在多个活动之间传递数据

Question

I have three activities, say I have the data from ActivityA, and I want ActivityC to retrieve it but it must go through ActivityB which I don't want it do anything about the passed data. Is there anyway to do it?

I have tried

ActivityA.java

Intent i = new Intent(this, ActivityB.class);
i.putExtra("DATA1", "Hello");
i.putExtra("DATA2", "World");
startActivity(i);

ActivityB.java doesn't do anything about it but it must be seen before ActivityC.

ActivityC.java

Bundle b = getIntent().getExtras();
String data1 = b.getString("DATA1");
String data2 = b.getString("DATA2");

But it gives me this exception

11-30 02:12:05.165: W/dalvikvm(1134): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
11-30 02:12:05.185: E/AndroidRuntime(1134): FATAL EXCEPTION: main
11-30 02:12:05.185: E/AndroidRuntime(1134): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.src.test/com.src.test.ActivityC}: java.lang.NullPointerException
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.os.Looper.loop(Looper.java:123)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.ActivityThread.main(ActivityThread.java:4627)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at java.lang.reflect.Method.invokeNative(Native Method)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at java.lang.reflect.Method.invoke(Method.java:521)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at dalvik.system.NativeStart.main(Native Method)
11-30 02:12:05.185: E/AndroidRuntime(1134): Caused by: java.lang.NullPointerException
11-30 02:12:05.185: E/AndroidRuntime(1134):     at com.src.test.ActivityC.onCreate(ActivityC.java:98)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
11-30 02:12:05.185: E/AndroidRuntime(1134):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)

which points to String data1 = b.getString("DATA1");

Is there any way to do this correctly?

Any help would be greatly appreciated.

Answer 1

从B到C调用时，添加到您的意图：

myIntent.putExtras(getIntent().getExtras());

Answer 2

It's because your ActivityB doesn't push it to ActivityC:

Intent newIntent = new Intent(ActivityB.this, ActivityC.class);
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
    newIntent.putExtras(bundle);
}
startActivity(newIntent);

Answer 3

do this in activity B:

Bundle b = getIntent().getExtras();
String data1 = b.getString("DATA1");
String data2 = b.getString("DATA2");


Intent i = new Intent(this, ActivityC.class);
i.putExtra("DATA1", data1);
i.putExtra("DATA2", data2);
startActivity(i);