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

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

<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
}

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