Question

如何从用户输入更改jframe的不透明度，比如说从微调器？

int opacity = 7;
double dOpacity = opacity/10;
String sOpacity = Double.toString(dOpacity)+"f";
this.setOpacity(sOpacity); //???

上面的代码会产生一堆错误。无论如何得到不透明度数字，比方说6，然后将其转换为'this.setOpacity（sOpacity）;'的值会接受吗？

错误：

Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: GuiClock.Main.setOpacity
    at GuiClock.Main.cinitComponents(Main.java:97)
    at GuiClock.Main.<init>(Main.java:16)
    at GuiClock.Main$6.run(Main.java:168)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Answer 1

代码中的

：dOpacity= 0.0

    int opacity = 7;
    float dOpacity = (float)opacity/10; //casting to float , here dOpacity=0.7
    String sOpacity = Float.toString(dOpacity)+"f"; // sOpacity="0.7f"
    this.setOpacity(Float.parseFloat(sOpacity)); //setOpacity(0.7f);

Answer 2

setOpacity方法使用float作为参数。您正在传递String。

尝试this.setOpacity(Float.parseFloat(sOpacity));

Answer 3

您正在将一个String作为参数插入setOpacity方法，该方法只需要双精度。

Java JFrame设置自定义不透明度

3 个答案: