我有一个非常简单的Objective-J webapp,它是一个标签和一个按钮。按下按钮时标签文本会发生变化。我想让按钮的标题也改变。如果我将更改语句放在下面的交换函数中(按下按钮时运行的函数),则webapp无法正常启动。
如何修改此代码,以便在标签文字为Good Bye Tommy时按钮读取Tommy Arrives?
@import <Foundation/CPObject.j>
@implementation AppController : CPObject
{
CPTextField label;
CPButton button;
}
// Launches UI in the App
- (void)applicationDidFinishLaunching:(CPNotification)aNotification
{
var theWindow = [[CPWindow alloc] initWithContentRect:CGRectMakeZero() styleMask:CPBorderlessBridgeWindowMask],contentView = [theWindow contentView];
label = [[CPTextField alloc] initWithFrame:CGRectMakeZero()];
[label setStringValue:@"Hello Tommy Jones!"];
[label setFont:[CPFont boldSystemFontOfSize:24.0]];
[label sizeToFit];
[label setAutoresizingMask:CPViewMinXMargin | CPViewMaxXMargin | CPViewMinYMargin | CPViewMaxYMargin];
[label setCenter:[contentView center]];
[contentView addSubview:label];
[label setAlignment:CPCenterTextAlignment];
button = [[CPButton alloc] initWithFrame: CGRectMake( CGRectGetWidth([contentView bounds])/2.0 - 50, CGRectGetMaxY([label frame]) + 10, 100, 24 )];
[button setAutoresizingMask:CPViewMinXMargin | CPViewMaxXMargin | CPViewMinYMargin | CPViewMaxYMargin];
[button setTitle:"Tommy Leaves"];
[button setTarget:self];
[button setAction:@selector(swap:)];
[contentView addSubview:button];
[theWindow orderFront:self];
// Uncomment the following line to turn on the standard menu bar.
[CPMenu setMenuBarVisible:YES];
}
// Executes when button is pressed
- (void)swap:(id)sender
{
if
([label stringValue] == "Hello Tommy Jones!") [label setStringValue:"Good Bye Tommy!"];
// [button setTitle:"Tommy Leaves"];
// [contentView addSubview:button];
else
[label setStringValue:"Hello Tommy Jones!"];
// [button setTitle:"Tommy Arrives"];
}
@end
答案 0 :(得分:0)
看起来你错过了一些大括号。 if语句或其else子句只接受一个“命令”,除非您将该批包装在{}
中。 E.g。
if ([label stringValue] == "Hello Tommy Jones!")
{
[label setStringValue:"Good Bye Tommy!"];
[button setTitle:"Tommy Leaves"];
}
else
{
[label setStringValue:"Hello Tommy Jones!"];
[button setTitle:"Tommy Arrives"];
}