Post not yet marked as solved
I have two lists side-by-side. I want to scroll any one of the lists, and the other one can scroll synchronously. Is there any way to achieve the effect? Any help will be appreciated.
struct ScrollTwoListsSynchronously: View {
let dataSet = [1,2,3,4,5]
var body: some View {
HStack{
List{
ForEach(dataSet,id:\.self){data in
Text(String(data))
}
}
.listStyle(PlainListStyle())
List{
ForEach(dataSet,id:\.self){data in
Text(String(data))
}
}
.listStyle(PlainListStyle())
}
}
}
In the simulator, everything is ok. However, in live preview mode of canvas, no keyboard pops up when I tap in the textfield. Did I miss anything? Or need more codes in preview?Thanks in advance.
Post not yet marked as solved
I make a toggle to control a textfield in a form. When I run it, I get a piece of warning:
invalid mode 'kCFRunLoopCommonModes' provided to CFRunLoopRunSpecific - break on _CFRunLoopError_RunCalledWithInvalidMode to debug. This message will only appear once per execution
What could I do to fix it? What's the harm if it's not fixed( App crashes, or...?). Any help will be appreciated.
struct ContentView: View {
@State private var toggle1 = true
@State private var str1 = "..."
var body: some View {
Form{
Section{
Toggle(isOn: $toggle1, label: {
Text("Toggle 1")})
}
Section{
if toggle1{
HStack{
Text("Toggle 1")
TextField("...", text: $str1)
}
}
}
.textFieldStyle(RoundedBorderTextFieldStyle())
}
}
}
Post not yet marked as solved
struct ContentView: View {
@State private var num = 0
var body: some View {
VStack{
Text(String(num))
.padding()
Button(action: {
num += 1
}, label: {Text("click+1")})
}
}
}
Question 1:
If I run the code above on simulator, I could get the value of "num" on the console by using"po _num".
However, if I run the code in previews(by "Debug-Attach to process"), I only get the error"error: :3:1: error: cannot find '_num' in scope" on the console by using"po _num"
Xcode 13.2.1
Question 2:
I could use "po num"/"po _num" to get the value of "num" with Xcode 12.
BUT, only "po _num" works in Xcode13. "po num" will raise the error:"
error: Couldn't lookup symbols: Preview2.ContentView.num.getter : Swift.Int"
Any help will be appreciated.
Post not yet marked as solved
struct ProblemSegmentTest: View {
@State private var select = 0
var body: some View {
VStack {
Picker("Test", selection: $select) {
Text("A").tag(0)
Text("B").tag(1)
Text("C").tag(2)
}
.pickerStyle(SegmentedPickerStyle())
}
.onTapGesture {
print("test")
}
}
}
I want to do sth when the picker is taped. However, when I apply ".onTapGesture" to the vstack, the picker's options can't be selected any more. Any help will be appreciated.
struct PickerStyleView: View {
@State private var num = 0
var body: some View {
Form{
Text("Number")
Picker(String(num), selection: $num, content: {
Text("5").tag(5)
Text("10").tag(10)
Text("15").tag(15)
Text("20").tag(20)
})
.pickerStyle(InlinePickerStyle())
}
}
}
Using InlinePickerStyle() and WheelPickerStyle() seems to be no difference.
What does "InlinePickerStyle()" refer to? And which case is "InlinePickerStyle()" suitable for in practice? Any help will be appreciated.
I downloaded sf symbol3 today. My Xcode is 12.5. When I write a simple code like:
Image(systemName: "gearshape")
everything is ok. However when the code turns to :
Image(systemName: "gearshape.circle")
nothing will be displayed.
Do I miss anything? Thanks in advance.
Post not yet marked as solved
I have an app released in the iOS store which is set to be price tier 1. I want to set it to be free for just next week. After that, the price should be back to price tier1 again. If I
tune it in App Store connect. Will it make my app to be in review again, or just take effect immediately? Thanks in advance.
Post not yet marked as solved
I wrote some code using LazyVGrid.
struct LazyVStackTestView: View {
let columnGridItem = Array(repeating: GridItem(), count: 3)
var body: some View {
GeometryReader{geo in
HStack{
Rectangle().frame(maxWidth: 300,maxHeight: 100)
LazyVGrid(columns: columnGridItem){
ForEach(1..<13) { btn in
Image(systemName: "plusminus.circle")
.resizable()
.scaledToFit()
.clipShape(Circle())
}
}
.padding()
.frame(maxWidth: geo.size.height*0.6, maxHeight: geo.size.height)
}.border(Color.black)
.padding()
}.border(Color.blue)
}
}
When run it on simulator(iPhone 11) in horizontal orientation, I get a 4rows3columns button pad that is what I want. But when I turn the simulator to vertical orientation and back to horizontal orientation immediately, the button pad becomes 3rows3columns! What had happened?
Any help will be appreciated.
I want to perform some code when the form is tapped. However the button in the form is affected by the onTapGesture either. I want the button tapped to execute the action block, not the onTapGesture block. How should I do? Thanks in advance.
struct TextFieldPopupView: View {
@State private var text = ""
@State private var isON = false
var body: some View {
Form{
Text("Hello")
TextField("Hello", text: $text)
.textFieldStyle(RoundedBorderTextFieldStyle())
Button(action: {
print("Button")
}, label: {Text("Button")})
Toggle(isOn: $isON, label: {
Text("Toggle")
})
}
.onTapGesture {
print("Form")
}
}
}
Post not yet marked as solved
I know I can use .redacted(reason: .placeholder) to make displayed data appear as generic placeholders. But how can I declare a custom RedactionReasons instance and use it? The examples of initializer in documentation seem not to be helpful. Thanks in advance.
In swift language guide-"Opaque Types"-"Differences Between Opaque Types and Protocol Types", it said:
"Another problem with this approach is that the shape transformations don’t nest. The result of flipping a triangle is a value of type Shape, and the protoFlip(:) function takes an argument of some type that conforms to the Shape protocol. However, a value of a protocol type doesn’t conform to that protocol; the value returned by protoFlip(:) doesn’t conform to Shape. This means code like protoFlip(protoFlip(smallTriange)) that applies multiple transformations is invalid because the flipped shape isn’t a valid argument to protoFlip(:)"
I can't understand why it said"a value of a protocol type doesn’t conform to that protocol; the value returned by protoFlip(:) doesn’t conform to Shape". The return value must conform to Shape. It's a fundamental requirement by function signature, isn't it?
Post not yet marked as solved
I want to set "ringer and alerts" sound in code.
MPVolumeView() seems like to control the system volume only. I have some sound effect(by invoking "AudioServicesPlaySystemSound(SystemSoundID:)") affected by "ringer and alerts" in my app. Even when the system volume is max, my app sound effect is still mute if "ringer and alerts" sound is mute. I have to tune "ringer and alerts" by "setting-sounds-ringer and alerts" manually.
Is there any programable way to set it? Any help will be greatly appreciated.
I drag a image.jpg into the assets.xcassets. And I want to read the jpg data in my code by
"var imageData = NSDataAsset(name: "image")?.data"
However, I get an error: "CoreUI: attempting to lookup a named data 'image' with a type that is not a data type in the AssetCatalog". And "imageData" is always nil.
Do I make a mistake or miss sth? Thanks in advance.
Post not yet marked as solved
I want to demonstrate a large size image(5184*3456) in a modal sheet with swiftui.
When I popup the sheet, memory usage increases from 20mb up to 100mb. However, when I dismiss the sheet, memory usage just decreases from 100mb to 92mb, wear and tear. I popup the sheet again, memory usage increases from 92mb back to 100mb.
Back and forth, memory usage always changes between 92mb and 100mb, instead of between 20mb and 100mb that I expect to. Why doesn't memory usage decrease to 20mb when the sheet dismiss? Why doesn't image been purged from memory when the sheet dismisses? I just want memory usage stays in a low level. How could I do? Thanks in advance.
struct IntroductionView: View {
@Environment(\EnvironmentValues.presentationMode) var presentation
var body: some View {
GeometryReader{geo in
VStack(alignment:.leading){
Image("image")
.resizable()
.aspectRatio(contentMode: .fill)
.frame(maxHeight:geo.size.height/4)
.clipped()
Spacer()
Button(action: {
presentation.wrappedValue.dismiss()
}, label: {
Text("Close")
}
}
}
}
}
test1229.