android 自己定义ViewGroup实现可记载并呈现选择的ListView

转载请注明出处：王亟亟的大牛之路

之前也做过一些用TextView之类的记录ListView选项的东西。可是总认为好难看。发现个不错的实现就贴给大家。

项目文件夹



执行效果：



自己定义视图：

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public class FlowLayout extends ViewGroup {

private int mGravity = (isIcs() ? Gravity.START : Gravity.LEFT) | Gravity.TOP;

private final List<List<View>> mLines = new ArrayList<List<View>>();
private final List<Integer> mLineHeights = new ArrayList<Integer>();
private final List<Integer> mLineMargins = new ArrayList<Integer>();

public FlowLayout(Context context) {
this(context, null);
}

public FlowLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}

public FlowLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);

TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.FlowLayout, defStyle, 0);

try {
int index = a.getInt(R.styleable.FlowLayout_android_gravity, -1);
if(index > 0) {
setGravity(index);
}
} finally {
a.recycle();
}

}

/**
* {@inheritDoc}
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);

int sizeWidth = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);

int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
int modeHeight = MeasureSpec.getMode(heightMeasureSpec);

int width = 0;
int height = getPaddingTop() + getPaddingBottom();

int lineWidth = 0;
int lineHeight = 0;

int childCount = getChildCount();

for(int i = 0; i < childCount; i++) {

View child = getChildAt(i);
boolean lastChild = i == childCount - 1;

if(child.getVisibility() == View.GONE) {

if(lastChild) {
width = Math.max(width, lineWidth);
height += lineHeight;
}

continue;
}

measureChildWithMargins(child, widthMeasureSpec, lineWidth, heightMeasureSpec, height);

LayoutParams lp = (LayoutParams) child.getLayoutParams();

int childWidthMode = MeasureSpec.AT_MOST;
int childWidthSize = sizeWidth;

int childHeightMode = MeasureSpec.AT_MOST;
int childHeightSize = sizeHeight;

if(lp.width == LayoutParams.MATCH_PARENT) {
childWidthMode = MeasureSpec.EXACTLY    ;
childWidthSize -= lp.leftMargin + lp.rightMargin;
} else if(lp.width >= 0) {
childWidthMode = MeasureSpec.EXACTLY;
childWidthSize = lp.width;
}

if(lp.height >= 0) {
childHeightMode = MeasureSpec.EXACTLY;
childHeightSize = lp.height;
} else if (modeHeight == MeasureSpec.UNSPECIFIED) {
childHeightMode = MeasureSpec.UNSPECIFIED;
childHeightSize = 0;
}

child.measure(
MeasureSpec.makeMeasureSpec(childWidthSize, childWidthMode),
MeasureSpec.makeMeasureSpec(childHeightSize, childHeightMode)
);

int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;

if(lineWidth + childWidth > sizeWidth) {

width = Math.max(width, lineWidth);
lineWidth = childWidth;

height += lineHeight;
lineHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;

} else {
lineWidth += childWidth;
lineHeight = Math.max(lineHeight, child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin);
}

if(lastChild) {
width = Math.max(width, lineWidth);
height += lineHeight;
}

}

width += getPaddingLeft() + getPaddingRight();

setMeasuredDimension(
(modeWidth == MeasureSpec.EXACTLY) ? sizeWidth : width,
(modeHeight == MeasureSpec.EXACTLY) ? sizeHeight : height);
}

/**
* {@inheritDoc}
*/
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {

mLines.clear();
mLineHeights.clear();
mLineMargins.clear();

int width = getWidth();
int height = getHeight();

int linesSum = getPaddingTop();

int lineWidth = 0;
int lineHeight = 0;
List<View> lineViews = new ArrayList<View>();

float horizontalGravityFactor;
switch ((mGravity & Gravity.HORIZONTAL_GRAVITY_MASK)) {
case Gravity.LEFT:
default:
horizontalGravityFactor = 0;
break;
case Gravity.CENTER_HORIZONTAL:
horizontalGravityFactor = .5f;
break;
case Gravity.RIGHT:
horizontalGravityFactor = 1;
break;
}

for(int i = 0; i < getChildCount(); i++) {

View child = getChildAt(i);

if(child.getVisibility() == View.GONE) {
continue;
}

LayoutParams lp = (LayoutParams) child.getLayoutParams();

int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
int childHeight = child.getMeasuredHeight() + lp.bottomMargin + lp.topMargin;

if(lineWidth + childWidth > width) {
mLineHeights.add(lineHeight);
mLines.add(lineViews);
mLineMargins.add((int) ((width - lineWidth) * horizontalGravityFactor) + getPaddingLeft());

linesSum += lineHeight;

lineHeight = 0;
lineWidth = 0;
lineViews = new ArrayList<View>();
}

lineWidth += childWidth;
lineHeight = Math.max(lineHeight, childHeight);
lineViews.add(child);
}

mLineHeights.add(lineHeight);
mLines.add(lineViews);
mLineMargins.add((int) ((width - lineWidth) * horizontalGravityFactor) + getPaddingLeft());

linesSum += lineHeight;

int verticalGravityMargin = 0;
switch ((mGravity & Gravity.VERTICAL_GRAVITY_MASK)  ) {
case Gravity.TOP:
default:
break;
case Gravity.CENTER_VERTICAL:
verticalGravityMargin = (height - linesSum) / 2;
break;
case Gravity.BOTTOM:
verticalGravityMargin = height - linesSum;
break;
}

int numLines = mLines.size();

int left;
int top = getPaddingTop();

for(int i = 0; i < numLines; i++) {

lineHeight = mLineHeights.get(i);
lineViews = mLines.get(i);
left = mLineMargins.get(i);

int children = lineViews.size();

for(int j = 0; j < children; j++) {

View child = lineViews.get(j);

if(child.getVisibility() == View.GONE) {
continue;
}

LayoutParams lp = (LayoutParams) child.getLayoutParams();

// if height is match_parent we need to remeasure child to line height
if(lp.height == LayoutParams.MATCH_PARENT) {
int childWidthMode = MeasureSpec.AT_MOST;
int childWidthSize = lineWidth;

if(lp.width == LayoutParams.MATCH_PARENT) {
childWidthMode = MeasureSpec.EXACTLY;
} else if(lp.width >= 0) {
childWidthMode = MeasureSpec.EXACTLY;
childWidthSize = lp.width;
}

child.measure(
MeasureSpec.makeMeasureSpec(childWidthSize, childWidthMode),
MeasureSpec.makeMeasureSpec(lineHeight - lp.topMargin - lp.bottomMargin, MeasureSpec.EXACTLY)
);
}

int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();

int gravityMargin = 0;

if(Gravity.isVertical(lp.gravity)) {
switch (lp.gravity) {
case Gravity.TOP:
default:
break;
case Gravity.CENTER_VERTICAL:
case Gravity.CENTER:
gravityMargin = (lineHeight - childHeight - lp.topMargin - lp.bottomMargin) / 2 ;
break;
case Gravity.BOTTOM:
gravityMargin = lineHeight - childHeight - lp.topMargin - lp.bottomMargin;
break;
}
}

child.layout(left + lp.leftMargin,
top + lp.topMargin + gravityMargin + verticalGravityMargin,
left + childWidth + lp.leftMargin,
top + childHeight + lp.topMargin + gravityMargin + verticalGravityMargin);

left += childWidth + lp.leftMargin + lp.rightMargin;

}

top += lineHeight;
}

}

@Override
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}

/**
* {@inheritDoc}
*/
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new LayoutParams(getContext(), attrs);
}

/**
* {@inheritDoc}
*/
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
}

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
public void setGravity(int gravity) {
if(mGravity != gravity) {
if((gravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK) == 0) {
gravity |= isIcs() ? Gravity.START : Gravity.LEFT;
}

if((gravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) {
gravity |= Gravity.TOP;
}

mGravity = gravity;
requestLayout();
}
}

public int getGravity() {
return mGravity;
}

/**
* @return <code>true</code> if device is running ICS or grater version of Android.
*/
private static boolean isIcs() {
return Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH;
}

public static class LayoutParams extends MarginLayoutParams {

public int gravity = -1;

public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);

TypedArray a = c.obtainStyledAttributes(attrs, R.styleable.FlowLayout_Layout);

try {
gravity = a.getInt(R.styleable.FlowLayout_Layout_android_layout_gravity, -1);
} finally {
a.recycle();
}
}

public LayoutParams(int width, int height) {
super(width, height);
}

public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}

}

}

分析：

这部分主要是呈现被选项的实现。伸手党能够无视

对象：

public class Filter_Object {
public String mName ;
public boolean mIsSelected ;
}

分析：填充是否被选，以及listView每一行的显示内容

MainActivity:

public class MainActivity extends AppCompatActivity {
private ListView mListView;
private ArrayList<Filter_Object> mArrFilter;
private ScrollView mScrollViewFilter;
private Filter_Adapter mFilter_Adapter ;
private FlowLayout mFlowLayoutFilter ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {

getWindow().setStatusBarColor(getResources().getColor(R.color.themecolor));
}

mArrFilter = new ArrayList<>();

String[] strArr = getResources().getStringArray(R.array.city);

int lengthOfstrArr = strArr.length;

for (int i = 0; i < lengthOfstrArr; i++) {
Filter_Object filter_object = new Filter_Object();
filter_object.mName = strArr[i];
filter_object.mIsSelected = false;
mArrFilter.add(filter_object);
}

getSupportActionBar().setDisplayShowTitleEnabled(true);
getSupportActionBar().setTitle(getString(R.string.app_name));

mListView = (ListView) findViewById(R.id.listViewFilter);
mScrollViewFilter = (ScrollView)findViewById(R.id.scrollViewFilter);
//放置被选项的布局
mFlowLayoutFilter = (FlowLayout)findViewById(R.id.flowLayout);

mFilter_Adapter = new Filter_Adapter(mArrFilter);
mListView.setAdapter(mFilter_Adapter);
}
public void addFilterTag() {
final ArrayList<Filter_Object> arrFilterSelected = new ArrayList<>();

mFlowLayoutFilter.removeAllViews();

int length = mArrFilter.size();
boolean isSelected = false;
for (int i = 0; i < length; i++) {
Filter_Object fil = mArrFilter.get(i);
if (fil.mIsSelected) {
isSelected = true;
arrFilterSelected.add(fil);
}
}
if (isSelected) {
mScrollViewFilter.setVisibility(View.VISIBLE);
} else {
mScrollViewFilter.setVisibility(View.GONE);
}
int size = arrFilterSelected.size();
LayoutInflater layoutInflater = (LayoutInflater)
this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

for (int i = 0; i < size; i++) {
View view = layoutInflater.inflate(R.layout.filter_tag_edit, null);

TextView tv = (TextView) view.findViewById(R.id.tvTag);
LinearLayout linClose = (LinearLayout) view.findViewById(R.id.linClose);
final Filter_Object filter_object = arrFilterSelected.get(i);
linClose.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//showToast(filter_object.name);

int innerSize = mArrFilter.size();
for (int j = 0; j < innerSize; j++) {
Filter_Object mFilter_Object = mArrFilter.get(j);
if (mFilter_Object.mName.equalsIgnoreCase(filter_object.mName)) {
mFilter_Object.mIsSelected = false;

}
}
addFilterTag();
mFilter_Adapter.updateListView(mArrFilter);
}
});

tv.setText(filter_object.mName);
int color = getResources().getColor(R.color.themecolor);

View newView = view;
newView.setBackgroundColor(color);

FlowLayout.LayoutParams params = new FlowLayout.LayoutParams(FlowLayout.LayoutParams.WRAP_CONTENT, FlowLayout.LayoutParams.WRAP_CONTENT);
params.rightMargin = 10;
params.topMargin = 5;
params.leftMargin = 10;
params.bottomMargin = 5;

newView.setLayoutParams(params);

mFlowLayoutFilter.addView(newView);
}
}

public class Filter_Adapter extends BaseAdapter {
ArrayList<Filter_Object> arrMenu;

public Filter_Adapter(ArrayList<Filter_Object> arrOptions) {
this.arrMenu = arrOptions;
}

public void updateListView(ArrayList<Filter_Object> mArray) {
this.arrMenu = mArray;
notifyDataSetChanged();
}

@Override
public int getCount() {
return this.arrMenu.size();
}

@Override
public Object getItem(int position) {
return null;
}

@Override
public long getItemId(int position) {
return 0;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = getLayoutInflater().inflate(R.layout.filter_list_item, null);
viewHolder = new ViewHolder();
viewHolder.mTtvName = (TextView) convertView.findViewById(R.id.tvName);
viewHolder.mTvSelected = (TextView) convertView.findViewById(R.id.tvSelected);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
final Filter_Object mService_Object = arrMenu.get(position);
viewHolder.mTtvName.setText(mService_Object.mName);

if (mService_Object.mIsSelected) {
viewHolder.mTvSelected.setVisibility(View.VISIBLE);
} else {
viewHolder.mTvSelected.setVisibility(View.INVISIBLE);
}
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {

mService_Object.mIsSelected = !mService_Object.mIsSelected;
mScrollViewFilter.setVisibility(View.VISIBLE);

addFilterTag();
notifyDataSetChanged();
}
});
return convertView;
}

public class ViewHolder {
TextView mTtvName, mTvSelected;

}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
// getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();

//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}

return super.onOptionsItemSelected(item);
}
}

分析：

层次非常分明，从填充本地数据–>转加载ListView–>附加逻辑–>呈现。等流程思路非常清晰，可读性非常强。

详细使用，能够看源代码。一目了然。

源代码地址：http://yunpan.cn/cdbbFUd8rLFmJ 訪问password af07