TextView.java 文件源码

/**
 * Sets the transformation that is applied to the text that this
 * TextView is displaying.
 *
 * @attr ref android.R.styleable#TextView_password
 * @attr ref android.R.styleable#TextView_singleLine
 */
public final void setTransformationMethod(TransformationMethod method) {
    if (method == mTransformation) {
        // Avoid the setText() below if the transformation is
        // the same.
        return;
    }
    if (mTransformation != null) {
        if (mText instanceof Spannable) {
            ((Spannable) mText).removeSpan(mTransformation);
        }
    }

    mTransformation = method;

    setText(mText);
}