android canvas drawText从宽度设置字体大小？

这是一种更有效的方法：

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);}

然后，您所要做的就是

setTextSizeForWidth(paint, 400, str);

为了获得更高的效率，您可以使它

Rect