android canvas drawText从宽度设置字体大小？

Z时代
2024-01-10
分类：问答

我想canvas使用指定宽度绘制文本.drawtext

例如，400px无论输入文本是什么，文本的宽度都应始终为。

如果输入文本较长，则将减小字体大小；如果输入文本较短，则将相应地增大字体大小。

回答：

这是一种更有效的方法：

/**
 * Sets the text size for a Paint object so a given string of text will be a
 * given width.
 * 
 * @param paint
 *            the Paint to set the text size for
 * @param desiredWidth
 *            the desired width
 * @param text
 *            the text that should be that width
 */
private static void setTextSizeForWidth(Paint paint, float desiredWidth,
        String text) {
    // Pick a reasonably large value for the test. Larger values produce
    // more accurate results, but may cause problems with hardware
    // acceleration. But there are workarounds for that, too; refer to
    // http://stackoverflow.com/questions/6253528/font-size-too-large-to-fit-in-cache
    final float testTextSize = 48f;
    // Get the bounds of the text, using our testTextSize.
    paint.setTextSize(testTextSize);
    Rect bounds = new Rect();
    paint.getTextBounds(text, 0, text.length(), bounds);
    // Calculate the desired size as a proportion of our testTextSize.
    float desiredTextSize = testTextSize * desiredWidth / bounds.width();
    // Set the paint for that size.
    paint.setTextSize(desiredTextSize);
}