catch

本参考资料用于Processing 3.0+。 如果你使用的是前一版本,请在使用软件帮助菜单内的参考资料。. If you see any errors or have suggestions, please let us know. If you prefer a more technical reference, visit the Processing Core Javadoc and Libraries Javadoc.

名称

catch

示例
 BufferedReader reader;

String line;

 

void setup()
{  
// Open the file from the createWriter() example   reader = createReader("positions.txt");


  }  
void draw()
{  
try{
line = reader.readLine();


  } catch (IOException e)
{
e.printStackTrace();


line = null;


  }   if (line == null)
{
// Stop reading because of an error or file is empty     noLoop();


  } else{
String[] pieces = split(line, TAB);


int x = int(pieces[0]);


int y = int(pieces[1]);


point(x, y);


   }
  } 
描述 The catch keyword is used with try to handle exceptions. Sun’s Java documentation defines an exception as “an event, which occurs during the execution of a program, that disrupts the normal flow of the program’s instructions.” This could be, for example, an error while a file is read.
语法
 try{  
tryStatements
  } catch (exception)
{  
catchStatements
  }  
参数
tryStatements if this code throws an exception, then the code in “catch” is run
exception the Java exception that was thrown
catchStatements code that handles the exception

Updated on October 2, 2018 05:02:16pm EDT

catch