我创建了一个具有自定义属性的按钮(实际上是一个线性布局，它有一个ImageView和一个TextView，功能类似于按钮(。问题是，当我尝试在 xml 布局定义中实现此自定义按钮以进行活动时，它不会显示。我该如何解决这个问题？
FacebookCustomButton
package com.android.neuron.custombuttons;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.Gravity;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class FacebookCustomButton extends LinearLayout {
private Context context;
private ImageView iconView;
private TextView textView;
private String iconPath;
private Drawable iconResource;
private String textSource;
private int iconWidth;
private int iconHeight;
private int iconGravity = 0x11; //Gravity.CENTER
private int iconMarginStart;
private int iconMarginEnd;
private int iconMarginTop;
private int iconMarginBottom;
private int textGravity = 0x11; //center
private int textSize;
private int textColor;
public FacebookCustomButton(Context context) {
super(context);
this.context = context;
initializeButton();
}
public FacebookCustomButton(Context context, AttributeSet attrs) {
super(context, attrs);
initAttrs(context, attrs);
initializeButton();
}
public FacebookCustomButton(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initAttrs(context, attrs);
initializeButton();
}
void initAttrs(Context context, AttributeSet attrs) {
if(attrs!=null) {
TypedArray attributeArray = context.obtainStyledAttributes(attrs, R.styleable.FacebookCustomButton);
iconResource = attributeArray.getDrawable(R.styleable.FacebookCustomButton_icon_resource);
String text = attributeArray.getString(R.styleable.FacebookCustomButton_text_source);
if(text==null) { //no fb textView attribuute
text = attributeArray.getString(R.styleable.FacebookCustomButton_android_text);
}
textSource = text;
iconWidth = (int) attributeArray.getDimension(R.styleable.FacebookCustomButton_icon_width, Constants.fbButton_icon_default_width);
iconHeight = (int) attributeArray.getDimension(R.styleable.FacebookCustomButton_icon_height, Constants.fbButton_icon_default_height);
iconGravity = attributeArray.getInt(R.styleable.FacebookCustomButton_icon_gravity, Constants.fbButton_icon_default_gravity);
iconMarginStart = attributeArray.getInt(R.styleable.FacebookCustomButton_icon_marginStart, Constants.fbButton_icon_default_margin_start);
iconMarginEnd = attributeArray.getInt(R.styleable.FacebookCustomButton_icon_marginEnd, Constants.fbButton_icon_default_margin_end);
iconMarginTop = attributeArray.getInt(R.styleable.FacebookCustomButton_icon_marginTop, Constants.fbButton_icon_default_margin_top);
iconMarginBottom = attributeArray.getInt(R.styleable.FacebookCustomButton_icon_marginBottom, Constants.fbButton_icon_default_margin_bottom);
textGravity = attributeArray.getInt(R.styleable.FacebookCustomButton_text_gravity, Constants.fbButton_icon_default_gravity);
textSize = (int) attributeArray.getDimension(R.styleable.FacebookCustomButton_text_size, Constants.fbButton_text_size);
String textFontFamily = attributeArray.getString(R.styleable.FacebookCustomButton_text_font);
Typeface font = Typeface.createFromAsset(context.getAssets(), textFontFamily);
textView.setTypeface(font);
textColor = attributeArray.getColor(R.styleable.FacebookCustomButton_text_color, getResources().getColor(R.color.fb_defaultColor));
}
}
/**
* Initalizes the button:
* - the container (linear layout)
* - the iconView view
* - the textView view
*/
private void initializeButton() {
initializeButtonContainer();
iconView = initializeIconView();
textView = initializeTextView();
}
private void initializeButtonContainer() {
this.setOrientation(LinearLayout.HORIZONTAL);
if(this.getLayoutParams() == null) {
LayoutParams containerParams = new LayoutParams(LayoutParams.WRAP_CONTENT, Constants.fbButton_default_height);
containerParams.setMargins(Constants.fbButton_default_margin_start,
Constants.fbButton_default_margin_top,
Constants.fbButton_default_margin_end,
Constants.fbButton_default_margin_bottom);
this.setLayoutParams(containerParams);
}
this.setGravity(Gravity.CENTER);
this.setBackground(context.getDrawable(R.drawable.background_facebook_sign_up_button));
}
private TextView initializeTextView() {
if(textSource == null) {
textSource = context.getResources().getString(R.string.fbButton_default_text_source);
}
TextView textView = new TextView(context);
textView.setText(textSource);
textView.setGravity(textGravity);
textView.setTextColor(textColor);
textView.setTextSize(textSize);
textView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
/*
Typeface font = Typeface.createFromAsset(context.getAssets(), Constants.default_font_path);
textView.setTypeface(font);
*/
return textView;
}
private ImageView initializeIconView() {
if(iconResource != null) {
ImageView iconView = new ImageView(context);
iconView.setImageDrawable(iconResource);
LayoutParams iconViewParams = new LayoutParams(iconWidth, iconHeight);
iconViewParams.gravity = iconGravity;
iconViewParams.setMarginStart(iconMarginStart);
iconViewParams.setMarginEnd(iconMarginEnd);
iconView.setLayoutParams(iconViewParams);
return iconView;
} else {
System.out.println("[Neuron.custombuttons.FCB]: Error getting iconView resource! Reutnring null.");
return null;
}
}
}
吸引.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="FacebookCustomButton">
<!-- Default Android attrs -->
<attr name="android:enabled" />
<attr name="android:text" />
<attr name="android:textSize" />
<attr name="android:textAllCaps" />
<attr name="android:textStyle" />
<attr name="android:fontFamily" />
<attr name="icon_width" format="dimension"/>
<attr name="icon_height" format="dimension"/>
<attr name="icon_gravity" format="enum">
<enum name="top" value="0x30" />
<enum name="bottom" value="0x50" />
<enum name="left" value="0x03" />
<enum name="right" value="0x05" />
<enum name="center_vertical" value="0x10" />
<enum name="fill_vertical" value="0x70" />
<enum name="center_horizontal" value="0x01" />
<enum name="fill_horizontal" value="0x07" />
<enum name="center" value="0x11" />
<enum name="fill" value="0x77" />
<enum name="clip_vertical" value="0x80" />
<enum name="clip_horizontal" value="0x08" />
<enum name="start" value="0x00800003" />
<enum name="end" value="0x00800005" />
</attr>
<attr name="icon_resource" format="integer"/>
<attr name="icon_marginStart" format="dimension"/>
<attr name="icon_marginEnd" format="dimension"/>
<attr name="icon_marginTop" format="dimension"/>
<attr name="icon_marginBottom" format="dimension"/>
<attr name="text_source" format="string"/>
<attr name="text_gravity" format="enum">
<enum name="top" value="0x30" />
<enum name="bottom" value="0x50" />
<enum name="left" value="0x03" />
<enum name="right" value="0x05" />
<enum name="center_vertical" value="0x10" />
<enum name="fill_vertical" value="0x70" />
<enum name="center_horizontal" value="0x01" />
<enum name="fill_horizontal" value="0x07" />
<enum name="center" value="0x11" />
<enum name="fill" value="0x77" />
<enum name="clip_vertical" value="0x80" />
<enum name="clip_horizontal" value="0x08" />
<enum name="start" value="0x00800003" />
<enum name="end" value="0x00800005" />
</attr>
<attr name="text_size" format="dimension"/>
<attr name="text_font" format="string"/>
<attr name="text_color" format="color"/>
</declare-styleable>
</resources>
注册活动中的实现：
<com.android.neuron.custombuttons.FacebookCustomButton
android:layout_width="match_parent"
android:layout_height="40dp"
app:text_source="@string/facebook_signup_button_text"
app:text_size="14sp"
app:text_color="@color/white"
app:text_font="@font/roboto_medium"
app:text_gravity="center"
app:icon_resource="@drawable/ic_fb_white"
app:icon_gravity="center"
app:icon_height="24dp"
app:icon_width="24dp"
app:icon_marginBottom="0dp"
app:icon_marginEnd="42dp"
app:icon_marginStart="8dp"
app:icon_marginTop="0dp" />
您只是在加载LinearLayout。您没有将创建的子视图添加到父LinearLayout中。试试这个
private void initializeButton() {
initializeButtonContainer();
iconView = initializeIconView();
textView = initializeTextView();
this.addView(iconView);
this.addView(textView);
}