Xamarin.Android Binding 源自github第三方库的绑定(中级教学)aar文件

今天来个稍微复杂一点的源自github的android第三方库:CarouselView

(今天我们依然不用在metadata.xml里面写代码，虽然在build时不会有error出现，但是会有烦人的warning出现，导致我们在dll里面找不到我们需要使用的class)

今天我们就是要解决这个问题，这个问题源自这个项目依赖的库

效果图:

今天我们的任务就是把它从Java整成C#,嘿嘿嘿嘿!!!!

CarouselView的Github地址在这里:https://github.com/sayyam/carouselview

1.首先创建项目:  模板--->Android---->单一视图应用(Android)--->名称:CarouselViewProject

　　　　　　自己脑补图片0.0

2.CarouselViewProject--->引用（右键）--->Generate Xamarin.Android Bindings via gradle

从GitHub项目得到Gradle:compile 'com.synnapps:carouselview:0.1.4'

ok-->ok
默认的只勾选第一个aar文件:carouselview-0.1.4.aar剩下的就是这个aar所依赖的jar和aar文件.

3.重新生成项目

你会惊喜的发现，出现不少warning

 　　warning　:　Couldn't load class com/synnapps/carouselview/CarouselView$1 : java.lang.NoClassDefFoundError: android/support/v4/view/ViewPager$OnPageChangeListener

　　什么鬼，这个核心的类，居然无法加载.

4.复制dll文件,然后删除掉自动添加的 绑定库项目 :Binding_CarouselView, 然后在CarouselViewProject项目里引用这个dll文件.

　　在引用里，双击Binding_CarouselView，在对象浏览器里，查看Binding_CarouselView，你会发现一件事情，xamarin你欺骗我，我的类呢0.0？？？？？

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好吧，以上是假教学，下面正式开始今天的教学

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自己脑补假教学的1.2步骤，我们直接从第3步开始.

 

 如何解决这类waring呢？--warning　:　Couldn't load class com/synnapps/carouselview/CarouselView$1 : java.lang.NoClassDefFoundError: android/support/v4/view/ViewPager$OnPageChangeListener

 

其实这是一个依赖的问题，你注意到第三张图片里有好多未打勾的aar，jar文件了吗？这就是这个库所依赖的文件.

但是我们并不会打勾这些aar，jar文件，那我们如何引用这些库呢？

 

3. 其实这些都是android文件，而且Xamarin官方已经帮我们做好了dll文件，我们只需要在解决方案里，为 app，android binding library两个项目添加上这些nuget包即可，同时需要注意nuget包的版本和图三匹配（尽量做到匹配）

Nuget包:

Xamarin.Android.Support.v7.RecyclerView (25.1.0版本)

 Xamarin.Android.Support.v7.AppCompat(25.1.0版本)

Xamarin.Android.Support.v4(25.1.0版本)

Xamarin.Android.Support.Annotations（好像并没有25.1.0版本，直接选择最新稳定版即可25.4.0.2）

虽然我们只选择了这四个包安装，但是因为nuget包之间有依赖关系，最终我们会安装上11个nuget包.

4.Build整个解决方案,取走Binding_CarouselView的Binding_CarouselView.dll文件----（文件地址CarouselViewProject\CarouselViewProject\AndroidBindings\Binding_CarouselView\bin\Debug）

(保存好这个dll)

 

5.先删除Binding_CarouselView项目，然后在CarouselViewProject项目的引用里添加刚才我们保存的Binding_CarouselView.dll

 

6.一切准备就绪，让我们开始使用这个 Com.Synnapps.Carouselview吧

 让我们先看一下github的介绍，或者去sample项目浏览一下Java是怎么做的，然后我们要把它的代码变成C#!

如同周伯通，左手画方，右手画圆.

Github上面的代码，作者是这么写的:

Java版本

Usage

Include following code in your layout:


    <com.synnapps.carouselview.CarouselView
        android:id="@+id/carouselView"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        app:fillColor="#FFFFFFFF"
        app:pageColor="#00000000"
        app:radius="6dp"
        app:slideInterval="3000"
        app:strokeColor="#FF777777"
        app:strokeWidth="1dp"/>


Include following code in your activity:

public class SampleCarouselViewActivity extends AppCompatActivity {

    CarouselView carouselView;

    int[] sampleImages = {R.drawable.image_1, R.drawable.image_2, R.drawable.image_3, R.drawable.image_4, R.drawable.image_5};

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

        carouselView = (CarouselView) findViewById(R.id.carouselView);
        carouselView.setPageCount(sampleImages.length);

        carouselView.setImageListener(imageListener);
    }

    ImageListener imageListener = new ImageListener() {
        @Override
        public void setImageForPosition(int position, ImageView imageView) {
            imageView.setImageResource(sampleImages[position]);
        }
    };

}

C#版本

一.我们先找到5张图片放到Resources\drawable文件夹里面.(我直接使用github上面的5张图片)

二.在layout/Main.axml 里面填写以下xml代码

<?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:layout_width="match_parent"
    android:layout_height="match_parent">
  <com.synnapps.carouselview.CarouselView
      android:id="@+id/myCarouselView"
      android:layout_width="match_parent"
      android:layout_height="200dp"
      app:fillColor="#FFFFFFFF"
      app:pageColor="#00000000"
      app:radius="6dp"
      app:slideInterval="3000"
      app:strokeColor="#FF777777"
      app:strokeWidth="1dp" />
</LinearLayout>

三.在MainActivity.cs填写以下代码

using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Com.Synnapps.Carouselview;

namespace CarouselViewProject
{
    [Activity(Label = "CarouselViewProject", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity, IImageListener
    {
        CarouselView myCarouselView;
        int[] sampleImages = { Resource.Drawable.image_1, Resource.Drawable.image_2, Resource.Drawable.image_3, Resource.Drawable.image_4, Resource.Drawable.image_5 };

        public void SetImageForPosition(int p0, ImageView p1)
        {
            p1.SetImageResource(sampleImages[p0]);
        }

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);
            myCarouselView = (CarouselView)FindViewById<CarouselView>(Resource.Id.myCarouselView);
            myCarouselView.PageCount = sampleImages.Length;
            myCarouselView.SetImageListener(this);
        }
    }
}

四.运行，效果图如下

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让我们接着跟着github作者的步骤走，提升以下难度,这次我们要自定义轮播喽,在图片左上角 增加文字和点击事件

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Java版本:

If you want to add custom view, implement ViewListener.

public class SampleCarouselViewActivity extends AppCompatActivity {

    CarouselView customCarouselView;
    int NUMBER_OF_PAGES = 5;

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

        customCarouselView = (CarouselView) findViewById(R.id.customCarouselView);
        customCarouselView.setPageCount(NUMBER_OF_PAGES);
        // set ViewListener for custom view 
        customCarouselView.setViewListener(viewListener);
    }

    ViewListener viewListener = new ViewListener() {
    
        @Override
        public View setViewForPosition(int position) {
            View customView = getLayoutInflater().inflate(R.layout.view_custom, null);
            //set view attributes here
            
            return customView;
        }
    };

If you'd like to receive touch events for each image

customCarouselView.setImageClickListener(new ImageClickListener() {
            @Override
            public void onClick(int position) {
                Toast.makeText(SampleCarouselViewActivity.this, "Clicked item: "+ position, Toast.LENGTH_SHORT).show();
            }
        });

 C#版本:

一.layout,右键，添加，新建项，Android布局,view_custom.axml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center">
    <ImageView
        android:id="@+id/fruitImageView"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:scaleType="centerCrop" />
    <TextView
        android:id="@+id/labelTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"
        android:layout_marginTop="30dp"
        android:textSize="24sp"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:paddingTop="5dp"
        android:paddingBottom="5dp"
        android:background="#44FFFFFF"
        android:fontFamily="sans-serif-thin"
        android:textColor="@android:color/white"/>
</RelativeLayout>

二.修改Main.axml

<?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:layout_width="match_parent"
    android:layout_height="match_parent">
    <com.synnapps.carouselview.CarouselView
        android:id="@+id/customCarouselView"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        app:fillColor="#FFFFFFFF"
        app:pageColor="#00000000"
        app:radius="6dp"
        app:slideInterval="3000"
        app:strokeColor="#FF777777"
        app:strokeWidth="1dp" />
</LinearLayout>

三.修改MainActivity.cs

using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Com.Synnapps.Carouselview;

namespace CarouselViewProject
{
    [Activity(Label = "CarouselViewProject", MainLauncher = true, Icon = "@drawable/icon")]
    public class MainActivity : Activity, IViewListener, IImageClickListener
    {
        CarouselView customCarouselView;

        int[] sampleImages = { Resource.Drawable.image_1, Resource.Drawable.image_2, Resource.Drawable.image_3, Resource.Drawable.image_4, Resource.Drawable.image_5 };
        String[] sampleTitles = { "Orange", "Grapes", "Strawberry", "Cherry", "Apricot" };


        public void OnClick(int p0)
        {
            Toast.MakeText(ApplicationContext, sampleTitles[p0], ToastLength.Long).Show();
        }


        public View SetViewForPosition(int p0)
        {
            View customView = this.LayoutInflater.Inflate(Resource.Layout.view_custom, null);
            TextView labelTextView = (TextView)customView.FindViewById(Resource.Id.labelTextView);
            ImageView fruitImageView = (ImageView)customView.FindViewById(Resource.Id.fruitImageView);

            labelTextView.Text=sampleTitles[p0];
            fruitImageView.SetImageResource(sampleImages[p0]);

            return customView;
        }

        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);

            customCarouselView = (CarouselView)FindViewById<CarouselView>(Resource.Id.customCarouselView);
            customCarouselView.PageCount = sampleImages.Length;
            customCarouselView.SetViewListener(this);
            customCarouselView.SetImageClickListener(this);
        }
    }
}

效果图:

再见0.0