Java 如何从 Android 中的另一个应用程序启动 Activity

How to launch an Activity from another Application in Android

提问by Bastian

I want to launch an installed package from my Android application. I assume that it is possible using intents, but I didn't find a way of doing it. Is there a link, where to find the information?

我想从我的 Android 应用程序启动一个已安装的包。我认为可以使用意图，但我没有找到这样做的方法。有没有链接，在哪里可以找到信息？

回答by WarrenFaith

If you know the data and the action the installed package react on, you simply should add these information to your intent instance before starting it.

如果您知道数据和安装的包所反应的操作，您只需在启动它之前将这些信息添加到您的意图实例。

If you have access to the AndroidManifest of the other app, you can see all needed information there.

如果您有权访问其他应用程序的 AndroidManifest，您可以在那里看到所有需要的信息。

回答by Bastian

I found the solution. In the manifest file of the application I found the package name: com.package.address and the name of the main activity which I want to launch: MainActivity The following code starts this application:

我找到了解决方案。在应用程序的清单文件中，我找到了包名：com.package.address 和我想启动的主要活动的名称：MainActivity 下面的代码启动了这个应用程序：

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setComponent(new ComponentName("com.package.address","com.package.address.MainActivity"));
startActivity(intent);

回答by andep

If you don't know the main activity, then the package name can be used to launch the application.

如果您不知道主要活动，则可以使用包名称来启动应用程序。

Intent launchIntent = getPackageManager().getLaunchIntentForPackage("com.package.address");
if (launchIntent != null) { 
    startActivity(launchIntent);//null pointer check in case package name was not found
}

回答by Jared Burrows

I know this has been answered but here is how I implemented something similar:

我知道这已经得到了回答，但这是我如何实现类似的东西：

Intent intent = getPackageManager().getLaunchIntentForPackage("com.package.name");
if (intent != null) {
    // We found the activity now start the activity
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
} else {
    // Bring user to the market or let them choose an app?
    intent = new Intent(Intent.ACTION_VIEW);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intent.setData(Uri.parse("market://details?id=" + "com.package.name"));
    startActivity(intent);
}

Even better, here is the method:

更好的是，这里是方法：

public void startNewActivity(Context context, String packageName) {
    Intent intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent != null) {
        // We found the activity now start the activity
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    } else {
        // Bring user to the market or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setData(Uri.parse("market://details?id=" + packageName));
        context.startActivity(intent);
    }
}

Removed duplicate code:

删除重复代码：

public void startNewActivity(Context context, String packageName) {
    Intent intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    if (intent == null) {
        // Bring user to the market or let them choose an app?
        intent = new Intent(Intent.ACTION_VIEW);
        intent.setData(Uri.parse("market://details?id=" + packageName));
    }
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(intent);
}

回答by Tine M.

Here is my example of launching bar/QR code scanner from my app if someone finds it useful

这是我从我的应用程序启动条码/二维码扫描仪的示例，如果有人觉得它有用

Intent intent = new Intent("com.google.zxing.client.android.SCAN");
intent.setPackage("com.google.zxing.client.android");

try 
{
    startActivityForResult(intent, SCAN_REQUEST_CODE);
} 
catch (ActivityNotFoundException e) 
{
    //implement prompt dialog asking user to download the package
    AlertDialog.Builder downloadDialog = new AlertDialog.Builder(this);
    downloadDialog.setTitle(stringTitle);
    downloadDialog.setMessage(stringMessage);
    downloadDialog.setPositiveButton("yes",
            new DialogInterface.OnClickListener() 
            {
                public void onClick(DialogInterface dialogInterface, int i) 
                {
                    Uri uri = Uri.parse("market://search?q=pname:com.google.zxing.client.android");
                    Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                    try
                    {
                        myActivity.this.startActivity(intent);
                    }
                    catch (ActivityNotFoundException e)
                    {
                        Dialogs.this.showAlert("ERROR", "Google Play Market not found!");
                    }
                }
            });
    downloadDialog.setNegativeButton("no",
            new DialogInterface.OnClickListener() 
            {
                public void onClick(DialogInterface dialog, int i) 
                {
                    dialog.dismiss();
                }
            });
    downloadDialog.show();
}

回答by Karima Engineer

// check for the app if it exist in the phone it will lunch it otherwise, it will search for the app in google play app in the phone and to avoid any crash, if no google play app installed in the phone, it will search for the app in the google play store using the browser : 

 public void onLunchAnotherApp() {

        final String appPackageName = getApplicationContext().getPackageName();

        Intent intent = getPackageManager().getLaunchIntentForPackage(appPackageName);
        if (intent != null) {

            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(intent);

        } else {

            onGoToAnotherInAppStore(intent, appPackageName);

        }

    }

    public void onGoToAnotherInAppStore(Intent intent, String appPackageName) {

        try {

            intent = new Intent(Intent.ACTION_VIEW);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent.setData(Uri.parse("market://details?id=" + appPackageName));
            startActivity(intent);

        } catch (android.content.ActivityNotFoundException anfe) {

            intent = new Intent(Intent.ACTION_VIEW);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent.setData(Uri.parse("http://play.google.com/store/apps/details?id=" + appPackageName));
            startActivity(intent);

        }

    }

回答by Sharath kumar

Steps to launch new activity as follows:

启动新活动的步骤如下：

1.Get intent for package

1.获取包装意向

2.If intent is null redirect user to playstore

2.如果意图为空，则将用户重定向到Playstore

3.If intent is not null open activity

3.如果意图不是空打开活动

public void launchNewActivity(Context context, String packageName) {
    Intent intent = null;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.CUPCAKE) {
        intent = context.getPackageManager().getLaunchIntentForPackage(packageName);
    }
    if (intent == null) {
        try {
            intent = new Intent(Intent.ACTION_VIEW);
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            intent.setData(Uri.parse("market://details?id=" + packageName));
            context.startActivity(intent);
        } catch (android.content.ActivityNotFoundException anfe) {
            startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=" + packageName)));
        }
    } else {
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intent);
    }
}

回答by Ahamadullah Saikat

// in onCreate method
String appName = "Gmail";
String packageName = "com.google.android.gm";
openApp(context, appName, packageName);

public static void openApp(Context context, String appName, String packageName) {
    if (isAppInstalled(context, packageName))
        if (isAppEnabled(context, packageName))
            context.startActivity(context.getPackageManager().getLaunchIntentForPackage(packageName));
        else Toast.makeText(context, appName + " app is not enabled.", Toast.LENGTH_SHORT).show();
    else Toast.makeText(context, appName + " app is not installed.", Toast.LENGTH_SHORT).show();
}

private static boolean isAppInstalled(Context context, String packageName) {
    PackageManager pm = context.getPackageManager();
    try {
        pm.getPackageInfo(packageName, PackageManager.GET_ACTIVITIES);
        return true;
    } catch (PackageManager.NameNotFoundException ignored) {
    }
    return false;
}

private static boolean isAppEnabled(Context context, String packageName) {
    boolean appStatus = false;
    try {
        ApplicationInfo ai = context.getPackageManager().getApplicationInfo(packageName, 0);
        if (ai != null) {
            appStatus = ai.enabled;
        }
    } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
    }
    return appStatus;
}

回答by Vignesh KM

If you want to open specific activity of another application we can use this.

如果您想打开另一个应用程序的特定活动，我们可以使用它。

Intent intent = new Intent(Intent.ACTION_MAIN, null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
final ComponentName cn = new ComponentName("com.android.settings", "com.android.settings.fuelgauge.PowerUsageSummary");
intent.setComponent(cn);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
try 
{
    startActivity(intent)
}catch(ActivityNotFoundException e){
    Toast.makeText(context,"Activity Not Found",Toast.LENGTH_SHORT).show()
}

If you must need other application, instead of showing Toast you can show a dialog. Using dialog you can bring the user to Play-Store to download required application.

如果您必须需要其他应用程序，您可以显示一个对话框而不是显示 Toast。使用对话框，您可以将用户带到 Play-Store 下载所需的应用程序。

回答by mayank1513

Edit depending on comment

根据评论编辑

In some versions - as suggested in comments - the exception thrown may be different.

在某些版本中 - 正如评论中所建议的那样 - 抛出的异常可能会有所不同。

Thus the solution below is slightly modified

因此，下面的解决方案略有修改

Intent launchIntent = null;
try{
   launchIntent = getPackageManager().getLaunchIntentForPackage("applicationId");
} catch (Exception ignored) {}

if(launchIntent == null){
    startActivity(new Intent(Intent.ACTION_VIEW).setData(Uri.parse("https://play.google.com/store/apps/details?id=" + "applicationId")));
} else {
    startActivity(launchIntent);
}

Original Answer

原答案

Although answered well, there is a pretty simple implementation that handles if the app is not installed. I do it like this

尽管回答得很好，但有一个非常简单的实现可以处理未安装应用程序。我这样做

try{
    startActivity(getPackageManager().getLaunchIntentForPackage("applicationId"));
} catch (PackageManager.NameNotFoundException e) {
    startActivity(new Intent(Intent.ACTION_VIEW).setData(Uri.parse("https://play.google.com/store/apps/details?id=" + "applicationId")));
}

Replace "applicationId" with the package that you want to open such as com.google.maps, etc.

将“applicationId”替换为您要打开的包，例如 com.google.maps 等。