自定义带进度的ProgressRelativeLayout，实现加载网络数据时有进度条样式

第一步：自定义一个ProgressRelativeLayout类，如下

package com.example.view;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Color;import android.text.TextUtils;import android.util.AttributeSet;import android.view.Gravity;import android.view.View;import android.view.ViewGroup;import android.widget.LinearLayout;import android.widget.ProgressBar;import android.widget.RelativeLayout;import android.widget.TextView;import com.example.R;import java.util.ArrayList;import java.util.Collections;import java.util.List;public class ProgressRelativeLayout extends RelativeLayout {    private static final String TAG_PROGRESS = "ProgressLayout.TAG_PROGRESS";    private static final String TAG_ERROR = "ProgressLayout.TAG_ERROR";    public static enum State {        CONTENT, PROGRESS, ERROR    }    private View mProgressView;    private TextView mErrorTextView;    private List<View> mContentViews = new ArrayList<View>();    private State mState = State.CONTENT;    public ProgressRelativeLayout(Context context) {        super(context);    }    public ProgressRelativeLayout(Context context, AttributeSet attrs) {        super(context, attrs);        init(attrs);    }    public ProgressRelativeLayout(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        init(attrs);    }    private void init(AttributeSet attrs) {        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.ProgressRelativeLayout);        int backgroundColor = a.getColor(R.styleable.ProgressRelativeLayout_progressBackground, Color.TRANSPARENT);        boolean progress = a.getBoolean(R.styleable.ProgressRelativeLayout_progress, false);        a.recycle();        LayoutParams layoutParams;        // if progressBackground color == Color.TRANSPARENT just add progress bar        if (backgroundColor == Color.TRANSPARENT) {            mProgressView = new ProgressBar(getContext());            layoutParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);            layoutParams.addRule(CENTER_IN_PARENT);        } else { // else wrap progress bar in LinearLayout and set background color to LinearLayout            LinearLayout linearLayout = new LinearLayout(getContext());            linearLayout.setGravity(Gravity.CENTER);            linearLayout.setBackgroundColor(backgroundColor);            layoutParams = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);            ProgressBar progressBar = new ProgressBar(getContext());            linearLayout.addView(progressBar);            mProgressView = linearLayout;        }        mProgressView.setTag(TAG_PROGRESS);        addView(mProgressView, layoutParams);        // add error text view        mErrorTextView = new TextView(getContext());        mErrorTextView.setTag(TAG_ERROR);        layoutParams = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);        layoutParams.addRule(CENTER_IN_PARENT);        addView(mErrorTextView, layoutParams);        mProgressView.setVisibility(progress ? VISIBLE : GONE);    }    @Override    public void addView(View child, int index, ViewGroup.LayoutParams params) {        super.addView(child, index, params);        if (child.getTag() == null || (!child.getTag().equals(TAG_PROGRESS) && !child.getTag().equals(TAG_ERROR))) {            mContentViews.add(child);        }    }    public void showProgress() {        switchState(State.PROGRESS, null, Collections.<Integer>emptyList());    }    public void showProgress(List<Integer> skipIds) {        switchState(State.PROGRESS, null, skipIds);    }    public void showErrorText() {        switchState(State.ERROR, null, Collections.<Integer>emptyList());    }    public void showErrorText(List<Integer> skipIds) {        switchState(State.ERROR, null, skipIds);    }    public void showErrorText(String error) {        switchState(State.ERROR, error, Collections.<Integer>emptyList());    }    public void showErrorText(String error, List<Integer> skipIds) {        switchState(State.ERROR, error, skipIds);    }    public void showContent() {        switchState(State.CONTENT, null, Collections.<Integer>emptyList());    }    public void showContent(List<Integer> skipIds) {        switchState(State.CONTENT, null, skipIds);    }    public void switchState(State state) {        switchState(state, null, Collections.<Integer>emptyList());    }    public void switchState(State state, String errorText) {        switchState(state, errorText, Collections.<Integer>emptyList());    }    public void switchState(State state, List<Integer> skipIds) {        switchState(state, null, skipIds);    }    public void switchState(State state, String errorText, List<Integer> skipIds) {        mState = state;        switch (state) {            case CONTENT:                mErrorTextView.setVisibility(View.GONE);                mProgressView.setVisibility(View.GONE);                setContentVisibility(true, skipIds);                break;            case PROGRESS:                mErrorTextView.setVisibility(View.GONE);                mProgressView.setVisibility(View.VISIBLE);                setContentVisibility(false, skipIds);                break;            case ERROR:                if (TextUtils.isEmpty(errorText)) {                    mErrorTextView.setText(R.string.unknown_error);                } else {                    mErrorTextView.setText(errorText);                }                mErrorTextView.setVisibility(View.VISIBLE);                mProgressView.setVisibility(View.GONE);                setContentVisibility(false, skipIds);                break;        }    }    public State getState() {        return mState;    }    public boolean isProgress() {        return mState == State.PROGRESS;    }    public boolean isContent() {        return mState == State.CONTENT;    }    public boolean isError() {        return mState == State.ERROR;    }    private void setContentVisibility(boolean visible, List<Integer> skipIds) {        for (View v : mContentViews) {            if (!skipIds.contains(v.getId())) {                v.setVisibility(visible ? View.VISIBLE : View.GONE);            }        }    }}

第二步：在布局文件中需要网络请求的地方引用

<?xml version="1.0" encoding="utf-8"?><com.example.view.ProgressRelativeLayout    xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/progress_layout"    android:layout_width="match_parent"    android:layout_height="match_parent">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="match_parent"        android:background="@color/white"        android:orientation="vertical">        <span style="white-space:pre"></span>...    </LinearLayout></com.example.view.ProgressRelativeLayout>

第三步：在初始化布局时显示进度并开始加载网络数据，根据加载的状态取消进度，并显示相应信息

显示进度

  _progressLinearLayout = (ProgressRelativeLayout)findViewById(R.id.progress_layout);  _progressLinearLayout.showProgress();

在加载网络数据失败的回调中，显示错误信息

      <span style="white-space:pre"></span>    @Override            public void onFailure(Response resp, Throwable e) {                String msg = getString(R.string.film_collect_get_error);                _progressLinearLayout.showErrorText(msg);//在此方法的最后调用            }

在加载网络数据成功的回调中，显示数据

 <span style="white-space:pre"></span>    @Override            public void onSuccess(Response resp) {                //在此方法的最后调用                _progressLinearLayout.showContent();            }