下面是我的例子，如果有人觉得有用，我就从我的应用程序中启动条形码/QR码扫描仪

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();
}

传递包名和你想要显示的消息，如果包没有安装;-)

void openApp(String appPackageName,String message){
    Intent launchIntent = getPackageManager().getLaunchIntentForPackage(appPackageName);
    if (launchIntent != null) {
        startActivity(launchIntent);
    } else {
        Toast.makeText(MainActivity.this, message, Toast.LENGTH_LONG).show();
        startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse("https://play.google.com/store/apps/details?id=" + appPackageName)));
    }
}

如果你知道数据和安装的包的反应，你只需在启动之前将这些信息添加到你的intent实例中。

如果你可以访问其他应用程序的AndroidManifest，你可以在那里看到所有需要的信息。

检查应用程序，避免任何崩溃。如果应用程序在手机中存在，那么它将被启动，否则它将在谷歌Play中搜索。如果手机没有安装谷歌Play app，手机会通过浏览器在谷歌Play Store中搜索:

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);
    }
}

启动新活动的步骤如下:

1.获取包的意图

2.如果意图为空重定向用户到播放商店

3.如果意图不为空，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);
    }
}

试试下面的代码:

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.setComponent(new ComponentName("package_name", "Class_name"));
if (intent.resolveActivity(getPackageManager()) != null) 
{
   startActivity(intent);
}