15.瀑布流、測量

排行界面

TopProtocol?：json數據就是寫字符串，所以不需要寫bean對象

public class TopProtocol extends BaseProtocol<List<String>> {
@Override
public List<String> paserJson(String json) {
List<String> datas=new ArrayList<String>();
try {
JSONArray array=new JSONArray(json);
for(int i=0;i<array.length();i++){
String str=array.getString(i);
datas.add(str);
}
return datas;
} catch (JSONException e) {
e.printStackTrace();
return null;
}
}
@Override
public String getKey() {
return "hot";
}
}

DrawableUtils?：用代碼創建狀態選擇器和圓角

public class DrawableUtils {
public static GradientDrawable createShape(int color){
GradientDrawable drawable=new GradientDrawable();//相當于shape
drawable.setCornerRadius(UiUtils.dip2px(5));//設置4個角的弧度
drawable.setColor(color);// 設置顏色
return drawable;
}
public static StateListDrawable createSelectorDrawable(Drawable pressedDrawable,Drawable normalDrawable){
// <selector xmlns:android="http://schemas.android.com/apk/res/android" android:enterFadeDuration="200">
// <item android:state_pressed="true" android:drawable="@drawable/detail_btn_pressed"></item>
// <item android:drawable="@drawable/detail_btn_normal"></item>
// </selector>
StateListDrawable stateListDrawable=new StateListDrawable();
stateListDrawable.addState(new int[]{android.R.attr.state_pressed}, pressedDrawable);// 按下顯示的圖片
stateListDrawable.addState(new int[]{}, normalDrawable);// 抬起顯示的圖片
return stateListDrawable;
}
}

TopFragment?：使用代碼創建、隨機色

MATCH_PARENT?、FILL_PARENT是-1且他倆個沒有任何區別，WRAP_CONTENT是-2?

public class TopFragment extends BaseFragment {
private List<String> datas;
@Override
public View createSuccessView() {
ScrollView scrollView=new ScrollView(UiUtils.getContext());
scrollView.setBackgroundResource(R.drawable.grid_item_bg_normal);
LinearLayout layout=new LinearLayout(UiUtils.getContext());
int padding=UiUtils.dip2px(13);
layout.setPadding(padding, padding, padding, padding);
layout.setOrientation(LinearLayout.VERTICAL);// 設置線性布局的方向
int backColor = 0xffcecece;
Drawable pressedDrawable=DrawableUtils.createShape(backColor);// 按下顯示的圖片
for(int i=0;i<datas.size();i++){
TextView textView=new TextView(UiUtils.getContext());
final String str=datas.get(i);
textView.setText(str);
Random random=new Random(); //創建隨機
int red = random.nextInt(200)+22;
int green = random.nextInt(200)+22;
int blue = random.nextInt(200)+22;//有可能都是0或255成白色或者黑色了
int color=Color.rgb(red, green, blue);//范圍 0-255
GradientDrawable createShape = DrawableUtils.createShape(color); // 默認顯示的圖片
StateListDrawable createSelectorDrawable = DrawableUtils.createSelectorDrawable(pressedDrawable, createShape);// 創建狀態選擇器
textView.setBackgroundDrawable(createSelectorDrawable);
textView.setTextColor(Color.WHITE);
//textView.setTextSize(UiUtils.dip2px(14));
int textPaddingV = UiUtils.dip2px(4);
int textPaddingH = UiUtils.dip2px(7);
textView.setPadding(textPaddingH, textPaddingV, textPaddingH, textPaddingV); //設置padding
textView.setClickable(true);//設置textView可以被點擊
textView.setOnClickListener(new OnClickListener() { // 設置點擊事件
@Override
public void onClick(View v) {
Toast.makeText(UiUtils.getContext(), str, 0).show();
}
});
layout.addView(textView,new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, -2));// -2 包裹內容
}
scrollView.addView(layout);
return scrollView;
}
@Override
protected LoadResult load() {
TopProtocol protocol=new TopProtocol();
datas = protocol.load(0);
return checkData(datas);
}
}

到目前為止實現的效果是這樣的，將LinearLayout使用一個自定義控件

Flowlayout?

原理

public class Flowlayout extends ViewGroup {
private int horizontolSpacing=UiUtils.dip2px(13);
private int verticalSpacing=UiUtils.dip2px(13);
public Flowlayout(Context context) {
super(context);
}
public Flowlayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
private Line currentline;// 當前的行
private int useWidth=0;// 當前行使用的寬度
private List<Line> mLines=new ArrayList<Flowlayout.Line>();
private int width;
public Flowlayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
// 測量當前控件Flowlayout
// 父類是有義務測量每個孩子的
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// TODO Auto-generated method stub
// MeasureSpec.EXACTLY;
// MeasureSpec.AT_MOST;
// MeasureSpec.UNSPECIFIED;
mLines.clear();
currentline=null;
useWidth=0;
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec); // 獲取當前父容器(Flowlayout)的模式
width = MeasureSpec.getSize(widthMeasureSpec)-getPaddingLeft()-getPaddingRight();
int height = MeasureSpec.getSize(heightMeasureSpec)-getPaddingBottom()-getPaddingTop(); // 獲取到寬和高
int childeWidthMode;
int childeHeightMode;
// 為了測量每個孩子需要指定每個孩子測量規則
childeWidthMode=(widthMode==MeasureSpec.EXACTLY)?MeasureSpec.AT_MOST:widthMode;
childeHeightMode=heightMode==MeasureSpec.EXACTLY?MeasureSpec.AT_MOST:heightMode;
int childWidthMeasureSpec=MeasureSpec.makeMeasureSpec(childeWidthMode, width);
int childHeightMeasureSpec=MeasureSpec.makeMeasureSpec(childeHeightMode, height);
currentline=new Line();// 創建了第一行
for(int i=0;i<getChildCount();i++) {
View child=getChildAt(i);
System.out.println("孩子的數量:"+getChildCount());
// 測量每個孩子
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
int measuredWidth = child.getMeasuredWidth();
useWidth+=measuredWidth;// 讓當前行加上使用的長度
if(useWidth<=width){
currentline.addChild(child);//這時候證明當前的孩子是可以放進當前的行里,放進去
useWidth+=horizontolSpacing;
if(useWidth>width){
//換行
newLine();
}
}else{
//換行
if(currentline.getChildCount()<1){
currentline.addChild(child); // 保證當前行里面最少有一個孩子
}
newLine();
}
}
if(!mLines.contains(currentline)){
mLines.add(currentline);// 添加最后一行
}
int totalheight=0;
for(Line line:mLines){
totalheight+=line.getHeight();
}
totalheight+=verticalSpacing*(mLines.size()-1)+getPaddingTop()+getPaddingBottom();
System.out.println(totalheight);
setMeasuredDimension(width+getPaddingLeft()+getPaddingRight(),resolveSize(totalheight, heightMeasureSpec));
}
private void newLine() {
mLines.add(currentline);// 記錄之前的行
currentline=new Line(); // 創建新的一行
useWidth=0;
}
private class Line{
int height=0; //當前行的高度
int lineWidth=0;
private List<View> children=new ArrayList<View>();
/**
* 添加一個孩子
* @param child
*/
public void addChild(View child) {
children.add(child);
if(child.getMeasuredHeight()>height){
height=child.getMeasuredHeight();
}
lineWidth+=child.getMeasuredWidth();
}
public int getHeight() {
return height;
}
/**
* 返回孩子的數量
* @return
*/
public int getChildCount() {
return children.size();
}
public void layout(int l, int t) {
lineWidth+=horizontolSpacing*(children.size()-1);
int surplusChild=0;
int surplus=width-lineWidth;
if(surplus>0){
surplusChild=surplus/children.size();
}
for(int i=0;i<children.size();i++){
View child=children.get(i);
// getMeasuredWidth() 控件實際的大小
// getWidth() 控件顯示的大小
child.layout(l, t, l+child.getMeasuredWidth()+surplusChild, t+child.getMeasuredHeight());
l+=child.getMeasuredWidth()+surplusChild;
l+=horizontolSpacing;
}
}
}
// 分配每個孩子的位置
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
l+=getPaddingLeft();
t+=getPaddingTop();
for(int i=0;i<mLines.size();i++){
Line line=mLines.get(i);
line.layout(l,t); //交給每一行去分配
t+=line.getHeight()+verticalSpacing;
}
}
}