Android通用LoadingView加载框架

手写一个通用加载中、显示数据、加载失败、空数据的LoadingView框架。

定义3个布局：加载中，加载失败，空数据

加载中:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffffff"
    android:clickable="true">

    <ProgressBar
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:indeterminate="true" />

</FrameLayout>

加载失败:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffffff"
    android:clickable="true"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/error_retry"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:gravity="center"
        android:src="@drawable/loading_retry" />

</FrameLayout>

空数据:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffffff"
    android:clickable="true"
    android:orientation="vertical">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:src="@drawable/loading_empty" />

</FrameLayout>

自定义一个LoadingView:

package com.sample.loadingview.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.support.annotation.AttrRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.SparseArray;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;

import com.sample.loadingview.R;


public class LoadingView extends FrameLayout {
    private int emptyLayoutId, errorLayoutId, loadingLayoutId;
    private View contentView, emptyView, errorView, loadingView;
    private LayoutInflater mInflater;
    private SparseArray<View> views = new SparseArray<>();

    public LoadingView(@NonNull Context context) {
        this(context, null);
    }

    public LoadingView(@NonNull Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public LoadingView(@NonNull Context context, @Nullable AttributeSet attrs, @AttrRes int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.LoadLayout);
        emptyLayoutId = a.getResourceId(R.styleable.LoadLayout_emptyView, R.layout.loading_empty);
        errorLayoutId = a.getResourceId(R.styleable.LoadLayout_errorView, R.layout.loading_error);
        loadingLayoutId = a.getResourceId(R.styleable.LoadLayout_loadingView, R.layout.loading_load);
        mInflater = LayoutInflater.from(getContext());
        a.recycle();
        loadingView = mInflater.inflate(loadingLayoutId, null);
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        if (getChildCount() < 1) {
            throw new RuntimeException("content view can not be null");
        }
        contentView = getChildAt(0);

        if (loadingView.getVisibility() != GONE)
            loadingView.setVisibility(GONE);
        addView(loadingView);
        views.put(loadingLayoutId, loadingView);
    }

    public void showError() {
        errorView = views.get(errorLayoutId);
        if (errorView == null) {
            errorView = mInflater.inflate(errorLayoutId, null);
            addView(errorView);
            views.put(errorLayoutId, errorView);
            final ImageView errorRetry = (ImageView) errorView.findViewById(R.id.error_retry);
            errorRetry.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (mOnRetryClickListener != null)
                        mOnRetryClickListener.onClick(errorRetry);
                }
            });
        }
        if (errorView.getVisibility() != VISIBLE)
            errorView.setVisibility(VISIBLE);

        for (int i = 0, len = views.size(); i < len; i++) {
            int key = views.keyAt(i);
            if (key != errorLayoutId) {
                View view = views.valueAt(i);
                if (view != null)
                    if (view.getVisibility() != GONE)
                        view.setVisibility(GONE);
            }
        }
    }

    public void showEmpty() {
        emptyView = views.get(emptyLayoutId);
        if (emptyView == null) {
            emptyView = mInflater.inflate(emptyLayoutId, null);
            addView(emptyView);
            views.put(emptyLayoutId, emptyView);
        }
        if (emptyView.getVisibility() != VISIBLE)
            emptyView.setVisibility(VISIBLE);

        for (int i = 0, len = views.size(); i < len; i++) {
            int key = views.keyAt(i);
            if (key != emptyLayoutId) {
                View view = views.valueAt(i);
                if (view != null)
                    if (view.getVisibility() != GONE)
                        view.setVisibility(GONE);
            }
        }
    }

    public void showLoading() {
        loadingView = views.get(loadingLayoutId);
        if (loadingView.getVisibility() != VISIBLE)
            loadingView.setVisibility(VISIBLE);

        for (int i = 0, len = views.size(); i < len; i++) {
            int key = views.keyAt(i);
            if (key != loadingLayoutId) {
                View view = views.valueAt(i);
                if (view != null)
                    if (view.getVisibility() != GONE)
                        view.setVisibility(GONE);
            }
        }
    }

    public void showContent() {
        for (int i = 0, len = views.size(); i < len; i++) {
            View view = views.valueAt(i);
            if (view != null)
                if (view.getVisibility() != GONE)
                    view.setVisibility(GONE);
        }
    }

    private OnClickListener mOnRetryClickListener;

    public void setOnRetryClickListener(OnClickListener onRetryClickListener) {
        this.mOnRetryClickListener = onRetryClickListener;
    }
}

定义attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="LoadLayout">
        <attr name="loadingView" format="reference" />
        <attr name="errorView" format="reference" />
        <attr name="retryView" format="reference" />
        <attr name="emptyView" format="reference" />
    </declare-styleable>
</resources>

以上就这么些代码，接下来我们测试一下

Activity

package com.sample.loadingview;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import com.sample.loadingview.widget.LoadingView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private LoadingView loading_view;
    private Button btn_loading;
    private Button btn_content;
    private Button btn_error;
    private Button btn_empty;

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

        loading_view = (LoadingView) findViewById(R.id.loading_view);
        btn_loading = (Button) findViewById(R.id.btn_loading);
        btn_content = (Button) findViewById(R.id.btn_content);
        btn_error = (Button) findViewById(R.id.btn_error);
        btn_empty = (Button) findViewById(R.id.btn_empty);

        //设置加载错误的点击事件
        loading_view.setOnRetryClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "重新加载", Toast.LENGTH_SHORT).show();
                loading_view.showLoading();
            }
        });
        btn_loading.setOnClickListener(this);
        btn_content.setOnClickListener(this);
        btn_error.setOnClickListener(this);
        btn_empty.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_loading:
                loading_view.showLoading();//显示加载界面
                break;
            case R.id.btn_content:
                loading_view.showContent();//显示内容界面
                break;
            case R.id.btn_error:
                loading_view.showError();//显示错误界面
                break;
            case R.id.btn_empty:
                loading_view.showEmpty();//显示空数据界面
                break;
        }
    }
}

代码下载