格式属性值“android:drawable”无效
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/3487247/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Format attribute value "android:drawable" not valid
提问by Tiago Costa
I'm trying to create custom attributes to my button but I dont know which format I must use to images in attributes declaration...
我正在尝试为我的按钮创建自定义属性，但我不知道我必须对属性声明中的图像使用哪种格式...
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="TCButton">
<attr name="Text" format="string"/>
<attr name="BackgroundImage" format="android:drawable" />
</declare-styleable>
</resources>
Error is in the format="android:drawable"...
错误是格式="android:drawable"...
回答by JOG
You can use format="integer", the resource idof the drawable, and AttributeSet.getDrawable(...).
您可以使用format="integer"、drawable的资源 ID和AttributeSet.getDrawable(...)。
Here is an example.
这是一个例子。
Declare the attribute as integer in res/values/attrs.xml:
在 res/values/attrs.xml 中将属性声明为整数：
<resources>
<declare-styleable name="MyLayout">
<attr name="icon" format="integer" />
</declare-styleable>
</resources>
Set the attribute to a drawable id in your layout:
在布局中将该属性设置为可绘制的 id：
<se.jog.MyLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
myapp:icon="@drawable/myImage"
/>
Get the drawable from the attribute in your custom widget component class:
从自定义小部件组件类中的属性获取可绘制对象：
ImageView myIcon;
//...
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.MyLayout);
Drawable drawable = a.getDrawable(R.styleable.MyLayout_icon);
if (drawable != null)
myIcon.setBackgroundDrawable(drawable);
To see all options possible check the android src here
要查看所有可能的选项，请在此处查看android src
回答by Ionut Negru
I think it will be better to use it as a simple reference:
我认为将其用作简单参考会更好：
<declare-styleable name="TCButton">
<attr name="customText" format="string"/>
<attr name="backgroundImage" format="reference" />
</declare-styleable>
And set it in your xml like this:
并将其设置在您的 xml 中，如下所示：
<your.package.name.TCButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
custom:customText="Some custom text"
custom:backgroundImage="@drawable/myImage"
/>
And in your class set the attributes like this:
并在您的班级中设置如下属性：
public TCButton(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MembershipItemView, 0, 0);
String customText;
Drawable backgroundImage;
try {
customText = a.getString(R.styleable.TCButton_customText);
backgroundImage = a.getDrawable(R.styleable.TCButton_backgroundImage);
} finally {
a.recycle();
}
if(!TextUtils.isEmpty(customText)) {
((TextView)findViewById(R.id.yourTextView)).setText(customText);
}
if(null != backgroundImage) {
((ImageView)findViewById(R.id.yourImageView)).setBackgroundDrawable(backgroundImage);
}
}
PS: Don't forget to add this line for the root element of the layout you are using your custom view in
PS：不要忘记为您使用自定义视图的布局的根元素添加这一行
xmlns:custom="http://schemas.android.com/apk/res-auto"
If you don't set this, you won't be able to access your custom attributes.
如果您不设置此项，您将无法访问您的自定义属性。
回答by CoXier
From AOSP code, I found how google engineers declare ImageView#srcattr.
从 AOSP 代码中，我发现了 google 工程师如何声明ImageView#srcattr。
<declare-styleable name="ImageView">
<attr name="src" format="reference|color" />
<attr name="scaleType">
<enum name="matrix" value="0" />
<enum name="fitXY" value="1" />
<enum name="fitStart" value="2" />
<enum name="fitCenter" value="3" />
<enum name="fitEnd" value="4" />
<enum name="center" value="5" />
<enum name="centerCrop" value="6" />
<enum name="centerInside" value="7" />
</attr>
<attr name="adjustViewBounds" format="boolean" />
<attr name="maxWidth" format="dimension" />
<attr name="maxHeight" format="dimension" />
<attr name="tint" format="color" />
<attr name="baselineAlignBottom" format="boolean" />
<attr name="cropToPadding" format="boolean" />
<attr name="baseline" format="dimension" />
<attr name="drawableAlpha" format="integer" />
<attr name="tintMode" />
</declare-styleable>
Above code is a sample and it can cover most case in our development.
上面的代码是一个示例，它可以覆盖我们开发中的大多数情况。
