＆QUOT;长度必须至少为1（是-1）＆QUOT;是什么原因导致这个问题以及如何解决呢？ [英] "Length must be at least 1 (was -1)" what causes this and how do I fix it?

问题描述

我得到这一行的code错误：

I get the error with this line of code:

这是什么的getBackground（）是这样的：

public class MyClass {

  ...

  private String background;

  public String getBackground() {
    return background;
  }

  ...
}

我已经验证了 Col​​or.parseColor 需要一个字符串。为什么发生这种情况，我怎么可以让编译器高兴吗？

I've verified that Color.parseColor takes a string. Why this is happening, and how I can make the compiler happy?

这不会停止运行的应用程序，所以也许这是一个静态分析器的事情吗？我试图把来自的getBackground（）的返回值在本地和检查，这是不空，不得不长度（）＆GT; = 1 ，但并没有出现解决任何事情。

This doesn't stop the app from running, so perhaps this a static analyzer thing? I tried putting the return value from getBackground() in a local and checking that it was non-null and had length() >= 1, but that didn't appear to solve anything.

推荐答案

看起来pretty的很像问题与静态分析检查之一。如果你通过字符串文字到颜色＃parseColor（字符串），例如： Col​​or.parseColor（＃EEE）; 问题消失
。 貌似静态分析是不够聪明的推断值传递的（这是返回值的getBackground（））的非空在所有可能的情况，从而它表明你的可能的这个值是空或空。如果您确定颜色字符串不为空的，你可以只燮preSS它像这样：

Looks pretty much like the issue with one of the static analyzer inspections. If you pass String literal to the Color#parseColor(String), e.g. Color.parseColor("#eee"); the issue disappears.
Looks like static analyzer isn't smart enough to infer that the value you pass in (which is return value of getBackground()) is non-null in all possible cases, thus it shows you that possibly this value is null or empty. If you're sure that color String is non-null you can just suppress it like so:

//noinspection ResourceType
view.setColor(Color.parseColor(model.getColor().getBackground()));

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