自定义TextView - 在构造函数之前调用setText()

Question

我的CustomTextView有问题.我正在尝试从我的layout-xml文件中获取自定义值并在我的setText()方法中使用它.不幸的是,在构造函数之前调用了setText()方法,因此我无法在此方法中使用自定义值.

这是我的代码(细分到相关部分):

CustomTextView.class

public class CustomTextView extends TextView {

    private float mHeight;
    private final String TAG = "CustomTextView";
    private static final Spannable.Factory spannableFactory = Spannable.Factory.getInstance();

    public CustomTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        Log.d(TAG, "in CustomTextView constructor");
        TypedArray values = context.obtainStyledAttributes(attrs, R.styleable.CustomTextView);
        this.mHeight = values.getDimension(R.styleable.CustomTextView_cHeight, 20);
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        Log.d(TAG, "in setText function");
        Spannable s = getCustomSpannableString(getContext(), text);
        super.setText(s, BufferType.SPANNABLE);
    }

    private static Spannable getCustomSpannableString(Context context, CharSequence text) {
        Spannable spannable = spannableFactory.newSpannable(text);
        doSomeFancyStuff(context, spannable);
        return spannable;
    }

    private static void doSomeFancyStuff(Context context, Spannable spannable) {
        /*Here I'm trying to access the mHeight attribute.
        Unfortunately it's 0 though I set it to 24 in my layout 
        and it's correctly set in the constructor*/
    }
}

styles.xml

<declare-styleable name="CustomTextView">
    <attr name="cHeight" format="dimension"/>
</declare-styleable>

layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ctvi="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.mypackage.views.CustomTextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/my_fancy_string"
        android:textSize="16sp"
        ctvi:cHeight="24dp" />

</LinearLayout>

就像一个证据 - 这里是LogCat输出:

30912-30912/com.mypackage.views D/CustomTextView? in setText function
30912-30912/com.mypackage.views D/CustomTextView? in CustomTextView constructor

因此,您可以看到setText()在构造函数之前调用该方法.这有点奇怪,我不知道我需要改变什么才能cHeight在setText-method中使用我的自定义属性().

在此先感谢您的帮助!

Answer 1

它是基于属性值TextView super()调用您的构造setText()函数.

如果您在设置文本值时确实需要访问自定义属性,请同时使用文本的自定义属性.