我使用自定义布局来显示不同数量的按钮并拦截他们的点击次数。以下是自定义布局的源代码：
import android.content.Context;
import android.content.res.TypedArray;
import android.database.DataSetObserver;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.AdapterView;
public class FlowLayout extends AdapterView<Adapter> {
public static final int HORIZONTAL = 0;
public static final int VERTICAL = 1;
private static final int INVALID_INDEX = -1;
private static final int TOUCH_STATE_RESTING = 0;
private static final int TOUCH_STATE_CLICK = 1;
private int mTouchState = TOUCH_STATE_RESTING;
private Rect mRect;
private Runnable mLongPressRunnable;
private int mTouchStartX;
private int mTouchStartY;
private int horizontalSpacing = 0;
private int verticalSpacing = 0;
private int orientation = 0;
private boolean debugDraw = false;
private Adapter mAdapter;
private final AdapterObserver mObserver = new AdapterObserver();
public FlowLayout(Context context) {
super(context);
this.readStyleParameters(context, null);
}
public FlowLayout(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
this.readStyleParameters(context, attributeSet);
}
public FlowLayout(Context context, AttributeSet attributeSet, int defStyle) {
super(context, attributeSet, defStyle);
this.readStyleParameters(context, attributeSet);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int sizeWidth = MeasureSpec.getSize(widthMeasureSpec) - this.getPaddingRight() - this.getPaddingLeft();
int sizeHeight = MeasureSpec.getSize(heightMeasureSpec) - this.getPaddingRight() - this.getPaddingLeft();
int modeWidth = MeasureSpec.getMode(widthMeasureSpec);
int modeHeight = MeasureSpec.getMode(heightMeasureSpec);
int size;
int mode;
if (orientation == HORIZONTAL) {
size = sizeWidth;
mode = modeWidth;
} else {
size = sizeHeight;
mode = modeHeight;
}
int lineThicknessWithSpacing = 0;
int lineThickness = 0;
int lineLengthWithSpacing = 0;
int lineLength;
int prevLinePosition = 0;
int controlMaxLength = 0;
int controlMaxThickness = 0;
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() == GONE) {
continue;
}
child.measure(
MeasureSpec.makeMeasureSpec(sizeWidth, modeWidth == MeasureSpec.EXACTLY ? MeasureSpec.AT_MOST : modeWidth),
MeasureSpec.makeMeasureSpec(sizeHeight, modeHeight == MeasureSpec.EXACTLY ? MeasureSpec.AT_MOST : modeHeight)
);
LayoutParams lp = (LayoutParams) child.getLayoutParams();
int hSpacing = this.getHorizontalSpacing(lp);
int vSpacing = this.getVerticalSpacing(lp);
int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();
int childLength;
int childThickness;
int spacingLength;
int spacingThickness;
if (orientation == HORIZONTAL) {
childLength = childWidth;
childThickness = childHeight;
spacingLength = hSpacing;
spacingThickness = vSpacing;
} else {
childLength = childHeight;
childThickness = childWidth;
spacingLength = vSpacing;
spacingThickness = hSpacing;
}
lineLength = lineLengthWithSpacing + childLength;
lineLengthWithSpacing = lineLength + spacingLength;
boolean newLine = lp.newLine || (mode != MeasureSpec.UNSPECIFIED && lineLength > size);
if (newLine) {
prevLinePosition = prevLinePosition + lineThicknessWithSpacing;
lineThickness = childThickness;
lineLength = childLength;
lineThicknessWithSpacing = childThickness + spacingThickness;
lineLengthWithSpacing = lineLength + spacingLength;
}
lineThicknessWithSpacing = Math.max(lineThicknessWithSpacing, childThickness + spacingThickness);
lineThickness = Math.max(lineThickness, childThickness);
int posX;
int posY;
if (orientation == HORIZONTAL) {
posX = getPaddingLeft() + lineLength - childLength;
posY = getPaddingTop() + prevLinePosition;
} else {
posX = getPaddingLeft() + prevLinePosition;
posY = getPaddingTop() + lineLength - childHeight;
}
lp.setPosition(posX, posY);
controlMaxLength = Math.max(controlMaxLength, lineLength);
controlMaxThickness = prevLinePosition + lineThickness;
}
if (orientation == HORIZONTAL) {
this.setMeasuredDimension(resolveSize(controlMaxLength, widthMeasureSpec), resolveSize(controlMaxThickness, heightMeasureSpec));
} else {
this.setMeasuredDimension(resolveSize(controlMaxThickness, widthMeasureSpec), resolveSize(controlMaxLength, heightMeasureSpec));
}
}
private int getVerticalSpacing(LayoutParams lp) {
int vSpacing;
if (lp.verticalSpacingSpecified()) {
vSpacing = lp.verticalSpacing;
} else {
vSpacing = this.verticalSpacing;
}
return vSpacing;
}
private int getHorizontalSpacing(LayoutParams lp) {
int hSpacing;
if (lp.horizontalSpacingSpecified()) {
hSpacing = lp.horizontalSpacing;
} else {
hSpacing = this.horizontalSpacing;
}
return hSpacing;
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int count = getChildCount();
for (int i = 0; i < count; i++) {
View child = getChildAt(i);
LayoutParams lp = (LayoutParams) child.getLayoutParams();
child.layout(lp.x, lp.y, lp.x + child.getMeasuredWidth(), lp.y + child.getMeasuredHeight());
}
}
@Override
protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
boolean more = super.drawChild(canvas, child, drawingTime);
this.drawDebugInfo(canvas, child);
return more;
}
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof LayoutParams;
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attributeSet) {
return new LayoutParams(getContext(), attributeSet);
}
@Override
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}
private void readStyleParameters(Context context, AttributeSet attributeSet) {
TypedArray a = context.obtainStyledAttributes(attributeSet, R.styleable.FlowLayout);
try {
horizontalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_horizontalSpacing, 0);
verticalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_verticalSpacing, 0);
orientation = a.getInteger(R.styleable.FlowLayout_orientation, HORIZONTAL);
debugDraw = a.getBoolean(R.styleable.FlowLayout_debugDraw, false);
} finally {
a.recycle();
}
}
private void drawDebugInfo(Canvas canvas, View child) {
if (!debugDraw) {
return;
}
Paint childPaint = this.createPaint(0xffffff00);
Paint layoutPaint = this.createPaint(0xff00ff00);
Paint newLinePaint = this.createPaint(0xffff0000);
LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.horizontalSpacing > 0) {
float x = child.getRight();
float y = child.getTop() + child.getHeight() / 2.0f;
canvas.drawLine(x, y, x + lp.horizontalSpacing, y, childPaint);
canvas.drawLine(x + lp.horizontalSpacing - 4.0f, y - 4.0f, x + lp.horizontalSpacing, y, childPaint);
canvas.drawLine(x + lp.horizontalSpacing - 4.0f, y + 4.0f, x + lp.horizontalSpacing, y, childPaint);
} else if (this.horizontalSpacing > 0) {
float x = child.getRight();
float y = child.getTop() + child.getHeight() / 2.0f;
canvas.drawLine(x, y, x + this.horizontalSpacing, y, layoutPaint);
canvas.drawLine(x + this.horizontalSpacing - 4.0f, y - 4.0f, x + this.horizontalSpacing, y, layoutPaint);
canvas.drawLine(x + this.horizontalSpacing - 4.0f, y + 4.0f, x + this.horizontalSpacing, y, layoutPaint);
}
if (lp.verticalSpacing > 0) {
float x = child.getLeft() + child.getWidth() / 2.0f;
float y = child.getBottom();
canvas.drawLine(x, y, x, y + lp.verticalSpacing, childPaint);
canvas.drawLine(x - 4.0f, y + lp.verticalSpacing - 4.0f, x, y + lp.verticalSpacing, childPaint);
canvas.drawLine(x + 4.0f, y + lp.verticalSpacing - 4.0f, x, y + lp.verticalSpacing, childPaint);
} else if (this.verticalSpacing > 0) {
float x = child.getLeft() + child.getWidth() / 2.0f;
float y = child.getBottom();
canvas.drawLine(x, y, x, y + this.verticalSpacing, layoutPaint);
canvas.drawLine(x - 4.0f, y + this.verticalSpacing - 4.0f, x, y + this.verticalSpacing, layoutPaint);
canvas.drawLine(x + 4.0f, y + this.verticalSpacing - 4.0f, x, y + this.verticalSpacing, layoutPaint);
}
if (lp.newLine) {
if (orientation == HORIZONTAL) {
float x = child.getLeft();
float y = child.getTop() + child.getHeight() / 2.0f;
canvas.drawLine(x, y - 6.0f, x, y + 6.0f, newLinePaint);
} else {
float x = child.getLeft() + child.getWidth() / 2.0f;
float y = child.getTop();
canvas.drawLine(x - 6.0f, y, x + 6.0f, y, newLinePaint);
}
}
}
private Paint createPaint(int color) {
Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(color);
paint.setStrokeWidth(2.0f);
return paint;
}
public static class LayoutParams extends ViewGroup.LayoutParams {
private static int NO_SPACING = -1;
private int x;
private int y;
private int horizontalSpacing = NO_SPACING;
private int verticalSpacing = NO_SPACING;
private boolean newLine = false;
public LayoutParams(Context context, AttributeSet attributeSet) {
super(context, attributeSet);
this.readStyleParameters(context, attributeSet);
}
public LayoutParams(int width, int height) {
super(width, height);
}
public LayoutParams(ViewGroup.LayoutParams layoutParams) {
super(layoutParams);
}
public boolean horizontalSpacingSpecified() {
return horizontalSpacing != NO_SPACING;
}
public boolean verticalSpacingSpecified() {
return verticalSpacing != NO_SPACING;
}
public void setHorizontalSpacing(int hs) {
horizontalSpacing = hs;
}
public void setVerticalSpacing(int vs) {
verticalSpacing = vs;
}
public void setPosition(int x, int y) {
this.x = x;
this.y = y;
}
private void readStyleParameters(Context context, AttributeSet attributeSet) {
TypedArray a = context.obtainStyledAttributes(attributeSet, R.styleable.FlowLayout_LayoutParams);
try {
horizontalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_LayoutParams_layout_horizontalSpacing, NO_SPACING);
verticalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_LayoutParams_layout_verticalSpacing, NO_SPACING);
newLine = a.getBoolean(R.styleable.FlowLayout_LayoutParams_layout_newLine, false);
} finally {
a.recycle();
}
}
}
@Override
public Adapter getAdapter() {
return mAdapter;
}
@Override
public View getSelectedView() {
throw new UnsupportedOperationException("Not supported");
}
@Override
public void setAdapter(Adapter adapter) {
if (mAdapter != null) {
mAdapter.unregisterDataSetObserver(mObserver);
}
mAdapter = adapter;
mAdapter.registerDataSetObserver(mObserver);
refresh();
}
public void refresh() {
removeAllViewsInLayout();
for (int i = 0; i < mAdapter.getCount(); i++) {
final View view = mAdapter.getView(i, null, this);
ViewGroup.LayoutParams params = view.getLayoutParams();
if (params == null) {
params = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
addViewInLayout(view, i, params, true);
}
postInvalidate();
requestLayout();
}
public class AdapterObserver extends DataSetObserver {
@Override
public void onChanged() {
refresh();
}
@Override
public void onInvalidated() {
}
}
@Override
public void setSelection(int position) {
throw new UnsupportedOperationException("Not supported");
}
// Touch detection
@Override
public boolean onTouchEvent(MotionEvent event) {
if (getChildCount() == 0) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startTouch(event);
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_CLICK) {
clickChildAt((int)event.getX(), (int)event.getY());
}
endTouch();
break;
default:
endTouch();
break;
}
return true;
}
/**
* Sets and initializes all things that need to when we start a touch
* gesture.
*
* @param event The down event
*/
private void startTouch(final MotionEvent event) {
mTouchStartX = (int)event.getX();
mTouchStartY = (int)event.getY();
startLongPressCheck();
mTouchState = TOUCH_STATE_CLICK;
}
private void startLongPressCheck() {
if (mLongPressRunnable == null) {
mLongPressRunnable = new Runnable() {
public void run() {
if (mTouchState == TOUCH_STATE_CLICK) {
final int index = getContainingChildIndex(mTouchStartX, mTouchStartY);
if (index != INVALID_INDEX) { longClickChild(index); mTouchState = TOUCH_STATE_RESTING; }
}
}
};
}
postDelayed(mLongPressRunnable, 300); //ViewConfiguration.getLongPressTimeout()
}
private void longClickChild(final int index) {
final View itemView = getChildAt(index);
final int position = index;
final long id = mAdapter.getItemId(position);
final OnItemLongClickListener listener = getOnItemLongClickListener();
if (listener != null) { listener.onItemLongClick(this, itemView, position, id); }
}
private int getContainingChildIndex(final int x, final int y) {
if (mRect == null) { mRect = new Rect(); }
for (int index = 0; index < getChildCount(); index++) {
getChildAt(index).getHitRect(mRect);
if (mRect.contains(x, y)) { return index; }
}
return INVALID_INDEX;
}
private void endTouch() {
removeCallbacks(mLongPressRunnable);
mTouchState = TOUCH_STATE_RESTING;
}
private void clickChildAt(final int x, final int y) {
final int index = getContainingChildIndex(x, y);
if (index != INVALID_INDEX) {
final View itemView = getChildAt(index);
final int position = index;
final long id = mAdapter.getItemId(position);
performItemClick(itemView, position, id);
}
}
}
此代码适用于我的测试设备，该设备是带有Android 4.1.2的Google Nexus S，这意味着这些按钮是可点击的。然而，我得到的报告显示按键在其他设备上没有响应，例如安卓版本2.3.3的Android卡西欧C771和安卓版4.0.4的威瑞森LG VS840。
您能否告诉我可能导致这种差异的原因以及如何解决？
谢谢
答案 0 :(得分：1)
需要注意的事项：
为适配器创建的View必须为点击和触摸操作启用。创建它们之后：
View.setEnabled(true);
当您创建AdapterView和BaseApapter时，如果您想要处理长时间点击，请记住同时setOnItemClickListener和setOnItemLongClickListener
在endTouch例程中，您需要将mLongPressRunnable设置为null，以便为下一次触摸创建它（或者null签入startLongPressCheck并以另一种方式处理concurency问题。）
startLongPressCheck中创建的可运行需要在完成时调用endTouch以重置所有内容，没有任何待处理状态，在长时间后显示。
在onTouchEvent switch声明中，不要调用endTouch例程非常重要，因为这意味着移动事件可能会停止点击。
有一项建议（请参阅Android onClick method doesn't work on a custom view），如果您未在super.onTouchEvent(event)中致电onTouchEvent，则可能会导致问题。这看起来像是：
@Override
public boolean onTouchEvent(MotionEvent event) {
if (getChildCount() == 0) {
return super.onTouchEvent(event);
}
boolean handled = false;
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startTouch(event);
handled = true;
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_CLICK) {
clickChildAt((int)event.getX(), (int)event.getY());
handled = true;
}
endTouch();
break;
default:
// Do not do anything dramatic here because the system
// may send different (eg. motion) information here which
// may lead to you losing valid clicks if you simply cancel
// the click in process.
break;
}
if (handled == false) handled = super.onTouchEvent(event);
return handled;
}