【发布时间】：2017-11-22 12:14:33
【问题描述】：
我已成功使用 Flutter 插件 Image_picker 选择图像，以便我可以将它们用于上传、显示等...我想知道是否有人对如何修改此插件以也查看视频并允许他们有任何指导被选择并用于上传等......
如果有人对如何继续或示例代码有指导，请寻找 iOS 和 Android 修改。我已经取得了一些进展，但仍然需要让相机保存视频并能够呈现。到目前为止，我将发布代码更改。我让它选择一个视频，但它不会显示回应用程序。
// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
@import UIKit;
#import <MobileCoreServices/MobileCoreServices.h>
#import "ImagePickerPlugin.h"
@interface ImagePickerPlugin ()<UINavigationControllerDelegate, UIImagePickerControllerDelegate>
@end
static const int SOURCE_ASK_USER = 0;
static const int SOURCE_CAMERA = 1;
static const int SOURCE_GALLERY = 2;
@implementation ImagePickerPlugin {
FlutterResult _result;
NSDictionary *_arguments;
UIImagePickerController *_imagePickerController;
UIViewController *_viewController;
}
+ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
FlutterMethodChannel *channel =
[FlutterMethodChannel methodChannelWithName:@"image_picker"
binaryMessenger:[registrar messenger]];
UIViewController *viewController =
[UIApplication sharedApplication].delegate.window.rootViewController;
ImagePickerPlugin *instance = [[ImagePickerPlugin alloc] initWithViewController:viewController];
[registrar addMethodCallDelegate:instance channel:channel];
}
- (instancetype)initWithViewController:(UIViewController *)viewController {
self = [super init];
if (self) {
_viewController = viewController;
_imagePickerController = [[UIImagePickerController alloc] init];
}
return self;
}
- (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
if (_result) {
_result([FlutterError errorWithCode:@"multiple_request"
message:@"Cancelled by a second request"
details:nil]);
_result = nil;
}
if ([@"pickImage" isEqualToString:call.method]) {
_imagePickerController.modalPresentationStyle = UIModalPresentationCurrentContext;
_imagePickerController.delegate = self;
_result = result;
_arguments = call.arguments;
int imageSource = [[_arguments objectForKey:@"source"] intValue];
switch (imageSource) {
case SOURCE_ASK_USER:
[self showImageSourceSelector];
break;
case SOURCE_CAMERA:
[self showCamera];
break;
case SOURCE_GALLERY:
[self showPhotoLibrary];
break;
default:
result([FlutterError errorWithCode:@"invalid_source"
message:@"Invalid image source."
details:nil]);
break;
}
} else {
result(FlutterMethodNotImplemented);
}
}
- (void)showImageSourceSelector {
UIAlertControllerStyle style = UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad
? UIAlertControllerStyleAlert
: UIAlertControllerStyleActionSheet;
UIAlertController *alert =
[UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:style];
UIAlertAction *camera = [UIAlertAction actionWithTitle:@"Take Photo"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
[self showCamera];
}];
UIAlertAction *library = [UIAlertAction actionWithTitle:@"Choose Photo"
style:UIAlertActionStyleDefault
handler:^(UIAlertAction *action) {
[self showPhotoLibrary];
}];
UIAlertAction *cancel =
[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil];
[alert addAction:camera];
[alert addAction:library];
[alert addAction:cancel];
[_viewController presentViewController:alert animated:YES completion:nil];
}
- (void)showCamera {
// Camera is not available on simulators
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
_imagePickerController.sourceType = UIImagePickerControllerCameraCaptureModeVideo;
[_viewController presentViewController:_imagePickerController animated:YES completion:nil];
} else {
[[[UIAlertView alloc] initWithTitle:@"Error"
message:@"Camera not available."
delegate:nil
cancelButtonTitle:@"OK"
otherButtonTitles:nil] show];
}
}
- (void)showPhotoLibrary {
// No need to check if SourceType is available. It always is.
//_imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
_imagePickerController.mediaTypes =[UIImagePickerController availableMediaTypesForSourceType:_imagePickerController.sourceType];
[_viewController presentViewController:_imagePickerController animated:YES completion:nil];
}
- (void)imagePickerController:(UIImagePickerController *)picker
didFinishPickingMediaWithInfo:(NSDictionary<NSString *, id> *)info {
[_imagePickerController dismissViewControllerAnimated:YES completion:nil];
UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
NSURL *videoURL = [info objectForKey:UIImagePickerControllerMediaURL];
if (image == nil) {
image = [info objectForKey:UIImagePickerControllerOriginalImage];
} else {
image = [self normalizedImage:image];
}
if (videoURL == nil) {
} else {
//image = videoURL;
}
NSNumber *maxWidth = [_arguments objectForKey:@"maxWidth"];
NSNumber *maxHeight = [_arguments objectForKey:@"maxHeight"];
if (maxWidth != (id)[NSNull null] || maxHeight != (id)[NSNull null]) {
image = [self scaledImage:image maxWidth:maxWidth maxHeight:maxHeight];
}
NSData *data = UIImageJPEGRepresentation(image, 1.0);
NSString *tmpDirectory = NSTemporaryDirectory();
NSString *guid = [[NSProcessInfo processInfo] globallyUniqueString];
// TODO(jackson): Using the cache directory might be better than temporary
// directory.
NSString *tmpFile = [NSString stringWithFormat:@"image_picker_%@.jpg", guid];
NSString *tmpPath = [tmpDirectory stringByAppendingPathComponent:tmpFile];
if ([[NSFileManager defaultManager] createFileAtPath:tmpPath contents:data attributes:nil]) {
_result(tmpPath);
} else {
_result([FlutterError errorWithCode:@"create_error"
message:@"Temporary file could not be created"
details:nil]);
}
_result = nil;
_arguments = nil;
}
// The way we save images to the tmp dir currently throws away all EXIF data
// (including the orientation of the image). That means, pics taken in portrait
// will not be orientated correctly as is. To avoid that, we rotate the actual
// image data.
// TODO(goderbauer): investigate how to preserve EXIF data.
- (UIImage *)normalizedImage:(UIImage *)image {
if (image.imageOrientation == UIImageOrientationUp) return image;
UIGraphicsBeginImageContextWithOptions(image.size, NO, image.scale);
[image drawInRect:(CGRect){0, 0, image.size}];
UIImage *normalizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return normalizedImage;
}
- (UIImage *)scaledImage:(UIImage *)image
maxWidth:(NSNumber *)maxWidth
maxHeight:(NSNumber *)maxHeight {
double originalWidth = image.size.width;
double originalHeight = image.size.height;
bool hasMaxWidth = maxWidth != (id)[NSNull null];
bool hasMaxHeight = maxHeight != (id)[NSNull null];
double width = hasMaxWidth ? MIN([maxWidth doubleValue], originalWidth) : originalWidth;
double height = hasMaxHeight ? MIN([maxHeight doubleValue], originalHeight) : originalHeight;
bool shouldDownscaleWidth = hasMaxWidth && [maxWidth doubleValue] < originalWidth;
bool shouldDownscaleHeight = hasMaxHeight && [maxHeight doubleValue] < originalHeight;
bool shouldDownscale = shouldDownscaleWidth || shouldDownscaleHeight;
if (shouldDownscale) {
double downscaledWidth = (height / originalHeight) * originalWidth;
double downscaledHeight = (width / originalWidth) * originalHeight;
if (width < height) {
if (!hasMaxWidth) {
width = downscaledWidth;
} else {
height = downscaledHeight;
}
} else if (height < width) {
if (!hasMaxHeight) {
height = downscaledHeight;
} else {
width = downscaledWidth;
}
} else {
if (originalWidth < originalHeight) {
width = downscaledWidth;
} else if (originalHeight < originalWidth) {
height = downscaledHeight;
}
}
}
UIGraphicsBeginImageContextWithOptions(CGSizeMake(width, height), NO, 1.0);
[image drawInRect:CGRectMake(0, 0, width, height)];
UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return scaledImage;
}
@end
谢谢
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标签： flutter