在Android中创建类似Instagram的渐变背景

1.gif

我在我最近的项目用到这个效果，给大家分享下
https://github.com/zhaoweihaoChina/hnuplus

1. 在drawable文件夹创建一些渐变颜色的资源

color1.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#614385"
        android:endColor="#516395"
        android:angle="0"/>
</shape>

color2.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#5f2c82"
        android:endColor="#49a09d"
        android:angle="45"/>
</shape>

color3.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#4776E6"
        android:endColor="#8E54E9"
        android:angle="90"/>
</shape>

color4.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:startColor="#7141e2"
        android:endColor="#d46cb3"
        android:angle="135"/>
</shape>

2. 创建一个用到上面创建的渐变色的动画序列，命名为animation_list.xml,放进去drawable文件夹

<?xml version="1.0" encoding="utf-8"?>
<animation-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:drawable="@drawable/color1"
        android:duration="10000" />
    <item
        android:drawable="@drawable/color2"
        android:duration="10000" />
    <item
        android:drawable="@drawable/color3"
        android:duration="10000" />
    <item
        android:drawable="@drawable/color4"
        android:duration="10000" />
</animation-list>

3. 将上面已经创建好的动画序列应用到你layout的背景顶层的view中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@drawable/animation_list"
    android:id="@+id/container">

    <!-- Child Views -->

</LinearLayout>

4.在你的activity中用AnimationDrawable去实现过渡效果

LinearLayout container = (LinearLayout) findViewById(R.id.container);

AnimationDrawable anim = (AnimationDrawable) container.getBackground();
anim.setEnterFadeDuration(6000);
anim.setExitFadeDuration(2000);

// 开始播放动画：在onResume方法中开始播放渐变动画
@Override
protected void onResume() {
    super.onResume();
    if (anim != null && !anim.isRunning())
        anim.start();
}
      
// 停止播放动画：在onPause方法中停止播放渐变动画
@Override
protected void onPause() {
    super.onPause();
    if (anim != null && anim.isRunning())
        anim.stop();
}

将状态栏设置透明（去除状态栏）

values/styles.xml

<resources>  
    <style name="Theme.AppTheme.TranslucentStatusBar" parent="Theme.AppCompat.Light.NoActionBar" />  
</resources>  

values-v19/styles.xml

<resources>  
    <style name="Theme.AppTheme.TranslucentStatusBar" parent="Theme.AppCompat.Light.NoActionBar">  
        <item name="android:windowTranslucentStatus">true</item>  
    </style>  
</resources> 

values-v21/styles.xml

<resources>  
    <style name="Theme.AppTheme.TranslucentStatusBar" parent="Theme.AppCompat.Light.NoActionBar">  
        <item name="android:statusBarColor">@android:color/transparent</item>  
    </style>  
</resources>  

values-v23/styles.xml

<resources>  
    <style name="Theme.AppTheme.TranslucentStatusBar" parent="Theme.AppCompat.Light.NoActionBar">  
        <item name="android:statusBarColor">@android:color/transparent</item>  
        <item name="android:windowLightStatusBar">true</item>  
    </style>  
</resources> 

public class MainActivity extends AppCompatActivity {  
  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
  
        // 加入下面的代码
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {  
            findViewById(android.R.id.content).setSystemUiVisibility(  
                    View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);  
        }  
  
        setContentView(R.layout.activity_splash);  
    }  
}  

<activity  
    android:name=".MainActivity"  
    android:theme="@style/Theme.AppTheme.TranslucentStatusBar" /> 

联系

邮箱：zhaoweihaochn@foxmail.com

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