1
我创建了一个自定义视图（ArrowContainer）来环绕其他元素，给它们一个箭头形状的背景。但是，当包含在相对布局中时，我的视图与包含在线性布局中时的显示方式有所不同。在线性和相对布局中显示不同的自定义Android视图
这里是问题，顶部的ArrowContainer包含在LinearLayout中并且行为正确，底部的ArrowContainer包含在RelativeLayout中并且行为不正确。
有没有人见过这样的事情之前？我已经插入ArrowContainer.java调试代码表明，从问题产生的RelativeLayout两次测量的观点，但我不知道为什么，这将导致一个问题...
下面是代码：
ArrowContainer的.java
package com.example.arrowcontainertest;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Path;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
public class ArrowContainer extends ViewGroup {
private static final int ARROW_LEFT = 0;
private static final int ARROW_RIGHT = 1;
private static final int ARROW_BOTH = 2;
private static final int DEFAULT_COLOUR = 0xFFFF0000;
private static final int HORIZONTAL_PADDING = 150;
private Path path;
private Paint paint;
private int arrowSide = ARROW_RIGHT;
private int colour = DEFAULT_COLOUR;
private int downColour;
private Paint downPaint;
private Boolean isButton = false;
private View child;
public ArrowContainer(Context context) {
super(context);
init();
}
public ArrowContainer(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.ArrowContainer, 0, 0);
try {
arrowSide = a.getInteger(R.styleable.ArrowContainer_arrowSide, ARROW_RIGHT);
colour = a.getColor(R.styleable.ArrowContainer_colour, DEFAULT_COLOUR);
isButton = a.getBoolean(R.styleable.ArrowContainer_isButton, false);
} finally {
a.recycle();
}
init();
}
public ArrowContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.ArrowContainer, 0, 0);
try {
arrowSide = a.getInteger(R.styleable.ArrowContainer_arrowSide, ARROW_RIGHT);
colour = a.getColor(R.styleable.ArrowContainer_colour, DEFAULT_COLOUR);
isButton = a.getBoolean(R.styleable.ArrowContainer_isButton, false);
} finally {
a.recycle();
}
init();
}
private void init() {
paint = new Paint();
paint.setColor(colour);
paint.setStyle(Style.FILL);
setWillNotDraw(false);
if (isButton) {
setFocusable(true);
setClickable(true);
downColour = 0xFF00FF00;
downPaint = new Paint();
downPaint.setColor(downColour);
downPaint.setStyle(Style.FILL);
}
}
@Override
protected void onFinishInflate() {
// Must have exactly 1 child
assert getChildCount()==1;
if (getChildCount() == 1) {
child = getChildAt(0);
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Debug
Log.e("DEBUG", "Type:" + getParent().getClass());
Log.e("DEBUG", "Width Mode: " + MeasureSpec.getMode(widthMeasureSpec));
Log.e("DEBUG", "Height Mode: " + MeasureSpec.getMode(heightMeasureSpec));
Log.e("DEBUG", "Width Size: " + MeasureSpec.getSize(widthMeasureSpec));
Log.e("DEBUG", "Height Size: " + MeasureSpec.getSize(heightMeasureSpec));
// Restrict the childs width to at most this components size minus a fixed value (HORIZONTAL_PADDING*numArrows)
int numArrows=0;
switch (arrowSide) {
case ARROW_RIGHT:
numArrows = 1;
break;
case ARROW_LEFT:
numArrows = 1;
break;
case ARROW_BOTH:
numArrows = 2;
break;
}
int widthSpec = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec)-HORIZONTAL_PADDING*numArrows, MeasureSpec.AT_MOST);
int heightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
child.measure(widthSpec, heightSpec);
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();
setMeasuredDimension(width + (int) (numArrows*height/2f), height);
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int width = getMeasuredWidth();
int height = getMeasuredHeight();
int childWidth = child.getMeasuredWidth();
int childHeight = child.getMeasuredHeight();
switch (arrowSide) {
case ARROW_RIGHT:
// Hug left
child.layout(0, height/2 - childHeight/2, width - height/2, height/2 + childHeight/2);
break;
case ARROW_LEFT:
// Hug right
child.layout(height/2, height/2 - childHeight/2, width, height/2 + childHeight/2);
break;
case ARROW_BOTH:
// Center
child.layout(width/2 - childWidth/2, height/2 - childHeight/2, width/2 + childWidth/2, height/2 + childHeight/2);
break;
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
path = new Path();
switch (arrowSide) {
case ARROW_RIGHT:
path.lineTo(0, h);
path.lineTo(w-h/2f, h);
path.lineTo(w, h/2f);
path.lineTo(w-h/2f, 0);
break;
case ARROW_LEFT:
path.moveTo(h/2f, 0);
path.lineTo(0, h/2f);
path.lineTo(h/2f, h);
path.lineTo(w, h);
path.lineTo(w, 0);
break;
case ARROW_BOTH:
path.moveTo(h/2f, 0);
path.lineTo(0, h/2f);
path.lineTo(h/2f, h);
path.lineTo(w-h/2f, h);
path.lineTo(w, h/2f);
path.lineTo(w-h/2f, 0);
break;
}
path.close();
}
@Override
protected void onDraw(Canvas canvas) {
invalidate();
if (isPressed()) {
canvas.drawPath(path, downPaint);
} else {
canvas.drawPath(path, paint);
}
super.onDraw(canvas);
}
}
activity_main.xml中
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context=".MainActivity" xmlns:app="http://schemas.android.com/apk/res/com.example.arrowcontainertest">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.example.arrowcontainertest.ArrowContainer
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:arrowSide="right">
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Play"
android:textSize="50sp"/>
</com.example.arrowcontainertest.ArrowContainer>
</LinearLayout>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.example.arrowcontainertest.ArrowContainer
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:arrowSide="right">
<TextView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Play"
android:textSize="50sp"/>
</com.example.arrowcontainertest.ArrowContainer>
</RelativeLayout>
MainActivity.java
package com.example.arrowcontainertest;
import android.os.Bundle;
import android.app.Activity;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
这是件好事，你已经找到解决办法，但我想说的是，你应该使用父视图，而不是测量值提供的视图尺寸的实际值。我的意思是在'onLayout'中有'l'，'t'，'r'和'b'。如果您查看度量自身，比如说100x100，但您想扩展它以填充父级的宽度，那么如果您使用测量值而不是父级提供的值，则不会得到任何结果。 – nekavally
谢谢，未来会这样做！ – WMycroft