Question

我如何实现以下代码：

    String dynamiccolor = "R.color." + selectedcolor;


    View MainActivity = findViewById(R.id.mainactivity);
    View root = MainActivity.getRootView();
    root.setBackgroundColor(getResources().getColor( dynamiccolor )); 
//here dynamiccolor variable is string, but for errorfree code must be INT

如何使用dynamiccolor变量，例如对于R.color.green？

Answer 1

将此方法添加到您的代码中：

protected final static int getResourceID
(final String resName, final String resType, final Context ctx)
{
    final int ResourceID =
        ctx.getResources().getIdentifier(resName, resType,
            ctx.getApplicationInfo().packageName);
    if (ResourceID == 0)
    {
        throw new IllegalArgumentException
        (
            "No resource string found with name " + resName
        );
    }
    else
    {
        return ResourceID;
    }
}

然后使用它：

// Assuming that you have your color resource in colors.xml
final int dynamiccolor = getResourceID(selectedcolor, "color", getApplicationContext());

Answer 2

如果你熟悉android，那么你就会知道R是一个静态类。所以R.color.green本质上包含一个映射到colors.xml文件的int。你可以尝试做这样的事情：

int dynamiccolor = -1;
switch(selectedcolor) {
   case "green": 
      dynamiccolor = R.color.green;
      break;
...
}

View MainActivity = findViewById(R.id.mainactivity);
View root = MainActivity.getRootView();    
root.setBackgroundColor(getResources().getColor( dynamiccolor ));

另一种类型的变量和动态值

2 个答案: