extends ImageView {
// 动画图层类
private AnimationDrawable bg_anim;

public MyImgView(Context context) {
super(context, null);
initView();
}

public MyImgView(Context context, AttributeSet attrs) {
super(context, attrs, 0);
}

public MyImgView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);

}
　　//初始化
private void initView() {
setBackgroundResource(R.drawable.flash_anim);
bg_anim = (AnimationDrawable) getBackground();
Log.i("AAA", "iniView");
}


public void startAnim() {
if (bg_anim != null) {
 bg_anim.start();
}
}


public void stopAnim() {
if (bg_anim != null && bg_anim.isRunning()) {
 bg_anim.stop();
}
}


@Override
public void setVisibility(int visibility) {
super.setVisibility(visibility);
if (visibility == View.VISIBLE) {
 startAnim();
} else {
 stopAnim();
}
}

}

 接下来就是：在res文件夹下新建 drawable文件夹，再此文件夹下新建 flash_anim.xml文件，具体如下：

这样就基本搞定了，接下来就要在main中调用自定义的main就可以;如下：

package com.example.loading_drawable;

import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;


public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 LinearLayout rootLayout = new LinearLayout(this);
 rootLayout.setOrientation(LinearLayout.VERTICAL);
 rootLayout.setLayoutParams(new LinearLayout.LayoutParams(
   LinearLayout.LayoutParams.MATCH_PARENT,
   LinearLayout.LayoutParams.MATCH_PARENT));
 rootLayout.setGravity(Gravity.CENTER);

 Button btn = new Button(this);
 btn.setText("展现动画");

 final MyImgView imgView = new MyImgView(MainActivity.this);
 imgView.setLayoutParams(new LinearLayout.LayoutParams(
   LinearLayout.LayoutParams.WRAP_CONTENT,
   LinearLayout.LayoutParams.WRAP_CONTENT));
 imgView.setVisibility(View.GONE);

 rootLayout.addView(btn);
 rootLayout.addView(imgView);

 setContentView(rootLayout);

 btn.setonClickListener(new onClickListener() {

  @Override
  public void onClick(View arg0) {
   imgView.setVisibility(View.VISIBLE);
  }
 });
}
}

这里是用自定义代码布局文件做的，布局方便，插件代码整合，如上所述，这个动画就完成了，只在需要的地方设置imgview为显示，动画就会开启，隐藏动画就会被关闭。

具体内容到此为止，希望大家能够喜欢。