Question

安卓开发中，判断是否安装了qq

在安卓手机app开发中，能否通过设置一个按键，来判断手机中是否安装了qq；如果安装了qq，打开qq。这样的功能应该怎么实现，题主安卓开发小白，希望大神们能够解答详尽一些，感激不尽
搜索
复制

Answer 1

Android系统中，判断应用有无安装有两种方式：
1.根据包名判断,以下为判断代码：
public boolean checkApkExist(Context context, String packageName) {
if (packageName == null || “”.equals(packageName))
return false;
try {
ApplicationInfo info = context.getPackageManager()
.getApplicationInfo(packageName,
PackageManager.GET_UNINSTALLED_PACKAGES);
return true;
} catch (NameNotFoundException e) {
return false;
}
}

2. 根据Intent判断，以下为判断代码：
public boolean checkApkExist(Context context, Intent intent) {
List<ResolveInfo> list = context.getPackageManager().queryIntentActivities(intent, 0);
if(list.size() > 0){
return true;
}
return false;
}
public boolean checkApkExist(Context context, String packageName) {
if (packageName == null || “”.equals(packageName)) return false;
try {
ApplicationInfo info = context.getPackageManager() .getApplicationInfo(packageName, PackageManager.GET_UNINSTALLED_PACKAGES); return true;
} catch (NameNotFoundException e) { return false; }
}
public boolean checkApkExist(Context context, Intent intent) {
List<ResolveInfo> list = context.getPackageManager()
.queryIntentActivities(intent, 0);
if (list.size() > 0) {
return true;
}
return false;
}

Answer 2

Android系统中，判断应用有无安装有两种方式：
1.根据包名判断,以下为判断代码：
public boolean checkApkExist(Context context, String packageName) {
if (packageName == null || “”.equals(packageName))
return false;
try {
ApplicationInfo info = context.getPackageManager()
.getApplicationInfo(packageName,
PackageManager.GET_UNINSTALLED_PACKAGES);
return true;
} catch (NameNotFoundException e) {
return false;
}
}
2. 根据Intent判断，以下为判断代码：
public boolean checkApkExist(Context context, Intent intent) {
List<ResolveInfo> list = context.getPackageManager().queryIntentActivities(intent, 0);
if(list.size() > 0){
return true;
}
return false;
}
public boolean checkApkExist(Context context, String packageName) {
if (packageName == null || “”.equals(packageName)) return false;
try {
ApplicationInfo info = context.getPackageManager() .getApplicationInfo(packageName, PackageManager.GET_UNINSTALLED_PACKAGES); return true;
} catch (NameNotFoundException e) { return false; }
}
public boolean checkApkExist(Context context, Intent intent) {
List<ResolveInfo> list = context.getPackageManager()
.queryIntentActivities(intent, 0);
if (list.size() > 0) {
return true;
}
return false;
}

Answer 3

public static final boolean isApkInstalled(Context context, String packageName) {
try {
context.getPackageManager().getApplicationInfo(packageName, PackageManager.GET_UNINSTALLED_PACKAGES);
return true;
} catch (NameNotFoundException e) {
return false;
}
}
packageName = "com.tencent.mobileqq"