1
我已经创建了子类NSTextView
,这样我就可以删除文件并将文件的字符串内容复制到视图中(与将文件路径放入风景)。文本似乎正在丢失,但在丢弃后不可见。我可以看到光标已移动,甚至可以将删除的文本复制到视图外并粘贴到例如TextEdit中。我尝试在我的-performDragOperation:
方法的末尾添加[self setNeedsDisplay:YES]
,但行为没有改变。NSTextView拖放 - 删除后字符不可见
这是我迄今为止编写的代码。我想这不是实现这一点的最佳方式。我是新来的可可拖放实现。
-(NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
NSPasteboard *pb = [sender draggingPasteboard];
NSDragOperation dragOperation = [sender draggingSourceOperationMask];
if ([[pb types] containsObject:NSFilenamesPboardType]) {
if (dragOperation & NSDragOperationCopy) {
return NSDragOperationCopy;
}
}
if ([[pb types] containsObject:NSPasteboardTypeString]) {
if (dragOperation & NSDragOperationCopy) {
return NSDragOperationCopy;
}
}
return NSDragOperationNone;
}
-(BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
NSPasteboard *pb = [sender draggingPasteboard];
if ([[pb types] containsObject:NSFilenamesPboardType]) {
NSArray *filenames = [pb propertyListForType:NSFilenamesPboardType];
for (NSString *filename in filenames) {
NSStringEncoding encoding;
NSError * error;
NSString * fileContents = [NSString stringWithContentsOfFile:filename usedEncoding:&encoding error:&error];
if (error) {
// handle error
}
else {
[self setString:fileContents];
}
}
}
else if ([[pb types] containsObject:NSPasteboardTypeString]) {
NSString *draggedString = [pb stringForType:NSPasteboardTypeString];
[self setString:draggedString];
}
return YES;
}