Launch Options

Set launch options

Example

var launchOption = new MLaunchOption()
{
    StartVersion = myversion,
    Session = MSession.GetOfflineSession("tester123"),

    Path = new MinecraftPath(),
    MaximumRamMb = 4096,
    JavaPath = "javaw.exe",
    JVMArguments = new string[] { },

    ServerIp = "mc.hypixel.net",
    ServerPort = 25565,

    ScreenWidth = 1600,
    ScreenHeight = 900,

    VersionType = "CmlLauncher",
    GameLauncherName = "CmlLauncher",
    GameLauncherVersion = "2",

    FullScreen = false,

    // Only macOS
    DockName = "",
    DockIcon = "",
};

Properties

StartVersion

Type: MVersion

The version you want to launch. If you launch the game using CMLauncher, you don't have to set this property. CMLauncher will automatically get the version and set this.

Session

Type: MSession Optional

See Login and Sessions for how to log in Minecraft and get game session.

Set the username, uuid, and access_token of the player. It is used to connect to an online-mode server or a realm. A session created by MSession.GetOfflineSession can't connect these servers. If the value of this property is null, an ArgumentException will be thrown.

Path

Type: MinecraftPath Optional

Sets base directory for launching. You should not set this property if you use CMLauncher.

JavaVersion

Type: string Optional

Sets the java version. It overrides default java version. The default java version is determined by FileChecker.

JavaPath

Type: string Optional

Sets the java path. It overrides default java binary path. The default java binary path is determined by FileChecker.

MaximumRamMb

Type: int Optional

Sets the -Xmx JVM parameter. It is used to set the maximum heap size of Minecraft. If the value of this property is less than 1, ArgumentException will be thrown. The default value is 1024. (1 GB) Note: You can't set this property to any number higher than 1024 when using 32bit Java.

MinimumRamMb

Type: int Optional

Sets the -Xms JVM parameter. It is used to set the minimum heap size of Minecraft. If you set this property higher than MaximumRamMb, ArgumentException will be thrown.

VersionType

Type: string Optional

Sets ${version_type}. An empty value will set ${version_type} to the TypeStr property of the MVersion class. VersionType will be shown bottom left of main menu in minecraft. Old minecraft version doesn't support this option.

GameLauncherName

Type: string Optional

Sets ${launcher_name}. An empty value will set ${launcher_name} to minecraft-launcher, which is the same as the default value of the Mojang launcher.

GameLauncherVersion

Type: string Optional

Sets ${launcher_version}. An empty value will set ${launcher_name} to 2, which is the same as the default value of the Mojang launcher.

ServerIp

Type: string Optional

Connecting to a server directly when Minecraft is loading is done. This option doesn't work in 1.15. It's a Minecraft bug. You can't use SRV record.

ServerPort

Type: int Optional

Sets the server port of the ServerIp property. The default value is 25565. Valid range : 0-65535

JVMArguments

Type: string[] Optional

Sets the JVM parameters. If this property is null, the launcher uses the default JVM parameters. Default JVM parameters:

-XX:+UnlockExperimentalVMOptions,
-XX:+UseG1GC,
-XX:G1NewSizePercent=20,
-XX:G1ReservePercent=20,
-XX:MaxGCPauseMillis=50,
-XX:G1HeapRegionSize=16M

ScreenWidth / ScreenHeight

Type: int Optional

Sets the resolution of Minecraft. It works when value of the two options is bigger than 0. Old Minecraft versions don't support these options. If value of the two options is 0, use default setting of minecraft. If one of these options is negative, ArgumentException will be thrown.

FullScreen

Type: bool Optional

If this property is true, Minecraft will be fullscreen (not permanently). Old Minecraft versions don't support this option. Some forge versions also don't support this option.

DockName

Type: string Optional

Sets the macOS dock name of Minecraft. In some macOS versions, you must set this option. Known Issues

DockIcon

Type: string Optional

Sets the macOS dock icon of minecraft. It should be an absolute file path to an image that has the dimensions 256x256 and is of the icns format.