使文本框输入只能0-100的数字也就是百分比而且数字小于20就自动改为20，应为这个百分比是用于设置窗口透明度所以下限我设为20-The text box to enter only the numbers from the 0-100 number is less than 20 percent and is automatically changed to 20, this percentage should be used to set window transparency, so I set the lower limit of 20