防止多行TextView不必要地扩展到它的最大宽度

Question

扩展为多行的TextView似乎会自动扩展以适应其最大可能宽度.我怎样才能防止这种情况发生？

这是一个示例布局(test.xml)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/white">
<TextView
android:background="@color/green"
android:layout_alignParentRight="true"
android:id="@+id/foo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="right"
android:text="This is the message a much shorter message"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@color/black" />
</RelativeLayout>

如果我在左边添加一个边距,它会正确缩小TextView的宽度(不重新格式化内容),但是必须根据TextView的内容计算边距的大小.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/white">
<TextView
android:layout_marginLeft="32dp"
android:background="@color/green"
android:layout_alignParentRight="true"
android:id="@+id/foo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="right"
android:text="This is the message a much shorter message"
android:textAppearance="?android:attr/textAppearanceMedium"
android:textColor="@color/black" />
</RelativeLayout>

Answer 1

您可以使用自定义TextView和重写方法onMeasure()来计算宽度:

public class WrapWidthTextView extends TextView {

...

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    Layout layout = getLayout();
    if (layout != null) {
        int width = (int)FloatMath.ceil(getMaxLineWidth(layout))
                + getCompoundPaddingLeft() + getCompoundPaddingRight();
        int height = getMeasuredHeight();            
        setMeasuredDimension(width, height);
    }
}

private float getMaxLineWidth(Layout layout) {
    float max_width = 0.0f;
    int lines = layout.getLineCount();
    for (int i = 0; i < lines; i++) {
        if (layout.getLineWidth(i) > max_width) {
            max_width = layout.getLineWidth(i);
        }
    }
    return max_width;
}

}

Answer 2

useandroid:padding="32dp" 它可以帮助你填充，如果你想从左边使用填充android:paddingLeft="32dp"