如何从我的 Android 应用程序 Activity 启动另一个应用程序

How to Launch another application from My Android app Activity

我想从我的应用程序开始启动 facebook 我已经尝试了以下代码

 public void text(String MessageBody) {
        
        public void text(String MessageBody) { 
        try { 
            Toast.makeText(getApplicationContext(), "salam its working", Toast.LENGTH_LONG).show(); 
            PackageManager pm = getPackageManager(); 
            if(MessageBody=="facebook") { 
                Intent intent = pm.getLaunchIntentForPackage("com.android.camera"); 
                startActivity(intent); 
            } 
        } catch(Exception e) { 
            Toast.makeText(getApplicationContext(), e.toString(), Toast.LENGTH_LONG).show(); 
        }
    }

这在 activity class 中运行良好,但我正在寻找一种在非 activity class.[=14= 中运行相同代码的方法]

存在上下文错误,现在当我在非 activity class

中启动 activity 方法时它可以正常工作
    Context c;
    Toast.makeText(context, message1, Toast.LENGTH_LONG).show();
    PackageManager pm = context.getPackageManager();
    Intent intentt =pm.getLaunchIntentForPackage("com.facebook.katana");
    context.startActivity(intentt);

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