行为像工具:自定义视图中的文本? [英] Behavior like tools:text in a custom view?

问题描述

我有一个自定义视图，在布局中有两个文本视图.我们称一个key和另一个value.

I have a custom view with two text views in the layout. Let's call one key and the other value.

所以您知道TextView的情况如何?

So you know how TextView has this?

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    tools:text="Preview text shown in the layout editor" />

我想对自定义视图执行类似的操作，例如:

I want to do something similar with my custom view, e.g.:

<com.package.whatever.MyCustomView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:key_preview="Preview text for the key"
    app:value_preview="Preview text for the value" />

MyCustomView的构造函数如下:

public MyCustomView(Context context, AttributeSet attrs) {
    super(context, attrs);

    ((LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE))
            .inflate(R.layout.my_custom_view, this, true);

    key = (TextView) findViewById(R.id.key);
    value = (TextView) findViewById(R.id.value);

    TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.MyCustomView, 0, 0);
    try {
        if (isInEditMode()) {
            key.setText(a.getText(R.styleable.MyCustomView_key_preview));
            value.setText(a.getText(R.styleable.MyCustomView_value_preview));
        }
        key.setText(a.getText(R.styleable.MyCustomView_key));
        value.setText(a.getText(R.styleable.MyCustomView_value));
    } finally {
        a.recycle();
    }
}

和attrs.xml:

<declare-styleable name="MyCustomView">
    <attr name="key" format="string" />
    <attr name="key_preview" format="string" />
    <attr name="value" format="string" />
    <attr name="value_preview" format="string" />
</declare-styleable>

问题是，当我在布局编辑器中查看包含MyCustomView的布局时，isInEditMode()返回false.如果我添加app:key="yay"可以正常工作，但对于app:key_preview="nay :("则什么也没有显示.

The issue is that isInEditMode() is returning false when I view a layout which includes MyCustomView in the layout editor. If I add app:key="yay" it works fine, but for app:key_preview="nay :(" nothing shows up.

有什么作用?

推荐答案

我是丁格，对所有人撒谎. isInEditMode()没有返回false.

I am a dingus and lied to you all. isInEditMode() was not returning false.

咳嗽咳嗽:

    if (isInEditMode()) {
        key.setText(a.getText(R.styleable.MyCustomView_key_preview));
        value.setText(a.getText(R.styleable.MyCustomView_value_preview));
    } else {
        key.setText(a.getText(R.styleable.MyCustomView_key));
        value.setText(a.getText(R.styleable.MyCustomView_value));
    }

原来我实际上将键设置为app:key_preview的值，但是随后又用a.getText(R.styleable.MyCustomView_key)返回的null覆盖了它.

Turns out what I had initially was in fact setting the key to be the value of app:key_preview, however it was then subsequently overwritten with the null that a.getText(R.styleable.MyCustomView_key) was returning.

voopz.

这篇关于行为像工具:自定义视图中的文本?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！